Non-coordinate expression of closely linked mouse casein genes

Expression levels of five mouse casein genes were analysed in the mammary gland of virgin, pregnant and lactating mice. We have already shown that the five murine casein genes are arranged in the order, alpha-beta-gamma-epsilon-kappa in a tandem array, very close to each other in a 250 kb DNA fragment of mouse genome. Northern blot analysis showed that, of the calcium-sensitive casein genes, the epsilon casein gene is expressed only during lactation unlike the alpha, beta and gamma casein genes which are expressed during pregnancy and lactation. Even though the alpha, beta and gamma genes exhibited a co-ordinated expression pattern from mid to the later stages of pregnancy, the mRNA levels varied considerably (60, 90 and 100% respectively) by the onset of lactation. The mRNA level of the calcium-insensitive kappa casein gene increased from mid-pregnancy but at a lower rate and reached approximately 60% by the first day of lactation. Considering the locations and closeness of the casein genes, a non-coordinate expression profile is exhibited by the mouse casein genes, particularly the epsilon casein gene.

Desensitization of the Y1 cell adrenocorticotropin receptor: evidence for a restricted heterologous mechanism implying a role for receptor-effector complexes

Receptor desensitization provides a potential mechanism for the regulation of adrenocortical adrenocorticotropin (ACTH) responsiveness. Using the mouse adrenocortical Y1 cell line we demonstrate that ACTH effectively desensitizes the cAMP response of its own receptor, the melanocortin 2 receptor (MC2R), in these cells with a maximal effect between 30 and 60 min. Neither forskolin nor isoproterenol (in Y1 cells stably transfected with the beta(2)-adrenergic receptor) desensitize this ACTH response. ACTH desensitizes its receptor at concentrations at which only a fraction of receptors are occupied, implying that this mechanism acts on agonist-unoccupied receptors. Y1 cells express G protein-coupled receptor kinase (GRK) 2 and 5, but stable expression of a dominant negative GRK2 (K220W) only marginally reduces the desensitization by ACTH. The protein kinase A (PKA) inhibitor, H89, extinguishes almost the entire desensitization response over the initial 30-min period at all concentrations of ACTH. A mutant MC2R in which the single consensus PKA phosphorylation site has been mutated (S208A) when expressed in MC2R-negative Y6 cells is also unable to desensitize. These data imply a heterologous, PKA-dependent, mode of desensitization, which is restricted to agonist-occupied and -unoccupied MC2R, possibly as a consequence of receptor/effector complexes that functionally compartmentalize this receptor.

Adults with learning disabilities and epilepsy: knowledge about epilepsy before and after an educational package

The understanding individuals have about their epilepsy may influence the success with which that individual copes with his/her epilepsy. This paper presents the first evaluation of a video-assisted brief educational package for adults with mild learning disabilities and epilepsy ("Epilepsy and You"; Paul, 1996 21). Utilizing a deferred entry to treatment design to evaluate intervention effects eighteen subjects participated in the study. Their knowledge about epilepsy before and after training was assessed using a checklist of knowledge and the Epilepsy Knowledge Questionnaire-Revised for use with people with learning disabilities. Results demonstrated significant gains in knowledge which were durable over a short follow-up period (1 month). "Epilepsy and You" was found to be suitable for use with a wide range of individuals and subjects' opinions demonstrated they enjoyed taking part. This study is a preliminary investigation from which other research can develop. Therefore, criticisms and suggestions for further research have been made.

Pseudoexon activation as a novel mechanism for disease resulting in atypical growth-hormone insensitivity

Inherited growth-hormone insensitivity (GHI) is a heterogeneous disorder that is often caused by mutations in the coding exons or flanking intronic sequences of the growth-hormone receptor gene (GHR). Here we describe a novel point mutation, in four children with GHI, that leads to activation of an intronic pseudoexon resulting in inclusion of an additional 108 nt between exons 6 and 7 in the majority of GHR transcripts. This mutation lies within the pseudoexon (A(-1)-->G(-1) at the 5' pseudoexon splice site) and, under in vitro splicing conditions, results in inclusion of the mutant pseudoexon, whereas the wild-type pseudoexon is skipped. The presence of the pseudoexon results in inclusion of an additional 36-amino acid sequence in a region of the receptor known to be involved in homo-dimerization, which is essential for signal transduction.

Nucleotide sequence of coliphage HK620 and the evolution of lambdoid phages

HK620 is a temperate lambdoid bacteriophage that adsorbs to the O-antigen of its host, Escherichia coli H. The genome of a temperature-sensitive clear-plaque mutant consists of 38,297 nucleotides in which we recognize 60 open reading frames (orfs). Eighteen of these lie in a region of the genome that we call the virion structure domain. The other 42 orfs lie in what we call the metabolic domain. Virions of HK620 resemble those of phage P22. The virion structural orfs encode three kinds of putative proteins relative to the virion proteins of P22: (1) those that are nearly (about 90 %) identical; (2) those that are weakly (about 30 %) identical; and (3) those composed of nearly and weakly identical segments. We hypothesize that these composite proteins form bridges between the virion proteins of the other two kinds. Three of the putative virion proteins that are only weakly identical to P22 proteins are 71, 60 and 79 % identical to proteins encoded by the phage APSE-1, whose virions also resemble those of P22. Because the hosts of APSE-1 and HK620 have been separated from each other by an estimated 200 My, we propose using the amino acid differences that have accumulated in these proteins to estimate a biological clock for temperate lambdoid phages. The putative transcriptional regulatory gene circuitry of HK620 seems to resemble that of phage lambda. Integration, on the other hand, resembles that of satellite phage P4 in that the attP sequence lies between the leftward promoter and int rather than downstream of int. Comparing the metabolic domains of several lambdoid phage genomes reveals seven short conserved sequences roughly defining boundaries of functional modules. We propose that these boundary sequences are foci of genetic recombination that serve to assort the modules and make the metabolic domain highly mosaic genetically.

Population-scale laboratory studies of the effect of transgenic plants on nontarget insects

Studies of the effects of insect-resistant transgenic plants on beneficial insects have, to date, concentrated mainly on either small-scale "worst case scenario" laboratory experiments or on field trials. We present a laboratory method using large population cages that represent an intermediate experimental scale, allowing the study of ecological and behavioural interactions between transgenic plants, pests and their natural enemies under more controlled conditions than is possible in the field. Previous studies have also concentrated on natural enemies of lepidopteran and coleopteran target pests. However, natural enemies of other pests, which are not controlled by the transgenic plants, are also potentially exposed to the transgene product when feeding on hosts. The reduction in the use of insecticides on transgenic crops could lead to increasing problems with such nontarget pests, normally controlled by sprays, especially if there are any negative effects of the transgenic plant on their natural enemies. This study tested two lines of insect-resistant transgenic oilseed rape (Brassica napus) for side-effects on the hymenopteran parasitoid Diaeretiella rapae and its aphid host, Myzus persicae. One transgenic line expressed the delta-endotoxin Cry1Ac from Bacillus thuringiensis (Bt) and a second expressed the proteinase inhibitor oryzacystatin I (OC-I) from rice. These transgenic plant lines were developed to provide resistance to lepidopteran and coleopteran pests, respectively. No detrimental effects of the transgenic oilseed rape lines on the ability of the parasitoid to control aphid populations were observed. Adult parasitoid emergence and sex ratio were also not consistently altered on the transgenic oilseed rape lines compared with the wild-type lines.

The RadB protein from Pyrococcus does not complement E. coli recA mutations in vivo

A previous publication claimed that the radB gene called Pk-REC from Pyrococcus furiosus complemented an E. coli recA mutation. We found that a sequencing error had led to the test of a mutant form of Pk-REC. The wild-type radB gene from P. furiosus cloned in a similar expression vector to the mutant Pk-REC also appeared to complement an E. coli recA mutation. However, the cloned P. furiosus gdh (glutamate dehydrogenase) gene showed the same activity. We therefore concluded that overexpression of any protein can produce an artificial growth inhibition or stationary phase in recA mutant cells, which allows cells to recover from UV damage due to the action of repair systems that do not require RecA-like activity.

Deletion of the alpha(1,3)galactosyl transferase (GGTA1) gene and the prion protein (PrP) gene in sheep

Nuclear transfer offers a cell-based route for producing precise genetic modifications in a range of animal species. Using sheep, we report reproducible targeted gene deletion at two independent loci in fetal fibro-blasts. Vital regions were deleted from the alpha(1,3)galactosyl transferase (GGTA1) gene, which may account for the hyperacute rejection of xenografted organs, and from the prion protein (PrP) gene, which is directly associated with spongiform encephalopathies in humans and animals. Reconstructed embryos were prepared using cultures of targeted or nontargeted donor cells. Eight pregnancies were maintained to term and four PrP-/+ lambs were born. Although three of these perished soon after birth, one survived for 12 days. These data show that lambs carrying targeted gene deletions can be generated by nuclear transfer.

Chromosomal sequences flanking an efficiently expressed transgene dramatically enhance its expression

The expression of transgenes in mice is influenced strongly by their site of integration in the genome. To test whether the chromosomal sequences immediately flanking a site of integration could positively influence expression we isolated the 5' and 3' chromosomal sequences from an efficiently expressed transgenic locus. These chromosomal sequences were incorporated into transgene constructs and these were then introduced into mice. Linking them to the original transgene dramatically enhanced its expression and conferred a degree of position independent expression upon it. However, the results were not as marked when these sequences were linked to other constructs, showing that the effectiveness of such flanking chromosomal sequences is highly dependent on the nature of the transgene used.

Gene targeting in livestock: a preview

Until recently genetically modified livestock could only be generated by pronuclear injection. The discovery that animals can be cloned by nuclear transfer from cultured somatic cells means that it will now be possible to achieve gene targeting in these species. We discuss current developments in NT, the prospects and technical challenges for introducing targeted changes into the germline by this route, and the types of application for which this new technology will be used.

The molecular pathogenesis of ACTH insensitivity syndromes

ACTH insensitivity results from a group of rare autosomal recessive genetic defects. Familial glucocorticoid deficiency is one of these syndromes in which about half of all cases have inactivating mutations of the ACTH receptor. The remaining patients with this syndrome have defects in one or more other as yet unidentified genes that are unlinked to the ACTH receptor. The triple A syndrome is a distinct clinical syndrome which includes alacrima (absence of tears), achalasia and various neurological defects in addition to ACTH insensitivity. In all cases the defect lies in a gene located on chromosome 12.

Triple A syndrome is caused by mutations in AAAS, a new WD-repeat protein gene

The triple A syndrome (MIM 231550) is a rare autosomal recessive disorder characterized by adrenal insufficiency, achalasia and alacrima. The frequent association with a variety of neurological features may result in a severely disabling disease. We previously mapped the syndrome to a 6 cM interval on chromosome 12q13 and have now refined the critical region to 0 cM between KRT8 and D12S1651. Overlapping bacterial artificial chromosome (BAC) sequences of a high resolution BAC/P1-derived artificial chromosome (PAC) contig were screened for gene content and a novel gene encoding a 546 amino acid polypeptide was identified. In nine triple A syndrome patients eight different homozygous and compound heterozygous mutations were found in this gene, most of them leading to a truncated protein suggesting loss of function. RNA blotting experiments revealed marked expression in neuroendocrine and gastrointestinal structures, which are predominantly affected in triple A syndrome, supporting the hypothesis that mutations in this triple A syndrome gene (AAAS) are responsible for the disease. The predicted protein belongs to the family of WD repeat-containing proteins which exhibit a high degree of functional diversity including regulation of signal transduction, RNA processing and transcription.

The CpG island promoter of the human proopiomelanocortin gene is methylated in nonexpressing normal tissue and tumors and represses expression

Ectopic secretion of ACTH, from sites such as small cell lung cancer (SCLC), results in severe Cushing's syndrome. ACTH is cleaved from POMC. The syndrome may occur when the highly tissue-specific promoter of the human POMC gene (POMC) is activated. The mechanism of activation is not fully understood. This promoter is embedded within a defined CpG island, and CpG islands are usually considered to be unmethylated in all tissues. We demonstrate that much of this CpG island is methylated in normal nonexpressing tissues, in contrast to somatically expressed CpG island promoters reported to date, and is specifically unmethylated in expressing tissues, tumors, and the POMC-expressing DMS-79 SCLC cell line. A narrow 100-bp region is free of methylation in all tissues. E2F factors binding to the upstream domain IV region of the promoter have been shown to be involved in the expression of POMC in SCLC. We show that these sites are methylated in normal nonexpressing tissues, which will prevent binding of E2F, but are unmethylated in expressing tissue. Methylation in vitro is sufficient for silencing of expression, which is not reversed by treatment with Trichostatin A, suggesting that inhibition of expression may be mediated by means other than recruitment of histone deacetylase activity. The DMS-79 cells lack POMC demethylating activity, implying that the methylation and expression patterns are likely to be set early or before neoplastic transformation, and that targeted de novo methylation might be a potential therapeutic strategy.

Beta-arrestin- and dynamin-dependent endocytosis of the AT1 angiotensin receptor

The major mechanism of agonist-induced internalization of G protein-coupled receptors (GPCRs) is beta-arrestin- and dynamin-dependent endocytosis via clathrin-coated vesicles. However, recent reports have suggested that some GPCRs, exemplified by the AT1 angiotensin receptor expressed in human embryonic kidney (HEK) 293 cells, are internalized by a beta-arrestin- and dynamin-independent mechanism, and possibly via a clathrin-independent pathway. In this study, agonist-induced endocytosis of the rat AT1A receptor expressed in Chinese hamster ovary (CHO) cells was abolished by clathrin depletion during treatment with hyperosmotic sucrose and was unaffected by inhibition of endocytosis via caveolae with filipin. In addition, internalized fluorescein-conjugated angiotensin II appeared in endosomes, as demonstrated by colocalization with transferrin. Overexpression of beta-arrestin1(V53D) and beta-arrestin1(1-349) exerted dominant negative inhibitory effects on the endocytosis of radioiodinated angiotensin II in CHO cells. GTPase-deficient (K44A) mutant forms of dynamin-1 and dynamin-2, and a pleckstrin homology domain-mutant (K535A) dynamin-2 with impaired phosphoinositide binding, also inhibited the endocytosis of AT(1) receptors in CHO cells. Similar results were obtained in COS-7 and HEK 293 cells. Confocal microscopy using fluorescein-conjugated angiotensin II showed that overexpression of dynamin-1(K44A) and dynamin-2(K44A) isoforms likewise inhibited agonist-induced AT1 receptor endocytosis in CHO cells. Studies on the angiotensin II concentration-dependence of AT1 receptor endocytosis showed that at higher agonist concentrations its rate constant was reduced and the inhibitory effects of dominant negative dynamin constructs were abolished. These data demonstrate the importance of beta-arrestin- and dynamin-dependent endocytosis of the AT1 receptor via clathrin-coated vesicles at physiological angiotensin II concentrations.

HCf-6, a novel class II hydrophobin from Cladosporium fulvum

C. fulvum, a fungal tomato pathogen, has previously been shown to express a complex family of hydrophobin genes including four class I hydrophobins and one class II hydrophobin. Here we describe a gene for HCf-6, a sixth member of the hydrophobin family and the second class II gene. The protein is predicted to consist of a signal sequence, an N-terminus rich in glycine and asparagine and a C-terminal hydrophobic domain which bears the hall-marks of hydrophobins. In contrast to the previously described class II hydrophobin HCf-5, HCf-6 is expressed in mycelium growing in pure culture and mRNA levels do not increase during sporulation. It is down-regulated by carbon starvation but not by depletion of nitrogen in the growth medium.

Inducible ablation of astrocytes shows that these cells are required for neuronal survival in the adult brain

To study the function of astrocytes in the adult brain, we have targeted the expression of E. coli nitroreductase (NTR) to the astrocytes of transgenic mice under the control of the GFAP promoter. The astrocytes expressing NTR were selectively ablated after administration of the prodrug CB1954, resulting in motor discoordination. Histological examination showed that the region most affected in the brain was the cerebellum, in which the Bergmann glia were eliminated and the granular neurons had degenerated. Specific effects were also noted on the dendrites of the Purkinje cells, and the junction between these neurons and granular layer was disrupted. Astrocyte ablation was associated with a dramatic decrease in the expression of glutamate transporters, which may account for the degeneration of granular neurons since the excitotoxic effects of glutamate result in a similar phenotype. These results provide the first evidence that astrocytes are important for the survival of neurons in the adult brain in vivo.

Deletion of the gene encoding H-FABP/MDGI has no overt effects in the mammary gland

Heart fatty acid binding protein (H-FABP) is expressed abundantly in the mammary gland. A number of in vitro studies have shown that H-FABP is functionally indistinguishable from a factor isolated from this organ, termed mammary derived growth inhibitor (MDGI), which specifically inhibits the proliferation of mammary tissue. We have previously shown that over-expression of H-FABP/MDGI in the mammary gland of transgenic mice has no discernable effects on cell proliferation or differentiation. In this report we describe knockout mouse in which the H-FABP/MDGI gene has been specifically disrupted. The mice exhibit no overt phenotype in the mammary gland, and we conclude that this gene does not play a specific role in regulating the normal development or function of this tissue.

Triple A syndrome--clinical aspects and molecular genetics

The triple A syndrome or Allgrove syndrome (MIM*231550) is characterized by adrenocorticotropic hormone (ACTH) resistant Adrenal insufficiency, Achalasia of the cardia and Alacrima. In addition to the main features, patients frequently suffer from neurological disturbances. Dermatological abnormalities such as palmoplantar hyperkeratosis as well as other signs like short stature, microcephaly and osteoporosis point to the multisystemic character of the disorder. The molecular defect of the autosomal recessively inherited triple A syndrome is not known. We initially performed a systematic genome linkage scan in eight triple A families and were able to map the syndrome to a 6 cM interval on human chromosome 12q13 near the type II keratin gene cluster. A refinement of the triple A critical region was achieved by detailed haplotype analysis in a further 37 families from different ethnic backgrounds. There was no indication of genetic heterogeneity. The achalasia-alacrima (AA) syndrome which has been defined as a distinct clinical entity (MIM 200440) is most likely a variant of the triple A syndrome as shown by haplotype analysis in three AA families. We constructed a high-resolution BAC/PAC-based transcript map of the region which will greatly facilitate the identification of the triple A syndrome gene. The considerable intra- and interfamilial variability of the severity of the disorder implies a variable expression of an impaired pleiotropically acting gene.

The expression of the ACTH receptor

Adrenal glucocorticoid secretion is regulated by adrenocorticotropic hormone (ACTH) acting through a specific cell membrane receptor (ACTH-R). The ACTH-R is a member of the G protein superfamily-coupled receptors and belongs to the subfamily of melanocortin receptors. The ACTH-R is mainly expressed in the adrenocortical cells showing a restricted tissue specificity, although ACTH is recognized by the other four melanocortin receptors. The cloning of the ACTH-R was followed by the study of this gene in human diseases such as familial glucocorticoid deficiency (FGD) and adrenocortical tumors. FGD is a rare autosomal recessive disease characterized by glucocorticoid deficiency, elevated plasma ACTH levels and preserved renin/aldosterone secretion. This disorder has been ascribed to an impaired adrenal responsiveness to ACTH due to a defective ACTH-R, a defect in intracellular signal transduction or an abnormality in adrenal cortical development. Mutations of the ACTH-R have been described in patients with FGD in segregation with the disease. The functional characterization of these mutations has been prevented by difficulties in expressing human ACTH-R in cells that lack endogenous melanocortin receptor activity. To overcome these difficulties we used Y6 cells, a mutant variant of the Y1 cell line, which possesses a non-expressed ACTH-R gene allowing the functional study without any background activity. Our results demonstrated that the several mutations of the ACTH-R found in FGD result in an impaired cAMP response or loss of sensitivity to ACTH stimulation. An ACTH-binding study showed an impairment of ligand binding with loss of the high affinity site in most of the mutations studied.

Tall stature in familial glucocorticoid deficiency

OBJECTIVE

Familial glucocorticoid deficiency (FGD) has frequently been associated with tall stature in affected individuals. The clinical, biochemical and genetic features of five such patients were studied with the aim of clarifying the underlying mechanisms of excessive growth in these patients.

PATIENTS AND METHODS

Five patients with a clinical diagnosis of FGD are described in whom the disorder resulted from a variety of novel or previously described missense or nonsense mutations of the ACTH receptor (MC2-R). All patients demonstrated excessive linear growth over that predicted from parental indices and increased head circumference.

RESULTS

Growth hormone and IGF-I-values were normal. Growth charts suggest that the excessive growth is reduced to normal following the introduction of glucocorticoid replacement. A characteristic facial appearance including hypertelorism, marked epicanthic folds and prominent frontal bossing was noted.

CONCLUSIONS

These findings indicate that ACTH resistance resulting from a defective ACTH receptor may be associated with abnormalities of cartilage and/or bone growth independently of the GH-IGF-I axis, but probably dependent on ACTH actions through other melanocortin receptors.

Beech (Fagus sylvatica) response to ozone exposure assessed with a chlorophyll a fluorescence performance index

This paper describes a relationship between ozone exposure, biomass, visual symptoms and a chlorophyll a fluorescence performance index for young beech trees (Fagus sylvatica). The plants were exposed to four levels of ozone in open-top fumigation chambers (50, 85, 100% of ambient, and 50% of ambient+30 nl l(-1) ozone) that fluctuated in parallel with ambient ozone during a single growing season. The trees were fumigated in the four treatments with ozone levels corresponding to an AOT40 (accumulated exposure above a threshold of 40 nl l(-1)) of 0.01, 3.35, 7.06 and 19.70 microl l(-1) h, respectively. Highly significant differences were found between the 50% of ambient+30 nl l(-1) ozone treatment and all other treatments, with a 70.5% reduction in primary photosynthetic performance, as measured with the PI index. The reduction of the PI values demonstrated a high correlation with visual symptom development (r(2)=0.98), and by the end of September with biomass loss (r(2)=0.99). A significant ozone exposure-response relationship was found between AOT40 and primary photochemistry (r(2)=0.97). Thus, analysis of PI provides an alternative method for regional monitoring of tree health within the context of the currently employed AOT40.

Methionine synthase, a gene required for methionine synthesis, is expressed in planta by Cladosporium fulvum

Abstract The nutritional requirements of phytopathogenic fungi growing in planta has to date been largely ignored. We have begun to address this problem by investigating the methionine requirement for the biotrophic pathogen of tomato Cladosporium fulvum during infection. The Met6 gene from Cladosporium fulvum encoding a cobalamin-independent 5-methyltetrahydropteroyltriglutamate-homocysteinemethyltransferase, was cloned by functional yeast complementation. The open reading frame was found to be 2304 bp, containing no introns and encoding a protein of 87 kDa. In vitro Northern analysis demonstrated high levels of Met6 expression in the absence of externally supplied methionine. However in the presence of methionine or in the absence of carbon, expression of Met6 decreased significantly. Analysis of Met6 expression in planta revealed a strong increase during infection suggesting the requirement for methionine synthesis in planta by Cladosporium fulvum. This study demonstrates that Cladosporium fulvum is starving for methionine during infection and thus implies the essentiality of primary biosynthetic pathways to the infecting fungus.

Mechanisms and functions of AT(1) angiotensin receptor internalization

The type 1 (AT(1)) angiotensin receptor, which mediates the known physiological and pharmacological actions of angiotensin II, activates numerous intracellular signaling pathways and undergoes rapid internalization upon agonist binding. Morphological and biochemical studies have shown that agonist-induced endocytosis of the AT(1) receptor occurs via clathrin-coated pits, and is dependent on two regions in the cytoplasmic tail of the receptor. However, it is independent of G protein activation and signaling, and does not require the conserved NPXXY motif in the seventh transmembrane helix. The dependence of internalization of the AT(1) receptor on a cytoplasmic serine-threonine-rich region that is phosphorylated during agonist stimulation suggests that endocytosis is regulated by phosphorylation of the AT(1) receptor tail. beta-Arrestins have been implicated in the desensitization and endocytosis of several G protein-coupled receptors, but the exact nature of the adaptor protein required for association of the AT(1) receptor with clathrin-coated pits, and the role of dynamin in the internalization process, are still controversial. There is increasing evidence for a role of internalization in sustained signal generation from the AT(1) receptor. Several aspects of the mechanisms and specific function of AT(1) receptor internalization, including its precise mode and route of endocytosis, and the potential roles of cytoplasmic and nuclear receptors, remain to be elucidated.

Investigation of chromosome 17q as a locus for human essential hypertension in African Caribbeans

Essential hypertension is a major risk factor for cardiovascular disease in humans, and originates from both genetic and environmental factors. Data from animal and more recently human studies have indicated the presence of a gene influencing blood pressure on human chromosome 17. This study tested for linkage of markers located on chromosome 17q to essential hypertension in African Caribbean hypertensive families. No support of linkage was found between the markers studied and hypertension, however only genes of a lamda sib value of less than 1.8 could be excluded Journal of Human Hypertension (2000) 14, 385-387