Structural Heart Issues in Dextrocardia: Situs Type Matters.

Background: Patients who are diagnosed with dextrocardia, a rare congenital heart condition in which the heart points toward the right side of the chest, need their specific situs classification (eg, solitus, inversus, ambiguus) ascertained to optimize their care and outcomes. In this report, we discuss the perioperative anesthetic management of a patient presenting with dextrocardia. Case Report: A 44-year-old African American female with a history of hypertension, hyperlipidemia, gastroesophageal reflux disease, and diabetes mellitus type 2 was admitted for shortness of breath, dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea. The patient had been diagnosed with dextrocardia in 2003 at an outside hospital and was asymptomatic prior to this presentation. Chest x-ray revealed bilateral perihilar vascular congestion with bibasilar atelectasis and suspected small bilateral pleural effusions consistent with new-onset congestive heart failure. Preoperative 2-dimensional transthoracic echocardiography revealed an ostium secundum-type atrial septal defect (ASD) with mild left-to-right atrial shunting. The patient's ASD was repaired using a pericardial patch. Conclusion: The anesthetic management of patients presenting with dextrocardia is complex. Preoperative cardiac transthoracic echocardiography can identify cardiac lesions or aberrant anatomy associated with dextrocardia. Proper placement of electrocardiogram electrodes is necessary to avoid false-positive results for perioperative ischemia. Central line access must be adjusted to anatomic variations. Clinicians should have high suspicion for associated pulmonary hypertension and should limit sedatives preoperatively to minimize the cardiovascular effects of hypoxia and/or hypercarbia on the pulmonary vasculature. Finally, high clinical suspicion for respiratory complications should be maintained, as dextrocardia has been associated with respiratory complications secondary to primary ciliary dyskinesia in approximately 25% of patients.

Comparison of spot urine protein creatinine ratio with 24 hour urine protein for estimation of proteinuria.

The objective of our study was to evaluate and standardise the method of spot (random) urine protein creatinine ratio (UP/C) for estimation of proteinuria. The study contained 241 study participants in a tertiary care hospital inclusive of 208 cases and 33 normal volunteers. The 24 hour urine protein estimation was done on 24 hour urine samples and UP/C ratio was calculated on random urine samples. UP/C ratio and 24 hour urine protein estimation had strong correlation with r = 0.9 and p < 0.05 on Pearson's correlation analysis. Receiver operating characteristic analysis showed random UP/C ratio of 0.1171 reliably predicted 24 hour urine total protein equivalent of > 150 mg/24 hrs with sensitivity 100%, specificity 98.1%, positive likelihood ratio 53.5, and negative likelihood ratio 0. UP/C ratio of 3.2 reliably predicted nephrotic range proteinuria at 24 hour urine protein equivalent of > 3.5 g/24 hrs with sensitivity 80%, specificity 100%, positive likelihood ratio 154.4, and negative likelihood ratio 0.2. We conclude that spot/random UP/C ratio is a reliable, simple test to be introduced and adopted in routine practice for monitoring of macro proteinuria.

Effect of preoperative oral sildenafil on severe pulmonary artery hypertension in patients undergoing mitral valve replacement.

AIM: Long standing mitral valve disease is usually associated with severe pulmonary hypertension. Perioperative pulmonary hypertension is a risk factor for right ventricular (RV) failure and a cause for morbidity and mortality in patients undergoing mitral valve replacement. Phosphodiesterase 5 inhibitor-sildenafil citrate is widely used to treat primary pulmonary hypertension. There is a lack of evidence of effects of oral sildenafil on secondary pulmonary hypertension due to mitral valve disease. The study aims to assess the effectiveness of preoperative oral sildenafil on severe pulmonary hypertension and incidence of RV failure in patients undergoing mitral valve replacement surgery. MATERIALS AND METHODS: A total of 40 patients scheduled for mitral valve replacement with severe pulmonary hypertension (RV systolic pressure (RVSP) ≥60 mmHg) on preoperative transthoracic echo were randomly treated with oral sildenafil 25 mg (N = 20) or placebo (N = 20) eight hourly for 24 h before surgery. Hemodynamic variables were measured 20 min after insertion of pulmonary artery catheter (PAC) under anesthesia (T1), 20 min at weaning from cardiopulmonary bypass (CPB) (T2) and after 1,2, and 6 h (T3, T4, T5, respectively) during the postoperative period. RESULTS: Systolic and mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance index (PVRI) were significantly lower (P < 0.0001) in sildenafil group at all times. Ventilation time and postoperative recovery room stay were significantly lower (P < 0.001) in sildenafil group. CONCLUSION: Sildenafil produces significant pulmonary vasodilatory effect as compared with placebo in mitral valve replacement patients with severe pulmonary hypertension. It also reduces ventilation time and intensive care unit (ICU) stay time as compared with placebo. It is concluded that sildenafil is effective in reducing pulmonary hypertension when administered preoperatively in patients with severe pulmonary hypertension undergoing mitral valve replacement surgery.

Biopolymers from vegetable oils via catalyst- and solvent-free "click" chemistry: effects of cross-linking density.

New monomers were prepared by introducing the azide groups in castor, canola, corn, soybean, and linseed oils. Polymerization of the azidated oils with alkynated soybean oil under thermal "click" chemistry conditions (without using a solvent or a catalyst) yielded fully cross-linked elastomers (1-5) of almost the same density (1.05 × 10(-3) kg/m(3)). The degree of cross-linking gradually increased from the castor-derived polymer (220 mol/m(3)) to the linseed-derived polymer (683 mol/m(3)). A systematic correlation between the degree of cross-linking and the thermal and mechanical properties was observed in these biopolymers. Tensile strength (0.62-3.39 MPa) and glass transition temperature (-5 to 16 °C) increased and the linear thermal expansion coefficient decreased in the series from the canola-derived polymer (2) to the linseed-derived polymer (5). The castor-derived polymer (1) that possesses an additional hydroxyl group per fatty acid chain behaved differently.

Evaluation of non cyanide methods for hemoglobin estimation.

BACKGROUND: The hemoglobincyanide method (HiCN) method for measuring hemoglobin is used extensively worldwide; its advantages are the ready availability of a stable and internationally accepted reference standard calibrator. However, its use may create a problem, as the waste disposal of large volumes of reagent containing cyanide constitutes a potential toxic hazard. AIMS AND OBJECTIVE: As an alternative to drabkin`s method of Hb estimation, we attempted to estimate hemoglobin by other non-cyanide methods: alkaline hematin detergent (AHD-575) using Triton X-100 as lyser and alkaline- borax method using quarternary ammonium detergents as lyser. MATERIALS AND METHODS: The hemoglobin (Hb) results on 200 samples of varying Hb concentrations obtained by these two cyanide free methods were compared with a cyanmethemoglobin method on a colorimeter which is light emitting diode (LED) based. Hemoglobin was also estimated in one hundred blood donors and 25 blood samples of infants and compared by these methods. Statistical analysis used was Pearson`s correlation coefficient. RESULTS: The response of the non cyanide method is linear for serially diluted blood samples over the Hb concentration range from 3 gm/dl -20 gm/dl. The non cyanide methods has a precision of + 0.25 g/dl (coefficient of variation= (2.34%) and is suitable for use with fixed wavelength or with colorimeters at wavelength- 530 nm and 580 nm. Correlation of these two methods was excellent (r=0.98). The evaluation has shown it to be as reliable and reproducible as HiCN for measuring hemoglobin at all concentrations. The reagents used in non cyanide methods are non-biohazardous and did not affect the reliability of data determination and also the cost was less than HiCN method. CONCLUSIONS: Thus, non cyanide methods of Hb estimation offer possibility of safe and quality Hb estimation and should prove useful for routine laboratory use. Non cyanide methods is easily incorporated in hemoglobinometers by using very minute quantities of reagents and test sample; hence, these methods can be used to provide point of care testing in blood banks for hemoglobin (Hb) estimation in blood donors.

White light emission from co-precipitated organic nanoparticle composites.

Co-precipitation of 1,4-bis(2-phenyl-1-propen-1-yl)benzene (1) and 2-(4-(2-(4-(3,6-di-tert-butyl-9H-carbazol-9-yl)phenyl)ethynyl)benzylidene) malononitrile (2) that individually form blue-emitting and orange-emitting nanoparticles, respectively, results in the formation of composite fluorescent organic nanoparticles that emit white light. The two components likely align in the head-to-tail fashion in nanoparticles, creating two parallel and strongly coupled transition dipoles. The emission characteristics of the composite was dependent upon the concentration of 1 and 2, and a pure white-light emission (CIE chromaticity coordinates of 0.34, 0.35) was achieved from the composite that was prepared by employing 12 parts of 1 and 1 part of 2.

Catalyst- and solvent-free "click" chemistry: a facile approach to obtain cross-linked biopolymers from soybean oil.

A series of highly cross-linked biopolymers (1-10) was obtained by the copper-catalyzed and the thermal polyaddition of alkynated and azidated soybean oil with suitable diazides and diynes, respectively. Thermal polymerization (heating at 100 °C), which requires no catalyst and no solvent, was observed to be a superior approach, yielding polymers (6-10) with more homogeneous cross-linking. The temperature of decomposition of 6-10 was narrower (∼170 °C) than that of the polymers (1-5) obtained by the copper-catalyzed method (∼210 °C). The glass-transition temperatures of 1-5 were higher (Tg ranging from 9 to 80 °C) than those of the comparable polymers obtained thermally (Tg ranging from -13 to 45 °C) because of the catalyst entrapped in the networks of 1-5. Furthermore, the thermal approach requires less time and is higher yielding, establishing the suitability and ease of polymerization of vegetable oil-derived alkynes or azides through thermal "Click" chemistry. The effects of the structure of the monomers and the nature of the linkers on the thermal properties of 1-10 (e.g., Tg and decomposition temperatures) are detailed.

Pictorial essay: Ultrasonography in 'tennis leg'.

Tennis leg is caused by a rupture of the medial head of the gastrocnemius muscle, usually at its distal musculotendinous junction region. However, tears in this muscle and its tendon are also included under the term 'tennis leg'. It is seen regularly in practice and is an important cause of a painful calf. The common USG findings include: disruption of the pinnate pattern of the distal medial gastrocnemius, usually near the junction of the triceps surae (which is the echogenic line between the gastrocnemius, the soleus, and the plantaris muscles), fluid tracking along the fascia, adjacent hematoma, and intramuscular tears as well as hematomas. USG is useful for confirming the diagnosis, excluding other causes of a painful calf, for assessing the severity of the disease, and in follow-up.

Photophysical study of blue, green, and orange-red light-emitting carbazoles (1).

Simple synthetic procedures have been developed to prepare suitably substituted stable carbazoles B1-B3, G1-G3, and R1-R3. These compounds emit blue, green, and orange-red light, respectively, and show a red-shifted emission in the solid state relative to that in solution. The extent of the shift is highly dependent on the nature and the positions of the substituents. A red-shift as high as 120 nm can be achieved by a suitable substitution, especially by N-substitution of carbazole. The presence of a carbaldehyde or malononitrile group on the carbazole moiety is found to quench fluorescence severely in solution and in the solid state, as indicated by low fluorescence quantum yields of B1 (phi(F) approximately 0.03), B3 (phi(F) approximately 0.04), and G1-G3 (phi(F) approximately 0.04-0.15). However, the effect is not the same for the fluorescence lifetime (tau(F) approximately 1-5.69 ns). The rate constants of radiative and nonradiative deactivation of B1-R3 have been found to be in the range of 6.40 x 10(6) to 9.50 x 10(8) and 1.38 x 10(8) to 9.84 x 10(8), respectively. Lowering the temperature from 25 to -10 degrees C causes a small but distinct red-shift in the emissions and a systematic increase in the phi(F) values of the blue and green emitters. Solvatochromism and concentration-dependent emissions of the compounds are also discussed.

Solvent dependent optical switching in carbazole-based fluorescent nanoparticles.

Suitably substituted ethynylphenyl carbazoles (PBM and PPM) form stable fluorescent organic nanoparticles. The emission of the nanoparticles can be reversibly switched on/off in the blue-green and orange-red regions by a change in the ratio of the tetrahydrofuran/water system used in their preparation. The size of the nanoparticles was found to be dependent on the solvent ratio, and the emissions were significantly red-shifted compared to those of dilute solutions of PBM and PPM in tetrahydrofuran. This is attributed to the formation of intermolecular charge transfer complexes in the nanoparticle state. The application of the nanoparticles as a chemical vapor sensor has been suggested.

Photodecarbonylation of alpha-diketones: a mechanistic study of reactions leading to acenes.

Poly(acene)s are significant compounds for various electronic applications. A clean, one-step synthesis involves alpha-diketones (2-4), which undergo facile Strating-Zwanenburg photodecarbonylation producing the corresponding poly(acene)s (i.e., anthracene, hexacene, and heptacene, respectively). Compounds 2-4 show weak fluorescence (lambdaF=approximately 525-530 nm and PhiF=approximately 0.1-0.4%) and phosphorescence (lambdaPh=approximately 565-570 nm) and have a small singlet-triplet energy gap (S1-T1 gap, approximately 4 kcal/mol) that facilitates rapid intersystem crossing from the singlet to the triplet state. Both the singlet states (tauS=approximately 20-218 ps) and the triplet states (tauT=approximately 370 ps to <7 ns) of 2-4 are short-lived, while the decarbonylation of 2-4 is a rapid process occurring within 7 ns from both the singlet and the triplet manifolds. The nanosecond laser flash photolysis of 4 also reveals the T-T absorption of heptacene (580 nm, tau=approximately 11 micros).

Synthesis of highly soluble and oxidatively stable tetraceno[2,3-b]thiophenes and pentacenes.

A comparative study of suitably functionalized, highly soluble tetraceno[2,3-b]thiophenes (1-3) and pentacenes (4-6) that show higher photoxidative stability than that of unfunctionalized corresponding acenes is reported. The absorption and emission of 1-3 (Amax = 624-656 nm, lambda max = 634-672 nm, PhiF approximately 10%) and 4-6 (Amax = 672-704 nm, lambda max = 682-718 nm, PhiF approximately 10%) were found to be systematically red-shifted by the substitution in the order of the tert-butylethynyl < triisopropylsilylethynyl < phenylethynyl groups. The oxidation potentials of these compounds were similar (E1/2 approximately 0.70 V), except for 4, which showed lower oxidation potential (E1/2 approximately 0.63 V).

Synthesis and photophysical properties of carbazole-based blue light-emitting dendrimers.

A new class of highly fluorescent and stable carbazole-based dendrimers (1-5) that contain the ethynylbenzene and diethynylbenzene cores has been synthesized and characterized. They show very high extinction coefficients of absorption (A(max) approximately 328-353 nm) and high quantum yields of fluorescence (lambda(max) approximately 386-437 nm; Phi(F) approximately 0.72-0.89; tau(F) approximately 2.09-3.91 ns) in dichloromethane. The quantum yields of fluorescence of 1-5 in the solid state are equally high (lambda(max) approximately 385-422 nm; Phi(F) approximately 0.40-0.85). These data indicate their potential use as blue-emitting materials in organic light-emitting diodes (OLEDs).

Revisiting the stability of hexacenes.

The Strating-Zwanenberg photodecarbonylation was used to prepare hexacene (1). Compound 1 was found to be extremely unstable in solution, undergoing dimerization and oxidation. However, when generated in a polymer matrix, 1 survived for more than 12 h under ambient conditions. Hexacenes substituted at the 6 and 15 positions with the phenyl, p-tert-butylphenyl, and mesityl groups were synthesized using the quinone reduction method, but these compounds were also shown to be unstable in solution.

Photogeneration of heptacene in a polymer matrix.

Heptacene (1) was generated by the photodecarbonylation of 7,16-dihydro-7,16-ethanoheptacene-19,20-dione (2) in a polymer matrix using a UV-LED lamp (395 +/- 25 nm). Compound 1 showed a long wavelength absorption band extending from 600 to 825 nm (lambdamax approximately 760 nm) and was found to be stable up to 4 h in the polymer matrix. However, irradiation of a solution of 2 in toluene produced only oxygen adducts.

Synthesis and photophysical properties of dihydroheptacenes: new blue-emitting materials.

7,16-Dihydroheptacenes (1-3) substituted at the 6, 8, 15, and 17 positions are synthesized as blue emitters potentially useful in organic light emitting diodes (OLEDs). The photophysical properties of 1-3 (lambda(max) = 424-428 nm, phi(F) = 0.15-0.21, tau(F) = 2.35-2.67 ns in CH2Cl2) are discussed. They are shown to be stable and efficient blue emitters in the solid state (phi(F) = 0.37-0.44). The X-ray crystal structure of 1 is reported.

Photophysical properties of anthanthrene-based tunable blue emitters.

Anthanthrene (1) derivatives substituted at the 4,10 and 6,12 positions (2-6) were synthesized as promising candidates for organic light emitting diodes (OLEDs). The emission of these compounds can be manipulated in the blue region (lambda(max) = 437-467 nm) through structural modifications. Photophysical and electrochemical properties (phi(F) = 0.20-0.47; tau(F) = 2.97-6.06 ns; HOMO-LUMO energy gap = 2.25-2.56 eV) as well as geometry optimized structures of 1-6 are reported.

Laser flash photolysis of tert-butyl aroylperbenzoates: kinetics of the singlet and triplet states and the aroylphenyl radicals.

tert-Butyl aroylperbenzoates (1-4) were studied by laser flash photolysis (LFP). LFP (380 nm, pulse width approximately 350 fs) of 2 and 3 allowed direct observation of their singlet states, which showed broad absorption (lambda(max) approximately 625 nm; tau approximately 20 and approximately 7.9 ps, respectively). The triplet state of each (lambda(max) approximately 530-560 nm) rapidly dissociates by O-O cleavage as indicated by the short triplet lifetimes (e.g., triplet lifetime of 3 approximately 0.74 ns). The approximately 550 nm absorption obtained from the 355 nm LFP (pulse width approximately 7 ns) of 1, 2, and 4 has been assigned to the corresponding aroylphenyl radicals. Two representative radicals (4-benzoylphenyl 5 and 3-(4'-methylbenzoyl)phenyl 6) investigated in detail showed solvent-dependent lifetimes. Absolute bimolecular rate constants of reactions of these radicals with various quenchers including double-bond-containing monomers have been observed to range from 7.56 x 10(7) to 1.68 x 10(9) M(-1) s(-1) in CCl(4) at room temperature. A possible structure of the aroylphenyl radicals and the transition responsible for the 550 nm absorption are discussed.

Synthesis, crystal structures, and laser flash photolysis of tert-butyl aroylperbenzoates.

tert-Butyl aroylperbenzoates (1-7) were synthesized. Single-crystal structures for 2 and 5 show that the perester and benzophenone carbonyl groups are almost coplanar in each. Laser flash photolysis (LFP, lambdaex = 355 nm) of 1-5 in CCl4 produces the corresponding aroylphenyl radicals (9-13). The lifetimes of the para aroyl-substituted phenyl radicals (9-12) are similar (approximately 0.4 micros), but each is shorter lived than the meta aroyl-substituted phenyl radical (13). LFP of 2, 6, and 7 also produces different (tert-butyldioxycarbonylbenzoyl)benzyl radicals (8, 14, and 15, lambdamax approximately 320 nm). The lifetimes of each in CCl4 have been found to be approximately 17-18 micros. The effect of substituents on the quantum yield of decomposition of 1-7 and the lifetimes of 9-13 is discussed.

Triplet energy distribution in photoinitiators containing two dissociable groups.

Suitable probe molecules containing the benzophenone chromophore and one dissociable bond [perester 1 or C-X (4, 5)] or two such bonds (2, 3) have been synthesized and studied to examine intramolecular triplet energy dispersion. Triplet energies and phosphorescence quantum yields as well as quantum efficiencies of bond scissions have been studied, and the flow of triplet energy in such molecules is discussed. Upon irradiation at 350 nm in either benzene or methanol, the target peresters undergo dissociation of both cleavable groups, producing a pair of radicals. The presence of a benzylic chloride function has little influence on the efficiency of perester dissociation. However, the presence of a benzylic bromide function was found to decrease the quantum yield of decomposition of the perester function of 3. This can be explained by taking into account the effect of the heavy atom and the rate of cage geminate radical pair recombination. The nature of the heavy atom perturbation, however, was found to be different in 5 as compared with 3.