The CapZ interacting protein Rcsd1 is required for cardiogenesis downstream of Wnt11a in Xenopus laevis

Wnt proteins are critical for embryonic cardiogenesis and cardiomyogenesis by regulating different intracellular signalling pathways. Whereas canonical Wnt/β-catenin signalling is required for mesoderm induction and proliferation of cardiac progenitor cells, β-catenin independent, non-canonical Wnt signalling regulates cardiac specification and terminal differentiation. Although the diverse cardiac malformations associated with the loss of non-canonical Wnt11 in mice such as outflow tract (OFT) defects, reduced ventricular trabeculation, myofibrillar disorganization and reduced cardiac marker gene expression are well described, the underlying molecular mechanisms are still not completely understood. Here we aimed to further characterize Wnt11 mediated signal transduction during vertebrate cardiogenesis. Using Xenopus as a model system, we show by loss of function and corresponding rescue experiments that the non-canonical Wnt signalling mediator Rcsd1 is required downstream of Wnt11 for ventricular trabeculation, terminal differentiation of cardiomyocytes and cardiac morphogenesis. We here place Rcsd1 downstream of Wnt11 during cardiac development thereby providing a novel mechanism for how non-canonical Wnt signalling regulates vertebrate cardiogenesis.

Comparative expression analysis of cysteine-rich intestinal protein family members crip1, 2 and 3 during Xenopus laevis embryogenesis

Members of the cysteine-rich intestinal protein (Crip) family belong to the group 2 LIM proteins. Crip proteins are widely expressed in adult mammals but their expression profile and function during embryonic development are still mostly unknown. In this study, we have described for the first time the spatio-temporal expression pattern of the three family members crip1, crip2 and crip3 during Xenopus laevis embryogenesis by RT-PCR and whole mount in situ hybridization approaches. We observed that all three genes are expressed in the pronephros, branchial arches and the eye. Furthermore, crip1 transcripts could be visualized in the developing cranial ganglia and neural tube. In contrast, crip2 could be detected in the cardiovascular system, the brain and the neural tube while crip3 was expressed in the cranial ganglions and the heart. Based on these findings, we suggest that each crip family member may play an important role during embryonic development.

An Epha4/Sipa1l3/Wnt pathway regulates eye development and lens maturation

The signal-induced proliferation associated family of proteins comprises four members, SIPA1 and SIPA1L1-1L3. Mutations of the human SIPA1L3 gene result in congenital cataracts. In Xenopus, loss of Sipa1l3 function led to a severe eye phenotype that was distinguished by smaller eyes and lenses including lens fiber cell maturation defects. We found a direct interaction between Sipa1l3 and Epha4, building a functional platform for proper ocular development. Epha4 deficiency phenocopied loss of Sipa1l3 and rescue experiments demonstrated that Epha4 acts up-stream of Sipa1l3 during eye development. Both, Sipa1l3 and Epha4 are required for early eye specification. The ocular phenotype, upon loss of either Epha4 or Sipa1l3, was partially mediated by rax. We demonstrated that canonical Wnt signaling is inhibited downstream of Epha4/Sipa1l3 during normal eye development. Depletion of either Sipa1l3 or Epha4 resulted in an up-regulation of axin2 expression, a direct Wnt/β-catenin target gene. In line with this, Sipa1l3 or Epha4 depletion could be rescued by blocking Wnt/β-catenin or activating non-canonical Wnt signaling. We therefore conclude that this pathomechanism prevents proper eye development and maturation of lens fiber cells resulting in congenital cataracts.

sox4 and sox11 function during Xenopus laevis eye development

SoxC genes are involved in many developmental processes such as cardiac, lymphoid, and bone development. The SoxC gene family is represented by Sox4, Sox11, and Sox12. Loss of either Sox4 or Sox11 function is lethal during mouse embryogenesis. Here, we demonstrate that sox4 and sox11 are strongly expressed in the developing eye, heart as well as brain in Xenopus laevis. Morpholino oligonucleotide mediated knock-down approaches in anterior neural tissue revealed that interference with either Sox4 or Sox11 function affects eye development. A detailed analysis demonstrated strong effects on eye size and retinal lamination. Neural induction was unaffected upon Sox4 or Sox11 MO injection and early eye field differentiation and cell proliferation were only mildly affected. Depletion of both genes, however, led independently to a significant increase in cell apoptosis in the eye. In summary, Sox4 and Sox11 are required for Xenopus visual system development.

Analysis of total aerobic viable counts in raw fish by high-throughput optical oxygen respirometry

A simple, miniaturized, and automated screening assay for the determination of total aerobic viable counts in fish samples is presented here. Fish tissue homogenates were prepared in peptone buffered water medium, according to standard method, and aliquots were dispensed into wells of a 96-well plate with the phosphorescent, oxygen-sensing probe GreenLight. Sample wells were covered with mineral oil (barrier for ambient oxygen), and the plate was monitored on a standard fluorescent reader at 30°C. The samples produced characteristic profiles, with a sharp increase in fluorescence above the baseline level at a certain threshold time, which could be correlated with initial microbial load. Five different fish species were analyzed: salmon, cod, plaice, mackerel, and whiting. Using a conventional agar plating method, the relationship between the threshold time and total aerobic viable counts load (in CFU per gram) was established, calibration curve generated, and the test was validated with 169 unknown fish samples. It showed a dynamic range of 10(4) to 10(7) CFU/g, accuracy of ± 1 log(CFU/g), assay time of 2 to 12 h (depending on the level of contamination), ruggedness with respect to the key assay parameters, simplicity (three pipetting steps, no serial dilutions), real-time data output, high sample throughput, and automation. With this test, quality of fish samples, CFU-per-gram levels, and their respective time profiles were determined.

A superior early myocardial infarction marker

Human heart-type fatty acid-binding protein (FABP) has a high potential as an early marker for myocardial infarction (MI) being more specific than myoglobin. FABP is a low molecular mass cytoplasmic protein (15 kDa) that is released early after the onset of ischemia and it may be useful for rapid confirmation or exclusion of acute myocardial infarction (AMI). Immunochemically assayed FABP, cardiac troponin I (cTnI) and enzymatically assayed creatine phosphokinase (CPK) were determined serially in plasma and serum samples from 218 patients presenting with chest pain and suspected MI. In the 94 patients with confirmed MI, FABP rose to a maximum level (577.6 +/- 43.8 microg/L) 3 hours after the onset of symptoms and returned to normal within 30 hours. The FABP level peaked 7-9 hours earlier than CPK (2288 +/- 131 U/L) and cTnI (357.1 +/- 23.9 microg/L). CPK took 50-70 hours to return to normal level and cTnI returned to normal level over 70 hours. The areas under the receiver operating characteristic (ROC) curves for FABP were calculated as 0.871 at admission and 0.995 one hour after admission, whereas for CPK the areas were 0.711 and 0.856 and for cTnI the areas were 0.677 and 0.845, indicating that the FABP test gave a better diagnostic classification at the early stage being reached by cTnI (0.995) only 8 hours after admission. For FABP, both sensitivity and negative predictive value (NPV) increased quickly to 100% for samples monitored just one hour after admission. By using only two samples, one at admission and one 1 hour post admission, sequential FABP monitoring can reliably diagnose AMI patients 1 hour after admission and 100% of non-AMI patients can be excluded with no false negative results. The late markers cTnI and CPK have the similar diagnostic performance only 7 hours later. Thus measurement of FABP in plasma or serum allows the earliest immunochemical confirmation or exclusion of AMI.

[Functional magnetic resonance imaging and dementia]

Currently, different cerebral neuroimaging methods are being applied to varying questions in the diagnosis of dementia. In patients with manifest Alzheimer's disease a reduction of cortical perfusion and metabolism in temporal and temporoparietal regions has been demonstrated when compared to healthy controls on a diversity of memory tasks. Since differing levels of performance and varying degrees of cortical atrophy may influence functional results considerably, an understanding of the processes associated with normal ageing is perceived as prerequisite for studies applying functional neuroimaging. The integration of knowledge concerning neuropsychological and neurobiological alterations associated with healthy ageing allows hypotheses for the differentiation of pathological ageing processes to be phrased. In this connection non-invasive methods such as fMRI and ASL are of increasing importance.

PET findings and neuropsychological deficits in a case of Fahr's disease

In a case of Fahr's disease with frontal lobe type dementia and hyperkinetic-hypotone syndrome, functional changes were investigated using positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) as a tracer. Computed tomography showed bilateral calcifications in the putamen and globus pallidus consistent with the diagnosis of Fahr's disease and a frontally pronounced brain atrophy. In contrast, reduced glucose uptake in PET was not only confined to the areas mentioned above, but extended to the temporal and parietal cortices, bilaterally. These functional changes corresponded to the neuropsychological deficits observed, i.e. disturbed selective attention and cognitive flexibility, verbal perseverations, and declarative memory deficits. It is suggested that functional changes may precede cerebral atrophy in Fahr's disease and may reflect deficits in functional circuits, which involve both the basal ganglia and the frontal, parietal, and temporal lobes.

Hopping transport of positrons in hydrogenated amorphous silicon

Positron beam timing spectroscopy has been used to investigate positron diffusion in hydrogenated amorphous silicon between 85 and 350 K. The diffusivity is determined from both the contribution of the surface, where the positrons have a different characteristic annihilation rate, and its effect on the shape of the bulk annihilation rate distribution. We observe a single positron state with a temperature independent lifetime of 322 ps. From the temperature dependence of the positron diffusion we show that this is a localized state and present the first ever direct observation of hopping diffusion of positrons in solids. The migration enthalpy for positrons in this state is found to be 17.7(3) meV.

The antifolate trimetrexate: observation of the enzyme-binding conformation

The crystal structure of the title compound contains four 2, 4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl]quinazoline molecules, two dimethyl sulfoxide molecules and three water molecules in the asymmetric unit, i.e. 4C(19)H(23)N(5)O(3).-2C(2)H(6)OS.3H(2)O. All four quinazoline molecules adopt trans,-gauche conformations. An extensive hydrogen-bond network involving N. N base-pairing interactions, as well as the dimethyl sulfoxide and water molecules, stabilizes the crystal structure.

Ranitidine hydrochloride, a polymorphic crystal form

In the title compound, dimethyl(¿5-[2-(1-methylamino-2-nitroethenylamino)ethylthiometh yl]-2- furyl¿methyl)ammonium chloride, C(13)H(23)N(4)O(3)S(+).Cl(-), protonation occurs at the dimethylamino N atom. The ranitidine molecule adopts an eclipsed conformation. Bond lengths indicate extensive electron delocalization in the N,N'-dimethyl-2-nitro-1, 1-ethenediamine system of the molecule. The nitro and methylamino groups are trans across the side chain C=C double bond, while the ethylamino and nitro groups are cis. The Cl(-) ions link molecules through hydrogen bonds.

The frequency of occurrence of anti-cardiac receptor autoantibodies and their correlation with clinical manifestation in patients with hypertrophic cardiomyopathy

The purpose of this study was to investigate the frequency of occurrence of autoantibodies against G-protein coupled cardiovascular receptors and their relation to the clinical manifestation of hypertrophic cardiomyopathy (HCM). Autoantibodies against beta1-receptors, Muscarin-2-receptors, Angiotensin-II-receptor subtype 1 and alpha1-receptors were determined with ELISA in 52 patients with HCM (37 male, 15 female, mean age 55 +/- 15 years) and 40 healthy, age and sex matched controls. The clinical characterization of the HCM-patients included ECG, 24-h Holter, and echocardiography. The results showed that there is no significant difference in the frequency of a single autoantibody between HCM-patients and controls. However, if the number of patients who have autoantibodies against beta1-receptors and/or Muscarin-2-receptors were counted together, there are significantly more autoantibodies in HCM compared to controls (11 vs. 2, p = 0.035). Analysis of clinical data from this pooled group of patients showed that in patients with autoantibodies, heart rate variability (HRV), ultra low frequency (ULF) and very low frequency (VLF) were decreased (HRV by 20%, ULF by 50%, and VLF by 46%, p < 0.008) whereas the QTc-interval was increased by 8% (p < 0.02 each). The ratio of septal to posterior wall thickness was increased by 23% (p = 0.05), and the preejection period was prolonged by 46% in patients with autoantibodies (p < 0.001). These results suggest that the existence of these autoantibodies could be associated with an advanced stage or a severe manifestation of HCM.

Bis(2,2-dimethylaziridinyl)phosphinic amide

The asymmetric unit of the title compound, C8H18N3OP, contains one bis(2,2-dimethylaziridinyl)phosphinic amide molecule. The crystal structure is characterized by hydrogen bonds from the amide-N atom, which involve both H atoms of the amino group, to the phosphinic-O atom in two different molecules, thus forming infinite double-stranded chains along the base vector [100], and by hydrophobic contacts between these chains.

Calcium antagonists ameliorate ischemia-induced endothelial cell permeability by inhibiting protein kinase C

BACKGROUND

Dihydropyridines block calcium channels; however, they also influence endothelial cells, which do not express calcium channels. We tested the hypothesis that nifedipine can prevent ischemia-induced endothelial permeability increases by inhibiting protein kinase C (PKC) in cultured porcine endothelial cells.

METHODS AND RESULTS

Ischemia was induced by potassium cyanide/deoxyglucose, and permeability was measured by albumin flux. Ion channels were characterized by patch clamp. [Ca2+]i was measured by fura 2. PKC activity was measured by substrate phosphorylation after cell fractionation. PKC isoforms were assessed by Western blot and confocal microscopy. Nifedipine prevented the ischemia-induced increase in permeability in a dose-dependent manner. Ischemia increased [Ca2+]i, which was not affected by nifedipine. Instead, ischemia-induced PKC translocation was prevented by nifedipine. Phorbol ester also increased endothelial cell permeability, which was dose dependently inhibited by nifedipine. The effects of non-calcium-channel-binding dihydropyridine derivatives were similar. Analysis of the PKC isoforms showed that nifedipine prevented ischemia-induced translocation of PKC-alpha and PKC-zeta. Specific inhibition of PKC isoforms with antisense oligodeoxynucleotides demonstrated a major role for PKC-alpha.

CONCLUSIONS

Nifedipine exerts a direct effect on endothelial cell permeability that is independent of calcium channels. The inhibition of ischemia-induced permeability by nifedipine seems to be mediated primarily by PKC-alpha inhibition. Anti-ischemic effects of dihydropyridine calcium antagonists could be due in part to their effects on endothelial cell permeability.

A Schiff base formed from sulfanilic acid and dimethylformamide

The crystal structure the Schiff base contains one 4-dimethylaminomethyleneaminobenzenesulfonic acid molecule in zwitterionic form [4-(dimethylaminomethyleneammonio)benzenesulfonate], and one water molecule in the asymmetric unit (C9H12N2O3S.H2O). Protonation occurs at nitrogen atom N1, but the charge is delocalized.

FF-beta-D-arabinofuranosyluracil

In the title compound, 1-(2-deoxy-2-fluoro-beta-D-arabino-furanosyl)-5-fluoropyrimidine-2, 4(1H,3H)-dione, C9H10-F2N2O5, the furanosyl ring adopts the twisted conformation (T) with O1' endo and C1' exo. The crystal structure is characterized by a three-dimensional hydrogen-bond network involving the three H atoms bonded to heteroatoms.

Methylenecyclopropane analogues of nucleosides: synthesis, absolute configuration, and enantioselectivity of antiviral effect of (R)-(-)- and (S)-(+)-synadenol

Synthesis, absolute configuration and antiviral activity of enantiomeric antiviral agents (R)-(-)- and (S)-(+)-synadenol (2 and 3a) are described.

Assaultive eye injury and enucleation

An especially dangerous behavior observed in some forensic and security hospital populations is assaultive eye gouging. Although a number of case reports in the literature concern auto-enucleation, gouging out the eyes of another is virtually unmentioned. We present a case series of eye gougers (n = 10) gathered through clinical contributions from several forensic populations in the United States and Russia. Four subjects were psychotic during the eye-gouging episode, one was only mentally retarded, and five, who were neither psychotic nor retarded, deliberately injured victims' eyes during acts of extreme sexual violence.

(R)-(-)- and (S)-(+)-Synadenol: synthesis, absolute configuration, and enantioselectivity of antiviral effect

Synthesis of (R)-(-)- and (S)-(+)-synadenol (1a and 2a, 95-96% ee) is described. Racemic synadenol (1a + 2a) was deaminated with adenosine deaminase to give (R)-(-)-synadenol (1a) and (S)-(+)-hypoxanthine derivative 5. Acetylation of the latter compound gave acetate 6. Reaction with N, N-dimethylchloromethyleneammonium chloride led to 6-chloropurine derivative 7. Ammonolysis furnished (S)-(+)-synadenol (2a). Absolute configuration of 1a was established by two methods: (i) synthesis from (R)-methylenecyclopropanecarboxylic acid (8) and (ii) X-ray diffraction of a single crystal of (-)-synadenol hydrochloride. Racemic methylenecyclopropanecarboxylic acid (10) was resolved by a modification of the described procedure. The R-enantiomer 8 was converted to ethyl ester 13 which was brominated to give vicinal dibromides 14. Reduction with diisobutylaluminum hydride then furnished alcohol 15 which was acetylated to the corresponding acetate 16. Alkylation-elimination procedure of adenine with 16 yielded acetates 17 and 18. Deprotection with ammonia afforded a mixture of Z- and E-isomers 1a and 19 of the R-configuration. Comparison with products 1a and 2a by chiral HPLC established the R-configuration of (-)-synadenol (1a). These results were confirmed by X-ray diffraction of a single crystal of (-)-synadenol hydrochloride. The latter forms a pseudosymmetric dimer with adenine-adenine base pairing in the lattice with the nucleobase in an anti-like conformation. Enantiomers 1a and 2a exhibit varied enantioselectivity toward different viruses. Both enantiomers are equipotent against human cytomegalovirus (HCMV) and varicella zoster virus (VZV). The S-enantiomer 2a is somewhat more effective than R-enantiomer 1a in herpes simplex virus 1 and 2 (HSV-1 and HSV-2) assays. By contrast, enantioselectivity of antiviral effect is reversed in Epstein-Barr virus (EBV) and human immunodeficiency virus type 1 (HIV-1) assays where the R-enantiomer 1a is preferred. In these assays, the S-enantiomer 2a is less effective (EBV) or devoid of activity (HIV-1).

Atrial natriuretic peptide clearance receptor participates in modulating endothelial permeability

The atrial natriuretic peptide (ANP)-C receptor is generally believed to clear ANP; however, the ANP-C receptor may serve to reduce cAMP by inhibiting adenylate cyclase. ANP decreases endothelial permeability in coronary endothelial cell monolayers. We tested the hypothesis that part of this effect might be mediated by the ANP-C receptor. We used an endothelial cell monolayer from rat coronary endothelium and measured albumin flux. We applied either ANP or a ring-deleted ANP (C-ANP), which only stimulates the ANP-C receptor. ANP and C-ANP both decreased permeability from 100 pM to 100 nM by 60 and 30%, respectively. ANP increased endothelial cGMP contents 5.5-fold, whereas C-ANP had no effect. ANP reduced endothelial cAMP contents by 75%, which was only partly blocked by pertussis toxin. C-ANP also reduced cAMP; however, this effect was completely blocked by pertussis toxin. Protein kinase G inhibition blocked the ANP-mediated decrease in permeability by 50%. In contrast, pretreatment with pertussis toxin, in the face of protein kinase G inhibition, blocked the effect completely. C-ANP decreased permeability by half the amount of ANP. This C-ANP effect was completely blocked by pertussis toxin but not by protein kinase G inhibition. Isoproterenol (10 microM) increased permeability by almost 50%, which was completely blocked by ANP but only partially blocked by C-ANP. The C-ANP effect was blocked completely by pertussis toxin. Isoproterenol increased cAMP threefold, which was abolished by ANP. C-ANP reduced the isoproterenol-induced increase in cAMP by 50%. Isoproterenol had no effect on cGMP. We conclude that agonist binding to the ANP-C receptor inhibits cAMP production via a Gi protein-coupled signaling system. This inhibition may contribute to the decreased endothelial permeability evoked by ANP in this system.

Endothelial-cell permeability and protein kinase C in pre-eclampsia

BACKGROUND

Oedema and vascular leakage play a part in the pathogenesis of pre-eclampsia. We tested the hypothesis that serum from pre-eclamptic patients increases endothelial-cell permeability and examined possible signal-transduction pathways.

METHODS

We studied eight patients with pre-eclampsia, eight normotensive pregnant women, eight non-pregnant women, five pregnant patients with pre-existing hypertension, and four hypertensive non-pregnant women. Cultured human umbilical-vein endothelial-cell monolayers were used and permeability was measured by albumin flux. The part played by protein kinase C (PKC) signalling was examined by down-regulation with phorbol ester and with the inhibitors Goe 6976 and staurosporine. PKC isoforms were assessed by western blot and confocal microscopy. Antisense oligodesoxynucleotides (ODN) were used to test for specific PKC isoforms.

FINDINGS

Serum from pre-eclamptic women increased endothelial permeability significantly (by 100%, p<0.01). The change in permeability decreased rapidly after delivery. Serum from normotensive pregnant women and non-pregnant women had no effect. Permeability was not influenced by serum from patients with essential hypertension or pregnant patients with pre-existing hypertension. Serum from pre-eclamptic patients induced a translocation of PKC isoforms alpha and epsilon within the cells. Goe 6976 and staurosporine (10(-8) mol/L) inhibited the increase in permeability induced by serum from pre-eclamptic patients. Down-regulation of PKC alpha and, to a lesser extent, PKC epsilon by antisense ODN also inhibited the pre-eclampsia-induced permeability increase.

INTERPRETATION

Serum from pre-eclamptic patients contains a factor or factors that increase endothelial-cell permeability. The effect of pre-eclamptic serum may be mediated by PKC alpha and epsilon.

High glucose concentrations increase endothelial cell permeability via activation of protein kinase C alpha

Endothelial cell permeability is impaired in diabetes mellitus and may be increased by high extracellular glucose concentrations. High glucose activates protein kinase C (PKC), a family of kinases vital to intracellular signaling. We tested the hypothesis that high glucose concentration activates PKC in endothelial cells and leads to an increase in endothelial cell permeability via distinct PKC isoforms. Porcine aortic endothelial cells were used, and the PKC isoforms alpha, delta, epsilon, zeta, and theta were identified in these cells. Glucose caused a rapid dose-dependent increase in endothelial cell permeability, with an EC50 of 17.5 mmol/L. Phorbol 12-myristate 13-acetate (TPA) induced an increase in permeability very similar to that elicited by glucose. The effect of glucose and TPA was totally reversed by preincubating the cells with the PKC inhibitors staurosporine (10(-8) mol/L) and Goe 6976 (10(-8) mol/L). Downregulation of PKC by preincubation with TPA for 24 hours also abolished the effect of glucose and TPA on endothelial cell permeability. High glucose (20 mmol/L) caused an increase in PKC activity at 2, 10, and 30 minutes. Cell fractionation and Western blot analysis showed a glucose-induced translocation of PKC alpha and PKC epsilon. Confocal microscopy confirmed the translocation and showed an association of PKC alpha and PKC epsilon with nuclear structures and the cell membrane. Specific antisense oligodesoxynucleotides (ODNs) against PKC alpha reduced the expression of the isoform, abolished the effects of glucose on endothelial cell permeability completely, and reduced the TPA effect significantly. In contrast, specific antisense ODNs against PKC epsilon had no effect on glucose-induced permeability and only a minor effect on the TPA-induced increase in permeability. We conclude that an increase in extracellular glucose leads to a rapid dose-dependent increase in endothelial cell permeability via the activiation of PKC and that this effect is mediated by the PKC isoform alpha.

ANP protects against reoxygenation-induced hypercontracture in adult cardiomyocytes

It was investigated whether atrial natriuretic peptide (ANP) or the related peptide urodilatin can be used for protecting cardiomyocytes against reoxygenation-induced hypercontracture. Isolated ventricular cardiomyocytes (from adult rats) were used as the experimental model. When the cells were submitted to substrate-free anoxia (135 min) and subsequent reoxygenation (30 min), the onset of reoxygenation provoked their hypercontracture. It was studied whether the temporary presence of ANP or urodilatin (1 nM to 1 microM) or 8-bromo-guanosine 3',5'-cyclic monophosphate (8-BrcGMP; 1 microM to 1 mM) during the last 15 min of anoxia and the first 15 min of reoxygenation prevented hypercontracture. It was found that ANP (1 microM) prevented hypercontracture in 82 +/- 8% (SD), urodilatin (1 microM) in 80 +/- 9%, and 8-BrcGMP (1 mM) in 72 +/- 10% of the cells (n = 40 cells). When ANP (1 microM) was added during the last 15 min of anoxia and the first 15 min of reoxygenation, the cellular concentration of cGMP increased from 0.41 +/- 0.04 to 2.80 +/- 0.81 pmol/mg protein (n = 6 cultures). The results show that the reoxygenation-induced hypercontracture in cardiomyocytes can be attenuated by the temporary presence of the stimulators of particulate guanylate cyclase, ANP or urodilatin.

Dual role of cGMP in modulation of macromolecule permeability of aortic endothelial cells

The effect of guanosine 3',5'-cyclic monophosphate (cGMP) on cytosolic Ca2+ dynamics and associated alterations in macromolecule permeability was investigated in cultured monolayers of aortic endothelial cells. Addition of the membrane-permeable cGMP analogue 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP, 5 x 10(-4)M) or activators of the soluble (3-morpholinosydnonimine, 10(-5) M) or the particulate guanylyl cyclase (atrial natriuretic peptide, 10(-7) M) to unstimulated monolayers led to a decrease in permeability (8-BreGMP: 62 +/- 8% of control) without affecting low basal cytosolic Ca2+ concentration ([Ca2+]i, 87 +/- 8 nM). In contrast, under conditions of elevated [Ca2+]i (503 +/- 95 nM) and increased permeability (155 +/- 7% of control) induced by 10(-6) M ionomycin, 8-BrcGMP, 3-morpholinosydnonimine, or atrial natriuretic peptide provoked a further increase in permeability (8-BrcGMP: 255 +/- 27%). These agents failed to increase permeability when added before or after the ionomycin-triggered transitory rise in [Ca2+]i. The increase in permeability in response to 8-BrcGMP was due to a secondary further rise in [Ca2+]i (758 +/- 87 nM), which was abolished in the absence of extracellular Ca2+, indicating influx of exogenous Ca2+ as the cause. Changes in [Ca2+]i and permeability were inhibited, in the presence of the Rp diastereomer of 8-(4-chlorophenylthio)guanosine 3',5'-cyclic monophosphothioate (2 x 10(-5) M), an inhibitor of the cGMP-dependent protein kinase. These findings show that, depending on [Ca2+]i, cGMP can play opposite roles in endothelial permeability in one and the same cell preparation.

Autosomal dominant hypertension and brachydactyly in a Turkish kindred resembles essential hypertension

We examined a Turkish kindred with a unique form of autosomal dominant hypertension that cosegregates 100% with brachydactyly and maps to chromosome 12p. Affected adults were 10 to 15 cm shorter than unaffected people; however, their body mass index (27 kg/m2) was not different. Blood pressure increased steeply with age in the affected people so that by age 40 years, they had a mean blood pressure of 140 mm Hg, compared with 92 mm Hg in unaffected individuals. Complete clinical, roentgenographic, and laboratory evaluation was performed in 6 subjects, including 24-hour blood pressure measurements and humoral determinations before and after volume expansion with 2 L normal saline over 4 hours followed by volume contraction on the following day with a 20-mmol sodium diet and 40 mg furosemide at 8 AM, noon, and 4 PM. Two affected men aged 46 and 31 years; 3 affected women aged 40, 31, and 30 years; and 1 unaffected man aged 29 years were studied. Systolic pressures ranged from 170 to 250 mm Hg, and diastolic pressures ranged from 100 to 150 mm Hg in affected people; the unaffected man had a blood pressure of 120/70 mm Hg. Thyroid, adrenal, and renal functions were normal; electrolyte and acid-base statuses were normal. Calcium and phosphate homeostasis was normal. Day-night circadian blood pressure rhythm was preserved. The subjects were not salt sensitive; renin, aldosterone, and catecholamine values reacted appropriately to volume expansion and contraction. Affected people had mild cardiac hypertrophy and increased radial artery wall thickness. Fibroblasts from affected people grew more rapidly in culture than from unaffected people. We conclude that this novel form of inherited hypertension resembles essential hypertension.

Neuropeptide Y reduces macromolecule permeability of coronary endothelial monolayers

The effect of neuropeptide Y (NPY) on cellular adenosine 3',5'-cyclic monophosphate (cAMP) contents and macromolecule permeability was studied in cultured monolayers of microvascular coronary endothelial cells from rat. Macromolecule permeability was continuously determined as passage of albumin across the monolayers. NPY (10(-10)-10(-7) M) decreased albumin flux and cellular cAMP content in a dose-dependent manner, with a half-maximal effect on albumin flux at 1.4 x 10(-9) M and on cAMP contents at 0.7 x 10(-9) M. A maximum effect of NPY was observed at 10(-7) M, decreasing albumin flux by 71 +/- 8% and cellular cAMP contents by 80 +/- 9% (mean +/- SD, n = 6, P < 0.05) compared with control. The effect of NPY on albumin flux was not altered in the presence of 10(-5) M indomethacin (an inhibitor of cyclooxygenase) and 10(-5) M NG-nitro-L-arginine (an inhibitor of nitric oxide synthase). NPY (10(-7) M) also antagonized the increase of albumin flux and cAMP content induced by 10(-6) M isoproterenol. Pretreatment of endothelial monolayers with pertussis toxin (1 microgram/ml for 2 h) abolished the effect of NPY on albumin flux and cAMP contents. This study shows that NPY can modulate macromolecule permeability of endothelial monolayers by reducing the cellular cAMP contents. Together with the effect of pertussis toxin, the data suggest that NPY exerts its antiadrenergic effect on cAMP metabolism and endothelial barrier function by receptors linked to adenylyl cyclase via an inhibitory guanosine-binding protein in coronary endothelial cells.

Molecular structure and antioxidant specificity of purpurogallin in three types of human cardiovascular cells

Purpurogallin (PPG) in an active cytoprotector found in certain oak barks. We have shown that PPG prolongs the survival of cultured cardiocytes from rats and rabbits against different oxidants better than do antioxidants such as Trolox (a hydrophilic analogue of vitamin E) in a morphometric assay system. First, we verified by X-ray crystallography that PPG is a bicyclic molecule comprising a phenolic ring fused with a seven-membered ring in a highly planar conformation. In analogues of PPG wherein the two double bonds in the seven membered ring of the parent molecule are saturated or where the four OH groups of the parent compound are substituted by four OCH3 groups, the derivatives are less planar and less protective of the human cells than native PPG. Second, PPG in a concentration-dependent manner protected myocytes and endothelial cells of humans against oxyradicals generated with any one of the following oxyradical generators: (a) xanthine oxidase plus hypoxanthine, (b) menadione, or (c) paraquat. In each case, PPG was more cytoprotective than comparative antioxidants. Also, PPG protected erythrocytes against peroxyl radicals better than the two PPG derivatives mentioned. Third, the cytoprotective action of PPG detected in vitro was accompanied by declines of malondialdehyde. Finally, we observed that PPG chelated ferrous ions and, therefore, can suppress the formation of radicals in the Fenton reaction. Thus, PPG with its molecular architecture and presumably its affinity for ferrous ions protects multiple types of cardiovascular cells against oxyradicals.

Functional antagonism between cAMP and cGMP on permeability of coronary endothelial monolayers

The role of the intracellular second messengers guanosine 3', 5'-cyclic monophosphate (cGMP) and adenosine 3', 5'-cyclic monophosphate (cAMP) in the control of macromolecule permeability was studied in cultured monolayers of microvascular coronary endothelial cells from rat. Macromolecule permeability was determined as passage of fluorescein isothiocyanate (FITC)-labeled albumin across the monolayers. Activation of adenylyl cyclase by the beta-adrenoceptor agonist isoproterenol (Iso; 10(-5) M) and the A2-adenosine receptor agonist 5'-(N-ethylcarboxamido)-adenosine (NECA; 10(-7) M) induced an increase in cellular cAMP contents that was accompanied by an increase in albumin flux. Effects of Iso and NECA on cellular cAMP level and albumin flux could be antagonized by a stimulator of the particular guanylyl cyclase, atrial natriuretic peptide (ANP; 10(-7) M), and stimulators of the soluble guanylyl cyclase, 3-morpholinosydnonimine (SIN-1; 10(-7) M) and sodium nitroprusside (SNP; 10(-6) M). ANP, SIN-1, and SNP also reduced cAMP content and basal macromolecule flux in unstimulated monolayers. 8-Bromoguanosine 3', 5'-cyclic monophosphate (8-BrcGMP; 5 x 10(-6) M), a stimulator of protein kinase G, reduced the increase in albumin flux under Iso (10(-5) M), NECA (10(-7) M), or 8-bromoadenosine 3', 5'-cyclic monophosphate (8-BrcAMP; 5 x 10(-6) M). The present study shows that cGMP and cAMP are functional antagonists in the control of macro molecule permeability.

Participation of acetylpseudouridine in the synthesis of a peptide bond in vitro

Uracil, uridine, and pseudouridine were acetylated by refluxing in acetic anhydride, and the products of acetylation were incubated with a synthetic peptide (1-21) that corresponds to the N-terminal 21 amino acid residues of human myelin basic protein. Peptide bond formation, at the N alpha terminus in peptide 1-21, was obtained with acetyluracil and acetylpseudouridine, but not with acetyluridine. Transfer of an acetyl group from acetyluracil and acetylpseudouridine depended on acetylation in the N-heterocycle. X-ray crystallographic analysis definitively established N-1 as the site of acetylation in acetyluracil. Mass spectrometry of the acetylation products showed that one acetyl group was transferred to peptide 1-21, in water, by either acetyluracil or acetylpseudouridine at pH approximately 6. Release of the acetyl group by acylaminopeptidase regenerated peptide 1-21 (mass spectrometry) and automated sequencing (for five cycles) of the regenerated (deacetylated) peptide demonstrated that the N terminus was intact. The findings are discussed in the context of a possible role for pseudouridine in ribosome-catalyzed peptidyltransfer, with particular reference being made to similarities between the possible mechanism of acyl transfer by acetyluracil/pseudouridine and the mechanism of carboxyl transfer by carboxylbiotin in acetyl CoA carboxylase. The possibility that idiosyncratic appearance of a wide range of acyl substituents in myelin basic protein could be related to a peculiar involvement of ribosomal pseudouridine is mentioned.

Combined homicide-suicides: a review

Although the rate of combined homicide-suicides is low compared with that for suicide alone or homicide, homicide-suicides generate much public concern. In some cases, the homicide-suicide involves annihilation of an entire family or multiple non-family members. A difficult phenomenon to study--in part because the perpetrator is dead--it is, nonetheless, crucial to attempt to advance our understanding of this tragic phenomenon from a psychiatric view. This literature review then addresses demographic variables; proposes two classifications, one based on psychopathology, the other on the relationship between offender and victim; and suggests a three dimensional analytical approach to understanding homicide-suicide: 1) psychopathology and ego deficits of the perpetrator, 2) cumulative and precipitating stressors, and 3) motivation and vector of destructive urges against self and the other victim(s). Finally, some implications for mental health clinicians and forensic experts are offered. In attempting to understand acts of homicide-suicide, inquiry into the following dimensions should be useful: Ego Weakness. What type of mental disorder(s), psychopathology, or personality traits may have contributed to the homicidal-suicidal behavior? Stressors. What type of acute and chronic stressors did the individual experience leading up to this act? Vectors. Whom did the individual select to kill and why? Were some victims more clearly primary and others secondary or incidental?

Molecular properties and myocardial salvage effects of morin hydrate

Morin hydrate is a bioactive pigment found in yellow Brazil wood. Recently, we reported that morin hydrate prolongs the survival of three types of cells from the human circulatory system against oxyradicals generated in vitro. The protection excels that given by equimolar concentrations of ascorbate, mannitol, and Trolox. Here, we demonstrate that, in vivo, morin hydrate at 5 mumol/kg actually reduced by > 50% the tissue necrosis in post-ischemic and reperfused rabbit hearts. Mechanistically, morin hydrate not only scavenges oxyradicals, but also moderately inhibits xanthine oxidase, a free-radical generating enzyme from the ischemic endothelium. Among other possibilities, morin hydrate appears to chelate some metal ions (e.g. Fe2+) in oxyradical formation, although this needs to be examined further. Nuclear magnetic resonance (at 500 mHz) and electron-impact mass spectrometry also supported a molecular formula of C15H10O7 for morin hydrate. Only by X-ray crystallography was it clearly revealed that there are two water molecules attached by intermolecular hydrogen bonds to a morin molecule. Also, the three rings of morin hydrate approach coplanarity. This conformation favours a delocalization of electrons after oxyradical reduction, making morin an effective antioxidant. Thus, we have documented some of the molecular properties and myocardial salvage effects of morin hydrate.

Glucosidase inhibitors: structures of deoxynojirimycin and castanospermine

High-resolution structures of the glucosidase inhibitors deoxynojirimycin (dNM) and castanospermine (CAST) have been determined by X-ray diffraction. The crystal parameters are a = 10.751(3) and 8.788(3) A, b = 9.263(3) and 8.172(3) A, c = 7.719(2) and 6.507(2) A, and space group P2(1)2(1)2(1) and P2(1) for dNM and CAST, respectively. (beta = 105.44(8) degrees for CAST.) The absolute configuration of CAST has also been established. Stereochemical comparisons with natural glucosidase substrates such as maltose and methyl glucoside show great similarities in the positioning of functional groups, and indicate the basis for enzyme inhibition. Conformational comparison between dNM and CAST suggests the greater activity of CAST may be due to the fixed axial positioning of the O6 atom; the results have implications for the design of analogues for potential anti-HIV and other antiviral therapies.

L-alanyl-L-alanyl-L-alanine: parallel pleated sheet arrangement in unhydrated crystal structure, and comparisons with the antiparallel sheet structure

The tripeptide L-alanyl-L-alanyl-L-alanine has been crystallized from a water/dimethylformamide solution in an unhydrated form, with cell dimensions a = 11.849, b = 10.004, c = 9.862 A, beta = 101.30 degrees, monoclinic space group P21 with 4 molecules per cell (2 independent molecules in the asymmetric unit). The structure was determined by direct methods and refined to a discrepancy index R = 0.057. The tri-L-alanine molecules are packed in a parallel pleated sheet arrangement with unusually long amide nitrogen-carbonyl oxygen contacts within sheets. Comparisons are made with the antiparallel pleated sheet structure of tri-L-alanine hemihydrate, previously crystallized from the same solvent system.

[Significance of modern therapeutic procedures in long-term treatment of supraventricular tachyarrhythmias]

To get a quantitative statement concerning the significance of modern therapy in supraventricular tachyarrhythmias 200 consecutive patients who were admitted to a coronary unit were analysed retrospectively. Finally accepted treatment were empirical drug therapy in 85 per cent, electrophysiologically controlled medical treatment in 12.5 per cent, pacemaker therapy in 1 per cent, and ablative procedures (catheter ablation and surgical Kent bundle dissection) in 2.5 per cent. As strictly atrial tachyarrhythmias are prevailing and advantages of electrophysiologically controlled drug therapy are not proven, in the majority of cases of supraventricular tachyarrhythmias empirical medical treatment is sufficient. Only in very few cases it is surpassed by the modern procedures. But, nevertheless these modern methods should be known to find the best treatment in problematical cases.

[Treatment indications of hypertensive blood pressure dysregulation (a 7-year follow-up)]

The results of the present course investigations by means of bicycle ergometry over seven years on patients with vitality-limiting load hypertension in normotensive and initial situation of the borderline blood pressure, respectively, render necessary from the point of view of the authors an increase of the former indications to treatment. Situative measurement of blood pressure only at rest are hereby not sufficient and demand a bicycle-ergometric objectivation of the possible hypertensive dysregulation of blood pressure in patients with anamnestically restricted range of physical efficacy. In patients with exclusively under load increased vitality-limiting blood pressure values the ergometry represents the diagnostic method of choice.

Age-dependent excretion of alanine aminopeptidase, alkaline phosphatase, gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase in human urine

Urinary excretion of alanine aminopeptidase, alkaline phosphatase, gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase was determined in gel-filtered samples of morning random urine specimens of 442 subjects of various ages (5 days to 58 years). Enzyme excretion related to urinary creatinine (enzyme/creatinine ratio; U/mmol creatinine) significantly decreased with increasing age. Sex-related differences of some enzyme excretions were found in age groups over 6 years. From these investigations, we calculated upper reference intervals (97.5 percentiles) for 5 age-dependent groups of children and adolescents and for one group of adults.