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Background: Despite an epidemic of obesity among adults, the effect of excess body weight on outcome from critical illness is not well studied.Objective: To examine the association between excess body weight and outcome in mechanically ventilated patients with acute lung injury.Design: Secondary analysis of participants in trials of therapy for acute lung injury.Setting: 10 U.S. medical centers that participate in the National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome Network.Patients: 902 mechanically ventilated patients who were enrolled in randomized, controlled trials of therapy for acute lung injury.Intervention: Assignment to higher (12 mL/kg of predicted weight) or lower (6 mL/kg of predicted weight) tidal volume ventilation strategies with specified weaning protocols. Some patients also received ketoconazole, lisofylline, or placebo by factorial design.Measurements: Mortality rate, rate of unassisted ventilation by day 28, and number of ventilator-free days.Results: Indirect causes of lung injury, including trauma, were more common in obese patients. Overweight and obese patients had higher peak and plateau airway pressures before enrollment because of higher set tidal volumes. After risk adjustment, excess body weight was not associated with death, achievement of unassisted ventilation, or number of ventilator-free days. This lack of effect persisted with categorical or continuous measures of body mass index (BMI). We found no significant interaction between ventilator protocol assignment and BMI category.Conclusions: After risk adjustment, overweight and obese patients with acute lung injury have outcomes similar to those of patients with normal BMI. The lack of interaction between ventilator protocol assignment and BMI suggests that patients with normal, overweight, or obese BMI benefit from lower tidal volume ventilation for acute lung injury. [ABSTRACT FROM AUTHOR]

Objectives: This study was designed to determine if women are more likely than men to have heart failure (HF) with preserved systolic function after adjustment for potential confounders, including age.Background: Although prior evidence suggests an independent association between female gender and preserved left ventricular systolic function (LVSF) in patients with HF, existing studies are limited by referral biases, small sample sizes, or the inability to adjust for a wide range of potential confounding variables.Methods: This is a cross-sectional study using data from retrospective medical chart abstraction of a national sample of Medicare beneficiaries hospitalized with the principal discharge diagnosis of HF in acute-care nongovernmental hospitals in the U.S. between April 1998 and March 1999. Patients were eligible for this analysis if they were age 65 years or older, had documentation of LVSF, and corroboration of the diagnosis of HF. We used multivariable logistic regression to identify the correlates of preserved LVSF, which was defined as qualitatively normal function or quantitatively reported ejection fraction > or =0.50. Stratified regressions by gender were performed to identify significant interactions.Results: Of the 19,710 patients in the analysis, preserved LVSF was present in 6,700 (35%), 79% of whom were women. In contrast, among the 12,956 patients with impaired LVSF, only 49% were women. Patients with preserved LVSF were 1.5 years older than those with impaired LVSF. After adjustment for age and other patient factors, female gender remained strongly associated with preserved LVSF (calculated risk ratio = 1.71; 95% confidence interval 1.63 to 1.78). The association was consistent in all age groups, and was similar in patients with or without coronary artery disease, hypertension, pulmonary disease, renal insufficiency, or atrial fibrillation.Conclusions: In elderly patients hospitalized with HF, preserved systolic function is primarily a condition of women, independent of important demographic and clinical characteristics. [ABSTRACT FROM AUTHOR]

The enantioselective reduction of prochiral ketones catalyzed by horse liver alcohol dehydrogenase (HLADH), was investigated via a hybrid computational approach, for molecular reactions involved in chiral synthesis of S-alcohols, when the natural co-factor, 1,4-dihyronicotinamide adenine dinucleotide, 1,4-NADH, was replaced with biomimetic co-factor, N-benzyl-1,4-dihydronicotinamide, 1. We surmised that different hydride and proton transfer mechanisms were involved using co-factor, 1. An alternative mechanism, where the hydride transfer step occurred, via an η 1 -keto-S-η 2 -5,6-1,4-dihydronicotinamide-Zn(II) complex, was previously investigated with a model of the HLADH-Zn(II) catalytic site (J. Organometal. Chem. 2021, 943, 121810). Presently, we studied canonical and alternative mechanisms compared to models of the entire enzyme structure. We disproved the η 2 -Zn(II) complex, and discovered a canonical hydride transfer from biomimetic 1,4-NADH, 1, to the Zn(II) bound prochiral ketone substrate, followed by a new proton relay, consisting of a water chain connecting His51 to Ser48 that accomplished the S-alkoxy anion's protonation to yield the final S-alcohol product. The HLADH catalysis, with biomimetic co-factor, 1, that replaced the ribose group, the 5'-diphosphate groups, and the adenine nucleotide with a N-benzyl group, has provided a new paradigm for the design of other structures of 1,4-NADH biomimetic co-factors, including their economic value in biocatalysis reactions., (© 2024 The Author(s). ChemBioChem published by Wiley-VCH GmbH.)

Background/purpose: To determine and compare the efficacy of a surgical internal limiting membrane (ILM) flap technique with the traditional ILM peel on long-term visual and anatomical outcomes for large (>400 µm) full-thickness macular holes., Methods: From October 2016 to July 2022, patients undergoing initial full-thickness macular hole repair with the ILM flap or ILM peel technique were reviewed. Final outcomes were recorded and based on size in microns: 401 to 800, 801 to 1,200, and >1,200., Results: Patients treated with ILM flap (n = 52, 94.2% closure rate) or ILM peel (n = 407, 93.6% closure rate) were followed with a mean follow-up time of 15.0 ± 10.2 and 20.0 ± 13.4 months, respectively. Success rates for ILM flaps and ILM peels were compared for full-thickness macular holes of 401 to 800 (100%, 95.8%, P = 0.39), 801 to 1,200 (95%, 93%, P = 0.74), and >1,200 (86.7%, 86.7%, P = 1.0) µm. Mean best-recorded logarithm of the minimal angle of resolution visual acuity for ILM flaps and ILM peels, respectively, was 1.02 ± 0.46 and 0.87 ± 0.47 preoperatively, with follow-up acuity of 0.48 ± 0.32 (P < 0.03) and 0.39 ± 0.42 (P < 0.01) at Year 3., Conclusion: Both techniques provide a similar anatomical closure rate and functional improvement in vision. Comparisons should be cautiously made based on difference in preoperative hole size.

A section in the Acta Crystallographica Section C article by Raymond & Girolami [Acta Cryst. (2023), C79, 445-455] stated that the product of the reaction of [(Cp*Rh) 2 (μ-OH) 3 ] + (Cp* is 1,2,3,4,5-pentamethylcyclopentadiene) with 1-methylthymine (1-MT) at pH 10 and 60 °C, to synthesize the anionic component [Rh I (η 1 -N 3 -1-MT) 2 ] - , was not an Rh I complex, but rather an Ag I complex, due to the use of silver triflate (AgOTf) to remove Cl - from [Cp*RhCl 2 ] 2 to synthesize [Cp*Rh(H 2 O) 3 ](OTf) 2 , a water-soluble crystalline complex. We will clearly show that this premise, as stated, is invalid, while the authors have simply avoided several important facts, including that Cp*OH, a reductive elimination product, at pH 10 and 60 °C, was unequivocally identified, thus leading to the Rh I anionic component [Rh I (η 1 -N 3 -1-MT) 2 ] - . More importantly, AgOH, from the reaction of NaOH at pH 10 with any potentially remaining AgOTf, after the AgCl was filtered off, would be insoluble in water. Furthermore, a control experiment with the inorganic complex Rh(OH) 3 , reacting with 1-methylthymine at pH 10, provided no product, and this bodes well for a similar fate with AgOTf and 1-methylthymine, i.e. at pH 10, AgOTf would again be converted to the water-insoluble AgOH; therefore, no reaction would occur! Finally, a 1 H NMR spectroscopy experiment was carried out with synthesized and crystallized [Cp*Rh(H 2 O) 3 ](OTf) 2 in D 2 O at various pD values; at pD 8.65 no reaction took place, while at pD 13.6, and at 60 °C for 2 h, a reductive elimination reaction caused the precipitation of Cp*OH. The subsequent 1 H NMR spectrum clearly demonstrated, in the absence of any Ag I complexes, that the solution structure and the X-ray crystals in D 2 O were similar. A postulated mechanism for this novel anionic component structure, as published previously [Smith et al. (2014). Organometallics, 33, 2389-2404], will be presented, along with the experimental data, to insure the credibility of our results. We will also answer the comments in the response of Drs Raymond and Girolami to this rebuttal.

Historically marginalized populations are disproportionately affected by many diseases that commonly affect the retina, yet they have been traditionally underrepresented in prospective clinical trials. This study explores whether this disparity affects the clinical trial enrollment process in the retina field and aims to inform future trial recruitment and enrollment. Age, gender, race, ethnicity, preferred language, insurance status, social security number (SSN) status, and median household income (estimated using street address and zip code) for patients referred to at least one prospective, retina-focused clinical trial at a large, urban, retina-based practice were retrospectively extracted using electronic medical records. Data were collected for the 12-month period from 1 January 2022, through 31 December 2022. Recruitment status was categorized as Enrolled, Declined, Communication (defined as patients who were not contacted, were contacted with no response, were waiting for a follow-up, or were scheduled for screening following a clinical trial referral.), and Did Not Qualify (DNQ). Univariable and multivariable analyses were used to determine significant relationships between the Enrolled and Declined groups. Among the 1477 patients, the mean age was 68.5 years old, 647 (43.9%) were male, 900 (61.7%) were White, 139 (9.5%) were Black, and 275 (18.7%) were Hispanic. The distribution of recruitment status was: 635 (43.0%) Enrolled, 232 (15.7%) Declined, 290 (19.6%) Communication, and 320 (21.7%) DNQ. In comparing socioeconomic factors between the Enrolled and Declined groups, significant odds ratios were observed for age ( p < 0.02, odds ratio (OR) = 0.98, 95% confidence interval (CI) [0.97, 1.00]), and between patients who preferred English versus Spanish ( p = 0.004, OR = 0.35, 95% CI [0.17, 0.72]. Significant differences between the Enrolled and Declined groups were also observed for age ( p < 0.05), ethnicity ( p = 0.01), preferred language ( p < 0.05), insurance status ( p = 0.001), and SSN status ( p < 0.001). These factors may contribute to patient participation in retina-focused clinical trials. An awareness of these demographic and socioeconomic disparities may be valuable to consider when attempting to make clinical trial enrollment an equitable process for all patients, and strategies may be useful to help address these challenges.

Purpose: To determine the proportion of patients with proliferative diabetic retinopathy (PDR) who were counted as loss to follow-up (LTFU) patients and to investigate predictive factors., Design: Retrospective cohort study., Methods: Information was collected for 4,423 patients with PDR between April 30, 2012, and April 30, 2017. Two definitions of LTFU were used. Complete LTFU referred to the population who never returned to care within the study period. Interval LTFU referred to the population who did not adhere to clinical recommendations and missed scheduled appointments, resulting in intervals longer than 6 months or 1 year between 2 appointments. Age, average gross income, and insurance were assessed as potential predictors of interval LTFU., Results: Among 4,423 patients with PDR, 2,407 (54.4%) and 2,320 (52.4%) were complete LTFU at 6 months and 1 year, respectively; 782 (17.7%) and 468 (10.6%) patients were interval LTFU for 6 months and 1 year, respectively. Age and average gross income were not found to be significant predictors of interval LTFU. Compared to self-pay, government and private insurance patients were more likely to be interval LTFU at 6 months (government, P = .035; private, P = .005). Private insurance patients were also more likely to be interval LTFU at 1 year (P = .003)., Conclusions: The identified complete LTFU rates were notably high and warrant further study. More than 1 of 6 patients were interval LTFU for at least 6 months, and 1 of 10 patients was interval LTFU for more than 1 year. Insurance status was significant in determining interval LTFU status. Consistent with other analyses, these results indicate that compliance with clinical appointments among patients with PDR is a substantial clinical challenge., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: To determine the rate of postintravitreal injection endophthalmitis and to assess microbiological features and outcomes with and without the use of peri-intravitreal injection topical ophthalmic antibiotics., Methods: Consecutive series of endophthalmitis cases retrospectively identified after intravitreal injection at a multicenter, retina-only referral practice (Retina Consultants of Houston) from January 1, 2011 to December 31, 2014. Prophylactic peri-intravitreal injection topical antibiotics were routinely used during the initial 12-month period (January 1, 2011-December 31, 2011) and not used in the final 24-month period (January 1, 2013-December 31, 2014). Main outcome measures were incidence of endophthalmitis, microbiology results, treatment strategies, and visual outcomes., Results: Of 90,339 intravitreal injections, 30 cases of endophthalmitis were identified (endophthalmitis rate = 0.033%; 95% confidence interval, 0.021-0.045%; or approximately 1 of 3,011 intravitreal injections). The most common organisms isolated were coagulase-negative staphylococci (n = 10, 33%), followed by Streptococcus mitis (n = 2, 7%). Fourteen cases (47%) were culture negative. Peri-intravitreal injection topical antibiotic prophylaxis did not decrease the rate of endophthalmitis (0.035% [95% CI, 0.007-0.064%] with antibiotic use versus 0.021% [95% CI, 0.008-0.033%] without antibiotic use; P = 0.261)., Conclusion: The risk of endophthalmitis after intravitreal injection remains low, with coagulase-negative staphylococci and Streptococcus mitis the most common bacterial isolates identified. Prophylactic peri-intravitreal injection topical ophthalmic antibiotic use did not decrease the endophthalmitis rate.

Purpose: To report macular photic trauma after accidental occupational exposure to a 750-nm Alexandrite laser and management of secondary choroidal neovascularization., Methods: Institutional review board-approved retrospective case report., Results: A 30-year-old woman presented with immediate vision loss in her left eye after direct inadvertent exposure to a single discharge from an occupational 750-nm Alexandrite laser used for laser hair removal. Baseline Snellen visual acuity was 20/40 in the involved left eye. One week after the initial exposure, the patient experienced subjective visual decline to 20/50, was treated with oral prednisone, and then developed a subretinal hemorrhage (SRH) in the setting of choroidal neovascularization 2 weeks later, or 3 weeks after initial trauma. The patient subsequently received 5 intravitreal ranibizumab injections over 25 weeks with resolution of the SRH. Final visual acuity was 20/50., Conclusion: The present case documents development and management of subretinal hemorrhage associated with choroidal neovascularization following macular photic trauma after accidental occupational to a 750-nm Alexandrite laser.

The bioconjugation of organometallic complexes with peptides has proven to be a novel approach for drug discovery. We report the facile and chemoselective reaction of tyrosine-containing G-protein-coupled receptor (GPCR) peptides with [Cp*Rh(H(2)O)(3)](OTf)(2), in water, at room temperature, and at pH 5-6. We have focused on three important GPCR peptides; namely, [Tyr(1)]-leu-enkephalin, [Tyr(4)]-neurotensin(8-13), and [Tyr(3)]-octreotide, each of which has a different position for the tyrosine residue, together with competing functionalities. Importantly, all other functional groups present, i.e., amino, carboxyl, disulfide, phenyl, and indole, were not prominent sites of reactivity by the Cp*Rh tris aqua complex. Furthermore, the influence of the Cp*Rh moiety on the structure of [Tyr(3)]-octreotide was characterized by 2D NMR, resulting in the first representative structure of an organometallic-peptide complex. The biological consequences of these Cp*Rh-peptide complexes, with respect to GPCR binding and growth inhibition of MCF7 and HT29 cancer cells, will be presented for [(η(6)-Cp*Rh-Tyr(1))-leu-enkephalin](OTf)(2) and [(η(6)-Cp*Rh-Tyr(3))-octreotide](OTf)(2).

Fluorous derivatives of dibenzo-18-crown-6 ether were prepared, and then successfully applied in representative solid-liquid phase transfer catalysis reactions, which were performed in standard organic solvents, such as chlorobenzene and toluene, as well as in fluorous solvents, such as perfluoro-1,3-dimethylcyclohexane. It was clearly shown that properly designed fluoroponytailed crown ethers could promote the disintegration of the crystal lattice of alkali salts, and transfer anions from the solid surface into an apolar, non-coordinating perfluorocarbon phase, for phase transfer catalysis reactions in organic synthesis. Furthermore, 3,5-bis(perfluorooctyl)benzyl bromide and triethylamine were reacted under mild conditions to provide an analogue of the versatile phase transfer catalyst, benzyltriethylammonium chloride, containing two fluoroponytails. This fluoroponytailed quaternary ammonium salt was also successfully employed as a catalyst in a variety of organic reactions conducted under solid-liquid phase transfer catalysis conditions, without a perfluorocarbon phase. Thus, being both hydrophobic and lipophobic, fluorous crown ethers and ammonium salts, could be rapidly recovered in quantitative yields, and reused without loss of activity, over several reaction cycles.

The reactions of the breast cancer drug metabolite derivatives of tamoxifen, cis and trans-hydroxytamoxifen, cis-1 and trans-2, with [Cp*Rh(L)(3)](2+) complexes (L = H(2)O or MeOH), in CH(2)Cl(2) and CH(3)OH solvents, initially provided the kinetic η(1)-N complexes, cis-4 (OTf(-), CH(3)OH) and trans-5 (OTf(-), CH(3)OH), which underwent a novel, regioselective, intramolecular N-π rearrangement to give the cis and trans-η(6)-phenol substituted complexes, cis-6 and trans-7, via η(2)-N,O, η(1)-O, and ether aromatic ring η(6) intermediates. Recent density functional theory (DFT) calculations showed a preferred ground state for η(1)-N; η(2)-N,O; η(1)-O; and the η(6) complexes, including the prominent roles of the triflate anion (OTf(-)), and solvent molecules (CH(2)Cl(2) and CH(3)OH), and provided further steric, electronic, and thermodynamic data on the mechanism of the N-π rearrangement. The η(6) complex, cis-6, was shown to be an antagonist for ERα estrogen receptor binding, in a competition experiment with the female hormone, estradiol; therefore, computer docking studies of this biologically active complex at the estrogen receptors, ERα and ERβ, also provided information on the binding modes and thermodynamic parameters, while bioassay results provided growth inhibition data on both hormone dependent and independent breast cancer cell lines.

Purpose: The purpose of this study is to determine the efficacy of combining topical nepafenac with monthly intravitreal injections of ranibizumab or bevacizumab in the treatment of recalcitrant exudative macular degeneration., Methods: This was a retrospective, consecutive case series of patients with exudative macular degeneration requiring maintenance therapy of antivascular endothelial growth factor ( anti-VEGF) injections at least every 6 weeks, who were started on topical nepafenac. Despite frequent anti-VEGF dosing, all patients included in the study had persistence of any combination of the following: intraretinal cysts, subretinal fluid, and/or pigment epithelial detachment. Patients underwent pinhole visual acuity, clinical exam, and optical coherence tomography (OCT) at baseline and every follow-up visit. Response to therapy was graded by reviewing quantitative and qualitative OCT data, and statistical analysis was done with paired Student's t-test., Results: Twenty-five patients (average age 77; 14 male and 11 female) were reviewed; the mean number of previous injections was 17.4 (range 3-31). Baseline mean visual acuity was 20/55, and final mean visual acuity after 3 months of treatment was 20/51 (P = 0.13). Monthly mean central foveal thickness measurements were 248, 250, 257, and 247 μm (P = 0.53) at baseline, 1, 2, and 3 months, respectively. By the end of the 3-month time point, qualitative OCT findings on 13 patients treated with nepafenac were classified as stable, 10 as better, and 2 as worse., Conclusions: There was no significant change in visual acuity or quantitative OCT measurements, but there appeared to be a mild trend toward improved anatomy and qualitative OCT findings when topical nepafenac was added to monthly anti-VEGF injections in patients with persistent intraretinal cysts, subretinal fluid, and/or pigment epithelial detachment. Further prospective studies with longer follow-up may be warranted.

Purpose: While the long-term incidence of hydroxychloroquine (HCQ) retinopathy is low, there remains no definitive clinical screening test to recognize HCQ toxicity before ophthalmoscopic fundus changes or visual symptoms. Patients receiving HCQ were evaluated with spectral domain optical coherence tomography (SD OCT) to assess the feasibility of identifying HCQ retinopathy at an early stage., Methods: Twenty-five patients referred for the evaluation of hydroxychloroquine toxicity underwent a comprehensive ocular examination, Humphrey visual field (HVF) perimetry, time domain OCT, and SD OCT. Some patients with screening abnormalities also underwent further diagnostic testing at the discretion of the treating providers., Results: Five patients were found to have SD OCT findings corresponding to HCQ toxicity and retinal damage as seen by clinical exam and/or HVF perimetry. Two patients with advanced toxicity were found to have significant outer retina disruption in the macula on SD OCT. Three patients with early HCQ toxicity and HVF 10-2 perifoveal defects were found to have loss of the perifoveal photoreceptor inner segment/outer segment (IS/OS) junction with intact outer retina directly under the fovea, creating the "flying saucer" sign. While two of these three patients had early ophthalmoscopic fundus changes, one had none., Conclusion: Outer retinal abnormalities including perifoveal photoreceptor IS/OS junction disruption can be identified by SD OCT in early HCQ toxicity, sometimes even before ophthalmoscopic fundus changes are apparent. SD OCT may have a potential complementary role in screening for HCQ retinopathy due to its quick acquisition and because it is more objective than automated perimetry.

Purpose: Combination verteporfin photodynamic therapy (vPDT) and antivascular endothelial growth factor (anti-VEGF) therapy may decrease the need for injections while maintaining visual acuity in exudative age-related macular degeneration. This pilot study was designed to determine the threshold fluence dose of vPDT (the dose required to demonstrate an effect on choroidal perfusion) combined with ranibizumab., Methods: Seven patients were randomized to sham vPDT (two patients), 20% fluence vPDT (two patients), or 40% fluence vPDT (three patients) in combination with three-monthly intravitreal 0.5 mg ranibizumab injections. Intravitreal ranibizumab was reinjected if disease activity was seen on fluorescein angiography, optical coherence tomography, or clinical examination. Indocyanine green-determined choroidal hypoperfusion was graded in a masked fashion., Results: Patients with 20% vPDT had mild hypoperfusion defects at seven days that resolved by week 4 (threshold dose); patients with 40% fluence vPDT had marked hypoperfusion at seven days that persisted as long as 12 months. Recruitment was stopped after limited efficacy was observed. One patient with 20% fluence vPDT lost 19 letters at one year; no other patient lost or gained >10 letters. Central retinal thickness decreased in six of seven patients, but ranibizumab injections did not decrease., Conclusion: This pilot study shows that the threshold fluence dose of vPDT (when combined with ranibizumab) is approximately 20% standard fluence, and that mild and transient choroidal hypoperfusion can occur. Forty percent fluence vPDT causes a more prolonged and striking hypoperfusion. Despite hypoperfusion, no decrease in visual acuity or injections required was noted, suggesting that even higher fluence levels of vPDT may be necessary to decrease the number of anti-VEGF injections.

The previously reported reactions of cis and trans-hydroxytamoxifen drug derivatives, 1 and 2, with [Cp*Rh(L)(3)](2+) complexes (L = H(2)O, CH(3)OH), initially provided the kinetically controled eta(1)-N complexes, 4(OTf, CH(3)OH) and 5(OTf, CH(3)OH), which underwent a novel, intramolecular, regioselective N-pi rearrangement to provide the eta(6) complexes, 6 and 7. A dramatic solvent effect was also observed on the rate of this N-pi rearrangement in CH(3)OH or CH(2)Cl(2). Therefore, a DFT study was conducted that provided further mechanistic and thermodynamic data on this N-pi rearrangement. The preferred structures of both the eta(1)-N and eta(6) complexes in the two solvents were determined, and a thorough analysis of their geometries and electronic structures has been provided. The influence of the solvent on the N-pi rearrangement was studied by including the solvent both implicitly using a PCM model, and explicitly by introducing the counterion and/or the solvent molecules into the inner and outer coordination spheres of the complexes. It was shown that the triflate (OTf(-)) counterion was strongly bound in the inner coordination sphere of the eta(1)-N complexes, 4(OTf) and 5(OTf), and in the outer sphere of the coordinatively saturated eta(6) complexes, 6 and 7, especially in non-polar media. The cleavage of the ionic Cp*Rh-OTf bond was found to be the rate-limiting step in the N-pi rearrangement. The thermodynamic results suggested that the eta(6) complexes were more stable than the eta(1)-N complexes in CH(2)Cl(2) and in CH(3)OH at elevated temperatures. The opposite relationship for the stabilities of the eta(1)-N complexes was found in CH(3)OH at room temperature, thus corroborating the experimental results that the N-pi rearrangement did not occur, under these conditions. A plausible mechanistic pathway for the N-pi rearrangement was proposed from our extensive DFT studies, that included several important intermediates and transition states, and provided a unique view of this novel transformation.

The authors report four cases where spectral domain optical coherence tomography (SD-OCT) imaged pathology not captured by time domain optical coherence tomography (TD-OCT). These cases include one of angioid streaks, two of juxtafoveal telangiectasia, and one of age-related macular degeneration. In each case, the improved images provided by SD-OCT changed either the management of the patient or the counseling of their disease process.

The reactions of arene-metal complexes (arene=p-cymene, benzene or pentamethylcyclopentadienyl, metal=Ru, Rh or Os), including 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decanephosphine (pta) and chloro co-ligands, with 9-methylguanine, adenine, and a series of nucleosides were studied in water to ascertain the binding modes. The products were characterized by NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). Tandem mass spectrometry was found to provide excellent information on preferential binding sites. In general, the N7 position on guanine (the most basic site) was found to be the preferred donor atom for coordination to the metal complexes. The X-ray structures of the precursor complexes, [(eta5-C10H15)RhCl(pta-Me)2]Cl2, [(eta6-C10H14)OsCl(pta)2]Cl, and [(eta6-C6H6)OsCl2(CH3CN)], are also reported.

Purpose: The historical extrusion/explantation rate of silicone sponge scleral buckle exoplants is 3.5 to 24.4%. This contrasts with the published 0.6 to 1.2% explantation rate of solid silicone elements. Previously reported silicone sponge exoplants studies were noncircumferential (quadrantic or multiple). This study was undertaken to assess the long-term stability of 360 degrees circumferentially placed 3 x 5 mm silicone sponge exoplants., Methods: Interventional case series of 840 consecutive circumferentially placed 3 x 5 mm silicone sponge exoplants. A retrospective review of operative reports and patient charts was performed., Results: A total of 552 patients had documented follow-up over 1 year. Median follow-up was 32.8 months. Six patients underwent removal of the scleral buckling element (two for diplopia, one acute postoperative infection, and three for extrusion). Median time to removal was 7.3 months. Extenuating circumstances contributed to two of the three extrusions. Of the entire series, fewer than 1% of patients required removal of the silicone sponge implant. Excluding patients with less than 1 year of documented follow-up, the long-term infection/extrusion rate was 0.7%., Conclusions: Circumferentially placed silicone scleral buckling sponge elements are very stable and are well tolerated. The explantation/extrusion rate is comparable to published solid silicone element series.

This fluorous biphasic catalysis (FBC) contribution was focused on the synthesis and characterization of new fluorous soluble R(f)-Cu(II) carboxylate complexes containing nonfluoroponytailed ligands and defines their role as precatalysts for the FBC oxidation of alkenols and alcohols in the presence of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)/O(2). In this FBC approach, we have utilized the phase-switching technique of Vincent et al. (J. Am. Chem. Soc. 2002, 124, 12942) to solubilize the nonfluoroponytailed ligands, N-1,4,7-Me(3)TACN, 2, and N-1,4,7-pentamethyldiethylenetriamine (PMDETA), 3, by reaction with a fluorous solvent-soluble copper (II) dimeric complex, [Cu({C(8)F(17)(CH(2))(2)}(2)CHCO(2))(2)](2), 1. Moreover, the reaction of nonfluoroponytailed ligands 2 and 3 with 1 afforded new perfluoroheptane-soluble Cu(II) complexes, [Cu({C(8)F(17)(CH(2))(2)}(2)CHCO(2))(2)(2)], 4, and [Cu({C(8)F(17)(CH(2))(2)}(2)CHCO(2))(2) (3)], 5, respectively. The known Cu(II) complex, 1, was further characterized by electron paramagnetic resonance (EPR) spectroscopy confirming its dimeric structure, while 4 and 5 were characterized by elemental analysis, IR, diffuse reflectance UV-vis, and EPR spectroscopy. Furthermore, 1, 4, and 5 were evaluated as precatalysts for alkenol and alcohol oxidation. The oxidation reactions of alkenols and alcohols in the presence of TEMPO/O(2) proceeded under FBC conditions for 1, 4, and 5, but 1-octanol was unreactive under single-phase FBC conditions at 90 degrees C with TEMPO/O(2). The thermomorphic property of 5, soluble in chlorobenzene/toluene at 90 degrees C but insoluble at room temperature, was also evaluated in the selective oxidation of p-nitrobenzyl alcohol to p-nitrobenzaldehyde. Plausible mechanisms concerning these FBC/thermomorphic oxidation reactions will be discussed.

[reaction: see text] Polyfluorinated quaternary ammonium cations, [CF(3)(CF(2))(7)(CH(2))(3)](3)CH(3)N(+) (R(F)N(+)), were synthesized and used as countercations for the [WZnM(2)(H(2)O)(2)(ZnW(9)O(34))(2)](12)(-) (M = Mn(II), Zn(II)) polyoxometalate. The (R(F)N(+))(12)[WZnM(2)(H(2)O)(2)(ZnW(9)O(34))(2)] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected by both the hydrophobicity of the solvent and the substrate.

In this contribution on fluorous biphasic catalysis (FBC), we present the synthesis and characterization of new copper complexes, and define their role, as precatalysts, in the FBC oxidation of hydrocarbons, olefins, and alcohols. Thus the previously reported, but poorly characterized, fluoroponytailed ligand, 2,2'-R(f)-bipyridine (R(f)=-(CH(2))(3)C(8)F(17)) 2, as well as the new Cu(II) fluoroponytailed carboxylate synthon complex [Cu(C(8)F(17)(CH(2))(2)CO(2))(2)] 3, will be addressed. Moreover, the reaction of previously described ligands, 1,4,7-R(f)-TACN 1, or 2,2'-R(f)-bipyridine 2 with 3 afforded new perfluoroheptane-soluble Cu(II) complexes, [Cu(C(8)F(17)(CH(2))(2)CO(2))(2)(R(f)-tacn)] 4 and [Cu(C(8)F(17)(CH(2))(2)CO(2))(2)(R(f)-bpy)] 5, respectively. The reaction of 1 with [Cu(CH(3)CN)(4)]PF(6) or [CuCl] provided new Cu(I) complexes, which could be isolated and fully characterized as [Cu(R(f)-tacn)X']X, in which X=PF(6) (6) or X'=Cl (7) (soluble in perfluoroheptane). The Cu(II) and Cu(I) complexes, 4-7, were characterized by elemental analysis, mass spectrometry, and IR, diffuse reflectance UV/Vis, and EPR spectroscopies; complex 7 was also characterized by (1)H and (19)F[(1)H] NMR spectroscopy. Complexes 4 and 5, as well as 6 and 7 generated in situ, were evaluated as precatalysts for hydrocarbon and olefin functionalization. The oxidation reactions of these substrates in the presence of the necessary oxidants, tert-butyl hydroperoxide (TBHP) and oxygen gas, proceeded under FBC conditions for 5, 7, and Cu(I) salts with 2. However, the complexes with ligand 2 could not be recycled, owing to significant ligand dissociation. The Cu(II) complex 4, with the ligand 1, provide the oxidation of 4-nitrobenzyl alcohol to 4-nitrobenzaldehyde under single-phase FBC conditions at 90 degrees C with TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxy) and O(2); the precatalyst 4, can be utilized for an additional four catalytic cycles without loss of activity. Plausible mechanisms concerning these FBC oxidation reactions will be discussed.

Cofactor regeneration; i.e., regiospecific conversion of NAD(+) to 1,4-NADH, has been extensively studied and is a crucial component in the eventual use of 1,4-NADH in a variety of bioorganic synthesis processes involving the formation of chiral organic compounds. We have studied the reduction of a model NAD(+) compound, 1-benzylnicotinamide triflate, 1a, using [CpRh(bpy)(H(2)O)](2+), 2 (Cp = eta(5)-C(5)Me(5), bpy = 2,2'-bipyridyl), as the catalyst precursor and sodium formate (HCO(2)Na) as the hydride source in 1:1 H(2)O/THF and have found exclusive 1-benzyl-1,4-dihydronicotinamide regioselectivity, as was observed previously for natural NAD(+) that provided 1,4-NADH (see: Steckhan et al. Organometallics 1991, 10, 1568). Moreover, a variety of 3-substituted derivatives of 1-benzylpyridinium triflate, in addition to the -C(O)NH(2) group (1a), were also studied to ascertain that this 3-functionality (e.g., -C(O)NHCH(3), -C(S)NH(2), -C(O)CH(3), -C(O)OCH(3), and -CN, 1b,d-g) coordinates to a [CpRh(bpy)H](+) complex to direct the concerted, regioselective transfer of the hydride group from the rhodium to the 4-ring position of the NAD(+) model; all coordinating 3-substituents had relative rates in the 0.9-1.3 range with substrate 1a set to 1.0. If in fact the 3-substituent presented a steric effect [-C(O)NH(CH(2)CH(3))(2), 1c] or was a nonbinding group (-CH(3), 1h; -H, 1i), no catalytic hydride transfer was observed even with the more electrophilic 2 and 6 ring positions being readily available, which further implicated the crucial coordination of the NAD(+) model to the CpRh metal ion center. We also found that the 1-benzyl substituent on the nitrogen atom exerted a substantial electron-withdrawing effect, in comparison to the electron-donating 1-methyl substituent, and favorably affected the rate of the regioselective reduction (rate enhancement of 1-benzyl/1-methyl = 2.0). The kinetics of the regioselective reduction of 1a were studied to show that the initial rate of reduction, r(i), is affected by the concentrations of the substrate, 1a, precatalyst, 2, and the hydride source, HCO(2)Na, in 1:1 H(2)O/THF: d[1-benzyl-1,4-dihydronicotnamide]/dt = k(cat)[1a][2][HCO(2)Na]. Furthermore, we wish to demonstrate that a previously synthesized aqueous NAD(+) model, beta-nicotinamide ribose-5'-methyl phosphate, 3, shows a similar regioselectivity for the 1,4-NADH analogue, while the initial rate (r(i)) for the regioselective reduction of 3 and NAD(+) itself was found to be comparable in water but faster by a factor of approximately 3 in comparison to 1a in 1:1 H(2)O/THF; the solvent, THF, appeared to inhibit the rate of reduction in 1a by presumably competing with the substrate 1a for the CpRh metal ion center. However, in H(2)O, the initial kinetic rate for substrate 3 was not affected by its concentration and implies that, in H(2)O, [CpRh(bpy)H](+) formation is rate determining. We assume that binding of 3 and NAD(+) to the CpRh metal ion center is also a pertinent step for 1,4-dihydro product formation, the experimental rate expression in H(2)O being d[1,4-dihydro-beta-nicotinamide ribose-5'-methyl phosphate]/dt = k(cat)[2][HCO(2)Na]. What we have discovered, for the first time, is evidence that the regioselective reduction of NAD(+) to 1,4-NADH by [CpRh(bpy)H](+) is a consequence of the amide's ability to coordinate to the CpRh metal center, thereby constricting the kinetically favorable six-membered ring transition state for plausible concerted hydride transfer/insertion to C4 to regioselectively provide the 1,4-NADH derivative; [CpRh(bpy)H](+) can be categorized as a biomimetic enzymatic hydride via its ability to bind and regioselectively transfer hydride to C4, exclusively. Clearly, the pyrophosphate and adenosine groups associated with the structure of NAD(+) are not essential in the rate of hydride transfer to C4, with NAD(+) model 3 having a similar initial rate (r(i)) of reduction as NAD(+) itself in water. Finally, a catalytic cycle will be proposed to account for our overall observations.

The biomimetic, methane monooxygenase enzyme (MMO) precatalyst, [Fe(2)O(eta(1)-H(2)O)(eta(1)-OAc)(TPA)(2)](3+) (TPA = tris[(2-pyridyl)methyl]amine), 1, formed in situ at pH 4.2 from [Fe(2)O(&mgr;-OAc)(TPA)(2)](3+), 2, was embedded in an amorphous silicate surface modified by a combination of hydrophilic poly(ethylene oxide) and hydrophobic poly(propylene oxide). The resulting catalytic assembly was found to be a biomimetic model for the MMO active site within a hydrophobic macroenvironment, allowing alkane functionalization with tert-butyl hydroperoxide (TBHP)/O(2) in an aqueous reaction medium (pH 4.2). For example, cyclohexane was oxidized to a mixture of cyclohexanone, cyclohexanol, and cyclohexyl-tert-butyl peroxide, in a ratio of approximately 3:1:2. The balance between poly(ethylene oxide) and poly(propylene oxide), tethered on the silica surface, was crucial for maximizing the catalytic activity. The silica-based catalytic assembly showed reactivity somewhat higher in comparison to an aqueous micelle system utilizing the surfactant, cetyltrimethylammonium hydrogen sulfate at its critical micelle concentration, in which functionalization of cyclohexane with TBHP/O(2) in the presence of 1 was also studied at pH 4.2 and was found to provide similar products: cyclohexanol, cyclohexanone, and cyclohexyl-tert-butyl peroxide, in a ratio of approximately 2:3:1. Moreover, the mechanism for both the silica-based catalytic assembly and the aqueous micelle system was found to occur via the Haber-Weiss process, in which redox chemistry between 1 and TBHP provides both the t-BuO(*)() and t-BuOO(*)()( )()radicals. The t-BuO(*)()( )()radical initiates the C-H functionalization reaction to form the carbon radical, followed by O(2) trapping, to provide cyclohexyl hydroperoxide, which produces the cyclohexanol and cyclohexanone in the presence of 1, whereas the coupling product emanates from t-BuOO(*)() and cyclohexyl radicals. A discussion concerning both approaches for alkane functionalization in water will be presented.

The hydride transfer mechanism of the NAD + model compound 1 to its 1,4-NADH derivative 3 [Eq. (1)] is proposed to be a consequence of the critical role of the carbonyl group of the amide to coordinate to the ring-slipped η 5 - to η 3 -Cp*Rh metal center of the catalyst [Cp*Rh(bpy)H] + , prepared in situ from 2, while a steric effect of a substituent in the 3 position, for example, C(O)NEt 2 , was found to totally inhibit this regioselective reduction. bpy=2,2'-bipyridine, Cp*=C 5 Me 5 , OTf=trifluoromethanesulfanate., (© 1999 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.)

We have discovered that the supramolecular host [CpRh(2'-deoxyadenosine)](3)(OTf)(3) (1, Cp = eta(5)-C(5)Me(5), OTf = CF(3)SO(3)(-)) has utility as a new, aqueous (1)H NMR shift reagent, via a host-guest molecular recognition process that occurs by non-covalent pi-pi and hydrophobic interactions, with a wide variety of H(2)O-soluble organic substrates. These organic compound guests that we present, to illustrate the utility of host 1 as a novel, aqueous (1)H NMR shift reagent, encompass examples such as aromatic carboxylic acids, phenylacetic acid (G1), 1-naphthoic acid (G2), and 2-naphthoic acid (G3), an aliphatic carboxylic acid, cyclohexylacetic acid (G4), as well as biological compounds, a di- and a tetrapeptide containing terminal L-tryptophan (Trp) or L-phenylalanine (Phe) groups, L-Trp-L-Phe (G5) and L-Trp-L-Met-L-Asp-L-Phe amide (G6) in the pH range 5-10. A discussion of the molecular recognition parameters that effect the (1)H NMR shifts of the organic guests and a comparison with the water-soluble lanthanide shift reagents (LSRs) will be presented to demonstrate the usefulness of this aqueous molecular receptor as an aid for organic compound structural analysis.

The synthetic reactions of quinaldic acid (2-QA, 1), a ligand with potential implications in Al(3+) ion biological transport and in pharmaceutical applications and of use for the removal and recovery of Al(3+) ions from environmental waste sites, were studied with tri- and divalent metal ions that encompass Al(3+), Fe(3+), Ga(3+), Zn(2+), Ni(2+), Mn(2+), and Co(2+). The Al(3+), Fe(3+), and Ga(3+) metal ion complexes, 2-4, of 1 were characterized by FT-IR, FAB/MS, NMR, and elemental analysis and provided the following structural formula with 1 of 2-QA(4)M(2)(&mgr;-OH)(2).S, where S = H(2)O or pyridine. In the case of the Ga(3+ )analog, 4.Py, the unequivocal &mgr;-OH dimer structure was determined by single-crystal X-ray analysis [space group, P1; a = 13.387(3) Å; b = 14.016(2) Å; c = 14.549(2) Å; alpha = 87.74(2) degrees; beta = 73.44(2) degrees; gamma = 82.61(2) degrees; Z = 2; volume = 2592.6 Å(3)]. A description of the X-ray crystal structure of 2-QA(4)Ga(2)(&mgr;-OH)(2).4 pyridine, 4.Py, will also be presented. The corresponding bis(2-QA) metal complexes of Zn(2+), Ni(2+), Mn(2+), and Co(2+), 5-8, were also studied and all provided a formula of 2-QA(2)M.1.5 H(2)O, which were also characterized by many of the above-mentioned spectroscopic techniques. The polymer-supported (PS) version of 1, PS-2-QA, bonded to modified, macroporous 6% cross-linked polystyrene-divinylbenzene beads, was synthesized by an electrophilic substitution reaction on the aromatic ring of a 2-QA derivative, ethyl 2-quinaldate, with the chloromethylated precursor, PS-CH(2)Cl, followed by subsequent ester hydroysis to the free PS-2-QA ligand. The PS-2-QA ligand was found to selectively remove Al(3+) ions from aqueous acidic solution (pH = 3-5) in the presence of other divalent metal ions, namely, Cu(2+), Zn(2+), Ni(2+), Mn(2+), and Co(2+) as well as a trivalent metal ion, Cr(3+).

Background: Neuroretinitis is a distinct clinical entity consisting of moderate to severe visual loss, optic nerve head edema, macular exudate in a stellate pattern, and variable vitreous inflammation. Although the etiology is usually postviral or idiopathic, an acute infectious cause occasionally is demonstrated., Methods: Five juvenile or young adult patients with neuroretinitis are presented with serologic evidence of Toxoplasma gondii infection. Four of the five patients were treated with systemic antibiotics and corticosteroids; one patient was not treated., Results: With a mean follow-up period of 50 months, visual acuity returned to 20/25 or better in four patients, with one patient regaining visual acuity of 20/60. Two patients had one or more recurrent episodes of neuroretinitis, distinguishing toxoplasmosis from idiopathic neuroretinitis, which is usually a monophasic illness., Conclusion: Toxoplasmosis infection is a rare, but potentially treatable, form of neuroretinitis and should be included in the differential diagnosis of "Leber's idiopathic stellate retinopathy."

Background: An experimental sustained release intraocular device has been designed to deliver ganciclovir over a long period of time. As part of an efficacy trial, the ganciclovir intraocular device was used to treat cytomegalovirus (CMV) retinitis in patients with acquired immune deficiency syndrome (AIDS)., Methods: All patients had active CMV retinitis that had progressed despite intravenous ganciclovir therapy. The ganciclovir intraocular device was inserted into the vitreous cavity by making an inferotemporal full-thickness circumferential sclerotomy and anchored to the incision. Intravenous therapy was then discontinued and patients were followed up at 2-week intervals until death. Seven eyes from five patients were obtained 2 to 10 hours postmortem and submitted for histopathologic examination. Light and electron microscopic studies were performed and correlated to the clinical outcome. Follow-up period after device placement ranged from 16 to 82 days (median, 70 days)., Results: All seven eyes showed clinical stabilization of the CMV retinitis. Light microscopy showed varying degrees of retinal atrophy with areas of gliosis. In addition, we observed syncytial megalic cells containing Cowdrey type A inclusions affecting all layers of the retina. Concurrent choroidal infections with Pneumocystis carinii (1) and Mycobacterium avium (2) also were seen. Electron microscopy showed virus particles located mostly at the junction of uninvolved and "healed" retinitis. No evidence of retinal toxic effects or inflammation at the site of ganciclovir intraocular device implant was noted., Conclusion: The ganciclovir intraocular device appeared to be effective in controlling the progression of CMV retinitis. The clinical and pathologic results are similar to those observed in the eyes of patients with intravenously administered ganciclovir. The lack of toxic effects and sustained levels of intravitreal ganciclovir may provide an improved therapeutic method of local treatment of CMV retinitis.

An experimental intravitreal sustained-release device containing ganciclovir was used to treat 22 patients with acquired immunodeficiency syndrome-associated cytomegalovirus retinitis. Fourteen eyes were excluded (five not involved and nine with macular scarring and/or severe debility). Thirty eyes received the ganciclovir intraocular device implant and were prospectively followed up from 16 to 419 days (median, 125 days). Twenty-seven (90%) of 30 eyes showed stabilization of the retinitis. Nine (33%) of 27 eyes showed reactivation of the retinitis once the device was empty of ganciclovir; seven received a replacement device, with subsequent stabilization of the retinitis. Postoperative complications included vitreous hemorrhage (n = 1), endophthalmitis (n = 1), and progressive retinitis (n = 2). Late retinal detachment was seen in three eyes (11%) at 35 to 140 days. Survival analysis of all 30 eyes revealed the mean time to progression of retinitis to be 19 weeks (133 days). The ganciclovir intraocular device offers a promising alternative for the treatment of cytomegalovirus retinitis associated with acquired immunodeficiency syndrome.

Unilateral acute idiopathic maculopathy (UAIM) is a recently described condition in young adults consisting of rapidly progressive central visual loss, gray-white opacification of the outer retina, and serous detachment of the macula. Bull's eye pattern pigmentary changes may occur in the macula after resolution of the acute phase of the disease. A case of UAIM in which a shifting of subretinal inflammatory infiltrate was observed is reported. This is the tenth reported case of UAIM, and represents a variation in the clinical presentation of this disease. The appearance and the shifting of the subretinal infiltrate seen in this patient support an inflammatory etiology of UAIM.

Background: Epimacular membrane with pseudohole is an important vitreomacular disorder that belongs in the differential diagnosis of impending and established macular hole. To better characterize this lesion, the authors attempted to identify various features of eyes with epimacular membrane and pseudohole., Methods: Demographic, clinical, photographic, and fluorescein angiographic data for 14 eyes with epimacular membrane and pseudohole were reviewed. Horizontal and vertical diameters of the pseudoholes were measured, and the original diagnosis was recorded for each eye. Fluorescein angiography was performed in 11 eyes., Results: The mean age of patients with macular pseudoholes was 61.6 years, and median visual acuity for pseudohole eyes was 20/30. Mean horizontal and vertical diameters of the pseudoholes were 384 and 410 microns, respectively. None of the eyes with pseudoholes had the characteristic ophthalmoscopic features associated with full-thickness macular holes or impending macular holes. Results of fluorescein angiography showed three eyes with increased tortuosity or abnormal straightening of the perifoveal vessels; three eyes with a foveal window defect; and three eyes with late leakage from the perifoveal vessels. The original diagnosis of the initial examining physician was correct in only 43% of eyes with epimacular membrane and pseudohole., Conclusion: Epimacular membrane with pseudohole may be an underdiagnosed lesion and commonly mistaken for impending macular hole, full-thickness hole, or lamellar hole. These data may be of use as more patients are being considered for recently advocated surgical treatments for impending and established macular hole.

Acute frosted retinal periphlebitis is an inflammatory condition of unknown origin characterized by marked perivenular infiltration in otherwise healthy patients. We encountered seven patients with acquired immunodeficiency syndrome who exhibited visual loss associated with an unusual diffuse retinal periphlebitis very similar in appearance to acute frosted retinal periphlebitis. Each patient developed a thick inflammatory infiltrate surrounding the retinal venules, creating a frosted appearance. Two cases were bilateral. All patients had areas of more typical cytomegalovirus retinitis in their involved eye(s). Five of six patients treated with ganciclovir sodium showed improvement not only of the cytomegalovirus retinitis but also of the periphlebitis. Although we do not have histopathologic evidence that cytomegalovirus was the cause of these cases of periphlebitis, we believe that periphlebitis may be a previously unrecognized finding of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome. So far, there is no evidence implicating cytomegalovirus as the cause of acute frosted retinal periphlebitis in healthy patients.

The enantiomeric composition of the pheromone components (+)-ipsdienoI, e.e. 87.6%, and (-)-ipsenol, e.e. 93.8%, produced by the male bark beetleIps paraconfusus (Scolytidae) under natural conditions was determined by HPLC separation of their diastereomeric ester derivatives. Males confined in an atmosphere of ipsdienone produced (-)-ipsdienol, e.e. 28%, and (-)-ipsenol, e.e. 86%, indicating an enantiomeric selectivity in the conversion of the ketone to the alcohols. These findings demonstrate an enantioselective conversion mechanism in the biosynthetic pathway to the pheromones from myrcene, a host-plant terpene.

The biological oxidation of several tributyltin derivatives, by a cytochrome P-450 dependent monooxygenase enzyme system with reduced nicotinamideadeninedinucleotidephosphate as the essential cofactor, produced carbon-hydroxylated compounds identified as alpha-, beta-, gamma- and delta-hydroxybutyldibutyltin derivatives. The hydroxylation pattern and the lack of oxidative cleavage of tin-carbon bonds strongly suggest a free radical rather than an oxenoid mechanism, while the predominance of beta-carbon-hydroxylation further implies some role of the tin-carbon sigma electrons in directing the site of hydroxylation.