Morning Blood Pressure is Associated with Sleep Quality in Obese Adolescents

Objective To examine relationships between blood pressure (BP), adiposity, and sleep quality using overnight polysomnography (PSG) in obese adolescents. Study design Overnight PSG and morning BP measurements were performed in obese (BMI >97th %ile) non-diabetic adolescents (eligible age range 12-18 years, n=49). Subjects were stratified into two groups, one with normal BP, and one with elevated BP, and demographic and clinical characteristics compared between the groups. Multiple linear regression analysis was used to assess the BP effects of sleep quality measures. Results Participants (n=27) had normal morning BP, and 22 (44.9%) had elevated morning BP. There were no differences in age (p=0.53), sex (p=0.44), race (p=0.58) or BMI (p=0.56) between the two BP groups. The group with elevated BP spent shorter percentages of time in rapid eye movement (REM; p=0.006) and slow-wave sleep (SWS; p=0.024). Multiple linear regression analysis showed a lower percent of both REM and SWS were associated with increased morning BP, after adjusting for pubertal stage, sex, race, and BMI. Conclusion Lack of deeper stages of sleep, REM sleep and SWS, is associated with higher morning BP in obese adolescents, independent of BMI. Poor sleep quality should be considered in the work-up of obese youth with hypertension. Intervention studies are needed to evaluate whether improving the quality of sleep will reduce blood pressure elevation

Left Atrial Posterior Wall Thrombus After Posterior Wall Ablation

Background: Posterior wall isolation for recurrent atrial arrhythmia is a commonly used technique to achieve long-term freedom from atrial fibrillation. Despite the widespread use of posterior wall isolation, its long-term effects on left atrial function are unknown. Specifically, the effect of isolated atrial walls on stasis and risk of thrombus has not been established. We present the case of a patient who developed a left atrial posterior wall thrombus after a posterior wall isolation attempt.Case Report: A 67-year-old female with a complex electrophysiologic history was found to have a left atrial posterior wall thrombus when she presented for a third ablation attempt for drug-refractory macroreentrant left atrial tachycardia 5 weeks after a posterior wall isolation attempt. The patient had a number of risk factors that could have been associated with the unusually located thrombus: hypertension, low ejection fraction, mitral valve disease, and recurrence and sustained duration of symptomatic atrial fibrillation. After the patient had 3 weeks of anticoagulation treatment, transesophageal echocardiography showed no left atrial thrombus, and she underwent successful reisolation of the posterior wall. The third ablation was successful, and the patient developed no complications of stroke, transient ischemic attack, or systemic embolization throughout her treatment course.Conclusion: To our knowledge, this case is the second report of a left atrial posterior wall thrombus in this setting. The patient's complex and specific set of risk factors likely led to this rare finding. Although left atrial posterior wall thrombus after ablation is rare, in patients with specific risks or a combination of factors that could lead to such a clot, visualizing the left atrium in these patients may be beneficial to minimize the risk of systemic embolization

Aldimine→amide conversion via oxygen atom transfer from water mediated by rhenium oxidation states: Reaction model and synthetic utilization for making Re^VINAr species

249-251The conversion of N-p-tolylpyridine-2-aldimine to N-p-tolylpicolinamide chelated to ReVI(OPPh3)CI3 in oxidizing aqueous media is shown to proceed via initial one-electron metal oxidation followed by addition of a water molecule to the aldimine function. Subsequent induced electron transfer in the adduct with concomitant proton loss affords the amide complex. The aldimine→amide reaction is utilized for the synthesis of the N-p-tolylpicolinamide complex of the rare ReVINAr motif

Synthesis and X-ray crystal structure of an oxorhenium(V) complex with a double Schiff base

The reaction of the double Schiff bases, RL, formed from 2,6-diformyl-4-methyl-phenol and p-RC6H4NH2 (R=H, Me, OMe, Cl) with ReOCl3(PPh3)2 afforded red coloured complexes of the type RevOCl3(RL). The X-ray structure of the R = Me complex (crystal data: ReOCl3(MeL)·CH2Cl2, triclinic, space group PI, a = 8.736(2), B=10.632(3), C=10.575(5)Å, a=104.64(2)°, β=93.22(2)°, γ = 110.57(2)°, V = 1376.6(7) Å, Z =2, R = 3.06%, Rw = 3.51%) revealed meridional chloro coordination in an ReOCl3(ON) coordination sphere. The RL ligand binds in the bidentate ON mode, the second imine function occurring in the protonated from (N---H···O hydrogen bonding). IR and 1H NMR data indicate that the solid-state structure is substantially retained in solution. The complexes display a quasi-reversible ReVIO/ReVO couple whole potential depends on the R substituent

Variable-valent ReNAr species. A family of ReVINAr amide complexes and their ReVNAr imine precursors related by oxygen atom transfer

Imide complexes of type ReVCl<SUB>3</SUB>(X-SB)(NC<SUB>6</SUB>H<SUP>4</SUP>Y(p)), with X, Y= H, Me, OMe, Cl have been synthesized where X-SB is the Schiff base of pyridine-2-carboxaldehyde (the corresponding complex is 4), 2-acetylpyridine (5), 2-benzoylpyridine (6), and anilines, p-XC<SUB>6</SUB>H<SUB>4</SUB>NH<SUB>2</SUB>. Treatment of 4 or 5 (but not 6) with aqueous nitric acid in acetonitrile afforded Re<SUP>VI</SUP>Cl<SUB>3</SUB>(X-PA)(NC<SUB>6</SUB>H<SUB>4</SUB>Y(p)), 7, via oxygen atom transfer (X-PA = monoanionic picolinamide). In the structures of 5(X=Cl,Y=Cl), 6(OMe,OMe), and 7(Me,Me), the chlorine atoms are meridionally disposed in a ReCl<SUB>3</SUB>N<SUB>3</SUB> coordination sphere. The trans influence of the imide nitrogen considerably lengthens the Re-N(pyridine) bond. The ReNC<SUB>6</SUB>H<SUB>4</SUB>Y(p) group has the triple-bonded linear moiety, ReN-C. The amide group in 7(Me,Me) is planar. In 6(OMe,OMe) the two aryl rings on the imine function block water attack and hence amide formation. The rhenium(VI)-rhenium(V) E<SUB>1/2 </SUB>values for 4-6 (0.7-1.0 V vs SCE) are much higher than that for 7 (E<SUB>1/2</SUB>~0.15 V), which displays the rhenium(VII)-rhenium(VI) couple near 1.6 V. Six EPR hyperfine lines are observed for solutions of 7 at room temperature (g<SUB>iso</SUB> ~1.91; A<SUB>av</SUB> ~490 G). Crystal data for the complexes are as follows: 5(Cl,Cl), empirical formula C<SUB>19</SUB>H<SUB>15</SUB>C<SUB>l5</SUB>N<SUB>3</SUB>Re, crystal system monoclinic, space group P2<SUB>1</SUB>/c, a = 13.360(6) &#197;, b = 12.110(3) &#197;, c = 14.954(9) &#197;, &#946; = 111.41(4)&#176;, V = 2252.4(1.7) &#197;<SUP>3</SUP>, Z = 4; 6(OMe,OMe), empirical formula C<SUB>26</SUB>H<SUB>23</SUB>C<SUB>l3</SUB>N<SUB>3</SUB>O<SUB>2</SUB>Re, crystal system orthorhombic, space group Pbca, a = 12.079(5) &#197;, b = 17.083(9) &#197;, c = 26.049(9) &#197;, V = 5375.4(4.0) &#197;<SUP>3</SUP>, Z = 8; 7(Me,Me), empirical formula C<SUB>20</SUB>H<SUB>18</SUB>Cl<SUB>3</SUB>N<SUB>3</SUB>ORe, crystal system monoclinic, space group P2<SUB>1</SUB>/c, a = 7.071(2) &#197;, b = 17.541(6) &#197;, c = 16.857(8) &#197;, &#946; = 100.59(3)&#176;, V = 2055.3(1.3) &#197;<SUP>3</SUP>, Z = 4

The first example of a binuclear rhenium(V) oxo-imido system

857-858The reaction of [ReV(O)Cl3(L)] with p-toluidine taken in equimolecular proportion in boiling toluene has afforded the title complex [(L)CI2(O)ReVOReV(NC6H4Me)CI2(L)] (L = 2-(p-chlorophenylazo)pyridine). Structure determination has revealed the presence of an unsymmetri cal oxo bridge (Re-O, 1.849(7) Å and 1.954(7) Å )interlinking ReVO and ReVNAr moieties

Chemistry of monovalent and bivalent rhenium: synthesis, structure, isomer specificity and metal redox of azoheterocycle complexes

The reaction of [ReVO(OEt)X2(PPh3)2] (X = Cl, Br, I) with 2-(arylazo)-1-methylimidazoles (aryl = Ph(L1), C6H4Me–p(L2) or C6H4Cl-p(L3)) as well as 2-(p-tolylazo)-1-benzylimidazole (L4) in toluene has afforded the orange coloured bis chelates of type [ReIIX2(L)2]. The green coloured tris chelates [ReI(L)3]ReO4 are formed when the ligand is used in excess. Similar bis and tris chelates have also been synthesized by reacting [ReOCl3(PPh3)2] with 2-(arylazo)pyridines (aryl = Ph(L5), C6H4Cl-p(L6)). Structure determination of [ReCl2(L2)2], [ReI2(L4)2] and [ReCl2(L6)2] has revealed that the isomeric geometry for the XX–NhNh–NaNa donor sites (Nh, heterocyclic nitrogen; Na, azo nitrogen) is uniformly cis–trans–cis. In the structure of [Re(L)3]ReO4 the tris chelate has facial geometry. The isomer preference of both families is exclusive, no other isomer having been observed in any of the preparations. The 1H NMR spectra of the tris chelates are consistent with the facial geometry. The bis chelates are one-electron paramagnets and display well-resolved EPR sextets in fluid solutions. The cyclic voltammetric ReIII/ReII response of [ReIIX2(L)2] occurs in the range 0.20–0.50 V vs. SCE in the case of the azoimidazole chelates and in the range 0.60–0.70 V in the case of the azopyridine chelates. In the case of [ReI(L)3]+ the ReII/ReI couple is observed near 0.50 and 0.90 V for the azoimidazole and azopyridine species respectively. The average Re–Na distance is generally shorter than the Re–Nh distance by &#8764;0.1 Å and the average N–N length is longer by &#8764;0.1 Å compared to that of uncoordinated azo function. Strong d(Re)–π*(azo) back-bonding characterize the present systems. Both back-bonding and steric factors stabilize the cis–trans–cis isomer of [ReX2(L)2]. In facial [Re(L3)]+ the net back-bonding is strong enough to offset the disadvantage of steric crowding

Synthesis, structure and properties of [Re^VL(O)Cl₃], [Re^VL(NR)Cl₃], [Re^IIIL(OPPh₃)Cl₃], and [Re^IIIL(PPh₃)Cl₃] [L = 2-(arylazo)-1-methylimidazole, R = aryl] †

The reaction of KReO4 with L [2-(arylazo)-1-methylimidazole, with aryl = Ph (L1), C6H4Me-p(L2) or C6H4Cl-p(L3)] in concentrated HCl afforded [ReVL(O)Cl3] 1. Aromatic amines and PPh3 smoothly converted 1 into [ReVL(NR)Cl3] 2 and [ReIIIL(OPPh3)Cl3] 3 respectively. Treatment of 3 with PPh3 yielded [ReIIIL(PPh3)Cl3] 4. Complexes of type 3 and 4 display large paramagnetic shifts of 1H NMR lines which spread over ≈ 60 ppm. Structure determination of [ReL1(O)Cl3] 1a, [ReL2(NC6H4Me-p)Cl3] 2a, [ReL3(OPPh3)Cl3] 3c and [ReL3(PPh3)Cl3] 4c has revealed meridional geometry for all except 4c which is facial. In the latter Re–azo and Re–PPh3 back bonding is maximized. The metal atom is displaced away from the equatorial plane by ≈ 0.3 Å towards the oxo ligand in 1a and the imido ligand in 2a. The imidazole nitrogen is co-ordinated trans to oxo, imido, Ph3PO and chloride ligands in 1a, 2a, 3c and 4c, respectively. The azo N=N distance is lengthened by &#8805; 0.05 Å as a result of direct (3c, 4c) or indirect (1a, 2a) Re–azo back bonding. Azo reduction potential values are consistent with the low-lying nature of the azo(π*) orbital. The metal reduction potentials follow the trends: ReVI–ReV, 1 &#62; 2 (imido better donor than oxo); ReIV–ReIII, 4 &#62; 3 (stabilization of t2 by ReIII–PPh3 back bonding)

Synthesis, structure and redox behaviour of facial [Re^IIIL(PPh₃)Cl₃] and its stereoretentive conversion to [Re^IVL′(PPh₃)Cl₃] via metal promoted aldimine → amide oxidation (L = pyridine-2-aldimine; L′ = pyridine-2-carboxamide)

The reaction of mer-[Re^IIIL(OPPh₃)Cl₃] 2 with PPh₃ in benzene has afforded bluish violet fac-[Re^IIIL(PPh₃)Cl₃] 1, where L is the Schiff base of pyridine-2-carbaldehyde and the substituted aniline p-XC₆H₄NH₂ (X = H, Me, OMe or Cl). Geometrical preferences are rationalized in terms of the electronic nature of the ligands OPPh₃ (σ- and π-donor), PPh₃ (σ-donor and π-acceptor) and L (σ-donor and π-acceptor). The cyclic voltammetric E1/2 values of 1 lie near 0.6 V (Re^IV–Re^III) and –0.6 V (Re^III–Re^II). Electrooxidation of 1 at 1.0 V vs. SCE in wet acetonitrile affords yellow fac-[Re^IVL′(PPh₃)Cl₃] 3 which is also obtainable via oxidation by dilute nitric acid (L′ is a monoanionic pyridine-2-carboxamide). Complex 3 displays Re^IV–Re^III and Re^V–Re^IV couples near –0.2 V and 1.4 V respectively reflecting superior stabilization of the rhenium(IV) state by the amide ligand. The X-ray structures of two representative complexes of type 1 and 3 have revealed the presence of severely distorted and facially configured RePN₂Cl₃ coordination spheres. The average Re–Cl distance is lower by 0.06 Å in 3 due to contraction of the metal radius upon oxidation. The Re–P length is however larger by 0.1 Å in 3 signifying a weakening of Re–P back-bonding