Bony Congenital Nasolacrimal Duct Obstruction: A Novel Phenotype of Aplasia of Lacrimal and Major Salivary Glands

PURPOSE

Aplasia of lacrimal and salivary glands (ALSG) is a syndromic disorder characterized by aplasia of lacrimal and salivary systems. Reported ophthalmic manifestations of ALSG include aplasia of lacrimal glands, punctal agenesis, lacrimal sac mucocele, and membranous congenital nasolacrimal duct obstruction (CNLDO). Bony CNLDO, a rare clinical entity, has not been associated with any syndromic disorder. This study investigated the relationship between genetic mutations and bony CNLDO in 3 Chinese families with ALSG.

DESIGN

Single-center observational case study.

PARTICIPANTS

Three Chinese families with bony CNLDO, including 7 affected and 9 healthy family members.

METHODS

Slit-lamp ophthalmic examination, comprehensive physical examination, orbital computed tomography (CT) imaging, cervicofacial magnetic resonance imaging, audiometry, and whole exome sequencing on periphery blood were performed. Variants were cross-referenced with 1000 control genomes and various population databases. Pathologic variants were identified using bioinformatic tools.

MAIN OUTCOME MEASURES

Clinical examination, diagnostic imaging, whole exome sequencing, and bioinformatic analysis findings.

RESULTS

Affected patients showed decreased tear production on the Schimer I test and reduced tear breakup time. Bony CNLDO was observed on CT, showing unilateral or bilateral bony termination at the middle or terminal segment of the nasolacrimal canal. Magnetic resonance imaging showed aplasia or absence of lacrimal, parotid, and submandibular glands. Physical examination revealed normal ears, digits, and facial morphology. Audiometry and dental assessment were conducted on the pediatric patients and yielded normal results. The clinical characteristics of patients aligned with a diagnosis of ALSG. Genomic analysis revealed 3 novel heterozygous missense mutations of the Fgf10 gene: c.316T→C, c.327C→G, and c.332T→G. The inheritance pattern was autosomal dominant with variable penetrance. These variants were not observed in 1000 control genomes and population databases. These variant positions also were shown to be highly conserved across various animal species. Mutated genes and proteins were predicted as deleterious with most computational models, with a few suggesting they may be benign.

CONCLUSIONS

Bony CNLDO was identified as a novel phenotype of ALSG implicated by missense mutations of highly conserved residues in the Fgf10 gene. These cases broadened our knowledge of Fgf10-related phenotypes and prompted clinicians to consider syndromic associations in patients with bony CNLDO.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Risk of ocular adverse events with aromatase inhibitors

PURPOSE

Aromatase inhibitors (AIs) are a class of medications used for adjuvant treatment of breast cancer. Recent case reports suggest that AIs may be associated with various ocular adverse events (AEs). This study evaluates the risk of ocular AEs in patients who take AIs.

METHOD

Disproportionality analysis was performed using data from the U.S. Food and Drug Administration's Adverse Events Reporting System database from 2004 to 2022. All cases of vitreomacular traction, macular edema, retinal deposits, retinal artery occlusion, macular hole, retinal hemorrhage, uveitis, retinal tear, retinal detachment, dry eye disease, blepharitis, and optic neuropathy were searched for the 3 AIs anastrozole, letrozole, and exemestane. A search also was performed on trastuzumab as a control. Reported odds ratios (RORs) and corresponding 95% CIs were computed.

RESULTS

We identified 322 ocular AEs of interest for the 3 AIs and 55 for trastuzumab. Anastrozole had the most AEs (n = 163) and was found to have strong associations with vitreomacular traction (ROR = 665; 95% CI, 352-1255), macular edema (ROR = 37; 95% CI, 25-54), retinal deposits (ROR = 11; 95% CI, 2-77), and uveitis (ROR = 6; 95% CI, 4-9). Letrozole had strong associations with retinal deposits (ROR = 8, 95% CI, 1-57) and retinal artery occlusion (ROR = 6; 95% CI, 3-11). Exemestane had a strong association with macular holes (ROR = 10; 95% CI, 3-30).

CONCLUSION

Disproportionality analysis revealed an increased risk of ocular AEs with each of the AIs. This study calls for clinicians, especially oncologists and ophthalmologists, to be vigilant in patients who are on AI therapy, allowing them to provide prompt interventions to mitigate further ocular morbidities.

Adjuvant Chemotherapy Improves Survival for Children With Massive Choroidal Invasion of Retinoblastoma

Purpose

The purpose of this study was to investigate the effect of adjuvant chemotherapy on outcomes of children with massive choroidal invasion (MCI).

Methods

In this study, we reviewed the 5-year relapse-free survival (RFS) and overall survival (OS) of children diagnosed with MCI, managed with or without adjuvant chemotherapy. Excluded were children with additional other high-risk features (post-laminar optic nerve invasion, scleral invasion, or overt extraocular disease).

Results

Of 3566 children diagnosed with retinoblastoma, 2023 had enucleation, and 60 eyes of 60 children had pathology showing MCI without concomitant high-risk features. Enucleation was primary (22, 37%), or secondary (38, 63%) after failed eye salvage. Adjuvant systemic chemotherapy (median = 4, range = 1-8 cycles) was given to 48 of 60 (80%) children; 12 of 60 (20%) children had no adjuvant therapy. Five-year RFS was 88.5% (95% confidence interval [CI] = 79.7%-97.3%) and 5-year OS was 90.1% (95% CI = 81.7%-98.5%). Pre-enucleation chemotherapy did not affect RFS (89.7% vs. 75.0%; P = 0.657). Adjuvant chemotherapy improved RFS (97.2% vs. 55.6%; P < 0.001) and OS (97.2% vs. 66.7%; P < 0.001). In subgroup analysis, adjuvant chemotherapy improved RFS for both primarily enucleated (5-year RFS 100% vs. 50.0%; P = 0.002) and secondarily enucleated children (5-year RFS 95.8% vs. 60.0%; P = 0.005). The number of children treated with adjuvant chemotherapy to prevent one post-enucleation systemic relapse or death is three.

Conclusions

Adjuvant chemotherapy significantly decreased the risk of tumor relapse and death for children with pathological MCI. For every three children treated with adjuvant chemotherapy, one systemic relapse or death could be prevented.

Tylectomy Safety in Salvage of Eyes with Retinoblastoma

Simple Summary

The role of organ-conserving surgery has not been explored in retinoblastoma as it has been in other cancers, such as breast cancer lumpectomy, partial nephrectomy for kidney cancer, and partial orchiectomy for testis cancer. This is largely accounted for by the high mortality of extraocular retinoblastoma compared to intraocular retinoblastoma, and fear of iatrogenic tumor spread with intraocular surgery. We propose the little-known word “tylectomy” (“tulos”, Greek for “lump”) to describe the surgical resection of retinoblastoma. Through review of consecutive patients treated by our team between 2012–2014, we compared survival of patients with eye salvage, including tylectomy, to those who had eye salvage without tylectomy or primary enucleation. We found that patients who had tylectomy had superior survival compared to those who had eye salvage without tylectomy (96% vs. 90%), and comparable survival to those with primary enucleation (96% vs. 95%). Our study supports tylectomy as a safe contribution to retinoblastoma management.

Abstract

Intraocular surgery is tabooed in retinoblastoma management, due to the concern of lethal extraocular spread. We reviewed the outcomes of consecutive children with intraocular retinoblastoma diagnosed at 29 Chinese centers between 2012–2014. We compared the outcomes of three categories of treatment: eye salvage including tylectomy (Group I), eye salvage without tylectomy (Group II), and primary enucleation (Group III). A total of 960 patients (1243 eyes) were diagnosed: 256 in Group I, 370 in Group II, and 293 in Group III; 41 patients abandoned treatment upfront. The estimated 5-year overall survivals (OS) were, for Group I, 94%, for Group II 89%, and for Group III 95%. The estimated 5-year disease-specific survivals (DSS) were, for Group I, 96%, for Group II 90%, and for Group III 95%. Patients in Group I had a significantly higher 5-year DSS than patients in Group II (p = 0.003) and not significantly different than patients in Group III (p = 0.367). Overall survival was not compromised by the inclusion of tylectomy in eye salvage therapy compared to eye salvage without tylectomy or primary enucleation. Disease-specific survival was better when tylectomy was included in eye salvage treatments. Tylectomy as part of multimodal treatment may contribute to the care of retinoblastoma patients with chemotherapy-resistant tumor, eyes with concomitant ocular complications, or at the risk of treatment abandonment.

Glaucoma secondary to congenital fibrovascular pupillary membrane: a single tertiary center experience

We report the clinical features, treatments, and outcomes of 9 infants with glaucoma secondary to congenital fibrovascular pupillary membrane. The clinical features included unilateral low vision, high intraocular pressure (IOP), enlarged and cloudy cornea, loss of anterior chamber, and pupillary membrane. All patients underwent membranectomy, peripheral iridectomy, pupilloplasty, and goniosynechialysis as primary treatment. The membranes were posterior to the iris in all 9 eyes. In 5 eyes, the membrane covered the ciliary processes, and in 1 eye the membrane reached the posterior lens capsule. Following primary surgery, 3 patients developed membrane recurrence, 4 had refractory elevated IOP, and 2 developed lens opacities. All 4 eyes with poor postoperative IOP control had iris root insertion anterior to the scleral spur. Five patients received additional surgeries including membranectomy, pupilloplasty, goniosynechialysis, cyclocryotherapy, ciliary photocoagulation, Amhed valve implantation, and lensectomy. One patient had refractory elevated IOP at last follow-up. IOP in the other 8 eyes was well controlled. None of the affected eyes was able to fix and follow at last follow-up.

Ocular Juvenile Xanthogranuloma With BRAF V600E Mutation in a Child

The authors present a case of bilateral painless progressive proptosis. A diagnosis of ocular juvenile xanthogranuloma was made based on clinical manifestations, histopathology, and immunohistochemistrical staining. Genetic testing discovered the BRAF V600E mutation. This patient did not respond to standard chemotherapy; however, he demonstrated regression after anti-BRAF targeted therapy. [J Pediatr Ophthalmol Strabismus. 2021;58(4):e19-e21.].

Primary laser therapy as monotherapy for discrete retinoblastoma

BACKGROUND/AIM

Laser photocoagulation is less invasive than chemotherapy (systemic, intra-arterial or periocular) and brachytherapy. We studied the safety and efficacy of laser as primary monotherapy for discrete retinoblastoma with well-defined borders and attached retina.

METHODS

A single-institution retrospective non-comparative review (2004-2018) of discrete retinoblastoma tumours managed with primary laser (532 or 810 nm wavelength, 0.5-1 s duration and power titrated until desired tumour whitening). Efficacy was evaluated by tumour long-term stability avoiding non-laser therapies. Safety was evaluated by frequency of laser-related complications and uncontrollable tumour progression.

RESULTS

Eligible were 112 tumours in 55 eyes of 44 patients. Laser monotherapy (median 2 sessions) achieved initial remission in 95/112 (85%) tumour. Initial encircling only laser photocoagulation was associated with tumour progression (9/11, one tumour had vitreous seeding) compared with direct or combined photocoagulation techniques (0/94 and 0/7 tumours, respectively, p<0.001). Direct laser had no vitreous seeding, haemorrhage or injury to vital structures. Tumour recurrences developed in 52/112 (46%) tumour but repeat laser achieved long-term stability, except five tumour recurrences that required invasive therapy. Receiver operating characteristic analysis identified threshold largest basal diameter of 3 disc diameters (DD) for successful laser monotherapy, where 92/106 (87%) of tumours ≤3 DD and 0/6>3 DD achieved long-term stability with laser monotherapy (p<0.001). Overall, 35/55 (64%) eyes and 24/44 (55%) patients achieved long-term stability with laser monotherapy. No eye was enucleated for uncontrollable tumour progression.

CONCLUSIONS

Discrete retinoblastoma ≤3 DD can be effectively and safely managed with laser monotherapy, sparing a significant proportion of patients/eyes from more invasive therapies.

Abstract B63: Survivorship, vision, and eye salvage following pars plana vitrectomy for residual active or recurrent retinoblastoma

Introduction: Intraocular surgery has long been taboo in the management of eyes with retinoblastoma due to concern of extraocular spread that carries poor survivorship. Pars plana vitrectomy (PPV) and tumor endoresection has recently emerged in China as an effective surgical treatment to salvage eyes with tumor resistant to chemotherapy, the current standard of care. To investigate the safety and efficacy of this novel treatment, we studied survivorship, visual acuity, and eye salvage rate of retinoblastoma children/eyes treated with PPV.

Methods: Outcomes were reviewed for 227 children (247 eyes) treated with PPV and endoresection for residual active tumor or recurrent tumor following chemotherapy at 29 Chinese centers between 2013 and 2014.

Results: At 5 years following PPV, 14 patients died, 8 related to the eye that had PPV. The 5-year overall survival rate following PPV was 93.7% (95% CI: 90.4% to 97.0%). The 5-year PPV eye-related survival rate (PPVSR) was 96.3% (95% CI: 93.8% to 98.9%). Children with PPV for residual active tumor had better survival than those with PPV for recurrent tumor (5-year PPVSR 98.1% vs. 91.4%, P = .021). Children with 1 to 3 cycles of neoadjuvant chemotherapy (intra-arterial or systemic chemotherapy) prior to PPV had similar survival to children with ≥4 cycles of chemotherapy (98.2% vs. 93.7%, P = .093). Children with adjuvant systemic chemotherapy following PPV had 100% (95% CI: 93.5% to 100%) 5-year PPVSR, not significantly higher than those without adjuvant chemotherapy (100% vs. 94.8%, P = .102). Of 94 eyes with partial or no retinectomy and documented visual acuity, the post-PPV visual acuity was 20/20-20/60 (23, 24%); 20/7-20/160 (6, 6%); 20/17-20/400 (9, 10%); counting fingers, hand motion, or light perception vision (42, 45%); and no light perception (NLP) (14, 15%). Complete retinectomy was performed on 93 of 247 (37.7%) eyes that, as expected, had NLP. The 5-year eye salvage rate following PPV was 80.7% (95% CI: 75.5% to 85.9%). PPV for residual active tumor and recurrent tumor had similar eye salvage rate (82.0% vs. 76.8%, P = .372). Eyes with International Intraocular Retinoblastoma Classification (IIRC) A, B, or C staging had better salvage rate than eyes with IIRC D or E staging (100.0% vs. 78.1%, P = .005). Eyes that received 1 to 3 cycles and ≥4 cycles of neoadjuvant chemotherapy had similar salvage rate (81.4% vs. 79.8%, P = .796).

Conclusion: We observed that PPV salvaged 80.7% of eyes with residual active tumor after primary chemotherapy or recurrent tumor after remission. The 5-year eye-specific survival was 96.3%, comparable to survivorship using other treatment modalities. More cycles of neoadjuvant chemotherapy did not improve survivorship or eye salvage rate. In this cohort, all children with adjuvant chemotherapy following PPV survived at 5 years. PPV may be a game changer to improve health outcomes of patients with retinoblastoma, with the potential to become the new standard of care.

Citation Format: Junyang Zhao, Zhao Xun Feng, Qiyan Li, Songyi Wu, Liwen Jin, Brenda L. Gallie. Survivorship, vision, and eye salvage following pars plana vitrectomy for residual active or recurrent retinoblastoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B63.

Impact of Systemic Chemotherapy and Delayed Enucleation on Survival of Children with Advanced Intraocular Retinoblastoma

PURPOSE

Primary enucleation is a well-established method to achieve cure for advanced intraocular retinoblastoma. Recent treatment advances have induced a trend toward trial eye salvage using chemotherapy or other modalities. We investigated how pre-enucleation/postenucleation systemic chemotherapy and the resulting delayed enucleation affect patient survival after failed trial eye salvage.

DESIGN

Multicenter, retrospective cohort study.

PARTICIPANTS

Children with Group D and E retinoblastoma primarily or secondarily enucleated at 29 Chinese treatment centers.

METHODS

Data reviewed included clinical staging, time from diagnosis to enucleation, numbers of cycles of carboplatin, etoposide/teniposide and vincristine chemotherapy, disease-specific survival (DSS), histopathology, and follow-up.

MAIN OUTCOME MEASURES

Primary outcome was DSS. Secondary outcome was histopathology of enucleated eyes.

RESULTS

Primarily enucleated eyes had significantly shorter delay from diagnosis to enucleation than eyes treated with pre-enucleation chemotherapy (P < 0.001). Delay between diagnosis and enucleation >3.5 months (Group D) and >2 months (Group E) decreased survival (Group D: P = 0.018; Group E: P = 0.017). Compared with primarily enucleated children, children with 1 to 3 cycles of pre-enucleation chemotherapy for Group E eyes had no significant difference in survival (P = 0.74), but those who received ≥4 cycles had worse survival (P = 0.025). After pre-enucleation chemotherapy, more children with Group E (but not Group D) eyes had high-risk histopathology (pT3/pT4) (Group D: P = 0.076; Group E: P < 0.001) and worse survival than those primarily enucleated (P < 0.001). Postenucleation chemotherapy improved survival of children with high-risk histopathology (pT3/pT4) (P = 0.001) but did not change survival of children with low-risk histopathology (pT1/pT2) (P = 0.52).

CONCLUSIONS

We observed that pre-enucleation chemotherapy offered no survival benefit and timely enucleation minimized risk of metastatic death. Postenucleation chemotherapy improved survival of children with high-risk histopathology but was not useful for those with low-risk histopathology. These findings facilitate informed discussion on the risks and benefits of delayed enucleation, the use of systemic chemotherapy for trial salvage of eyes with advanced intraocular retinoblastoma, and the specific children who benefit from postenucleation chemotherapy.

A replicating plasmid-based vector for GFP expression in Mycoplasma hyopneumoniae

Mycoplasma hyopneumoniae (M. hyopneumoniae) causes porcine enzootic pneumonia (PEP) that significantly affects the pig industry worldwide. Despite the availability of the whole genome sequence, studies on the pathogenesis of this organism have been limited due to the lack of a genetic manipulation system. Therefore, the aim of the current study was to generate a general GFP reporter vector based on a replicating plasmid. Here, we describe the feasibility of GFP reporter expression in M. hyopneumoniae (strain 168L) controlled by the p97 gene promoter of this mycoplasma. An expression plasmid (pMD18-TOgfp) containing the p97 gene promoter, and origin of replication (oriC) of M. hyopneumoniae, tetracycline resistant marker (tetM), and GFP was constructed and used to transform competent M. hyopneumoniae cells. We observed green fluorescence in M. hyopneumoniae transformants under fluorescence microscopy, which indicates that there was expression of the GFP reporter that was driven by the p97 gene promoter. Additionally, an electroporation method for M. hyopneumoniae with an efficiency of approximately 1 x 10(-6) transformants/μg plasmid DNA was optimized and is described herein. In conclusion, our data demonstrate the susceptibility of M. hyopneumoniae to genetic manipulation whereby foreign genes are expressed. This work may encourage the development of genetic tools to manipulate the genome of M. hyopneumoniae for functional genomic analyses.

Apoptosis induced by lipid-associated membrane proteins from Mycoplasma hyopneumoniae in a porcine lung epithelial cell line with the involvement of caspase 3 and the MAPK pathway

Lipid-associated membrane proteins (LAMPs) are important in the pathogenicity of the Mycoplasma genus of bacteria. We investigated whether Mycoplasma hyopneumoniae LAMPs have pathogenic potential by inducing apoptosis in a St. Jude porcine lung epithelial cell line (SJPL). LAMPs from a pathogenic strain of M. hyopneumoniae (strain 232) were used in the research. Our investigation made use of diamidino-phenylindole (DAPI) and acridine orange/ethidium bromide (AO/EB) staining, terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) analysis, and Annexin-V-propidium iodide staining. After LAMP treatment for 24 h, typical changes were induced, chromosomes were concentrated, apoptotic bodies were observed, the 3'-OH groups of cleaved genomes were exposed, and the percentage of apoptotic cells reached 36.5 ± 11.66%. Caspase 3 and caspase 8 were activated and cytochrome c (cyt c) was released from the mitochondria into the cytoplasm; poly ADP ribose polymerase (PARP) was digested into two fragments; p38 mitogen-activated protein kinase (MAPK) was phosphorylated; and the expression of pro-apoptosis protein Bax increased while the anti-apoptosis protein Bcl-2 decreased. LAMPs also stimulated SJPL cells to produce nitric oxide (NO) and superoxide. This study demonstrated that LAMPs from M. hyopneumoniae can induce apoptosis in SJPL cells through the activation of caspase 3, caspase 8, cyt c, Bax, and p38 MAPK, thereby contributing to our understanding of the pathogenesis of M. hyopneumoniae, which should improve the treatment of M. hyopneumoniae infections.

Comparative analysis of mucosal immunity to Mycoplasma hyopneumoniae in Jiangquhai porcine lean strain and DLY piglets

The Jiangquhai porcine lean strain (JQHPL) is a new pork meat-type strain that has been developed in recent years from the parent lines Duroc, Fengjing, and Jiangquhai pigs (DurocxFengjing pigxJiangquhai pig). Enzootic pneumonia (EP) in pigs induced by Mycoplasma hyopneumoniae (M. hyopneumoniae) is a chronic respiratory disease of pigs, generating high economic losses in the swine industry. Here, we investigated the degree of resistance to M. hyopneumoniae for the Jiangquhai porcine lean strain and the Duroc x Landrace x Yorkshire (DLY) pigs, which are Western commercial pigs that have been introduced in China. A total of 209 DLY piglets and 221 JQHPL piglets from 19 Landrace x Yorkshire and 22 JQHPL M. hyopneumoniae positive gestating sows with different expected dates of confinement were selected and raised in the same M. hyopneumoniae positive farrowing barn. When the oldest suckling piglets were 37 days old, nasal swabs were collected from all the piglets (ranging from 4 to 37 days old) to detect the M. hyopneumoniae pathogen using n-PCR and M. hyopneumoniae specific SIgA using ELISA. Positive M. hyopneumoniae infection rates in both the strains increased with age; however, positive rates for JQHPL were lower compared to DLY at 14 to 35 days old. The level of the specific SIgA rose rapidly in JQHPL respiratory tracts, particularly in piglets 21 to 35 days in age compared to DLY piglets of the same age; however, the level of the specific SIgA in DLY also marginally increased. In conclusion, JQHPL pigs exhibits higher resistance to M. hyopneumoniae compared to DLY. It is possible that this characteristic is caused by the faster and stronger mucosal immunity phenotype of the JQHPL strain.

[Clinical observation on treatment of 45 angina pectoris patients of coronary heart disease with taponin]

Forty-five patients suffering from angina pectoris of coronary heart disease (CHD) were successfully treated with Taponin. The effect of the treatment was compared with that of nifedipine. The clinical practice showed that the group treated with Taponin yielded better results. After medication, the patients were markedly relieved from angina pectoris of CHD. Meanwhile the improvement of electrocardiogram (EKG) and impedance cardiogram were also observed. The effective rate of EKG improvement was 83.7%. The treatment of angina pectoris of CHD with Taponin was significantly more effective in comparing with control group (P < 0.05).

[A study on the level of antibody against measles through maternal-fetal transfer and the immuno-response to measles vaccine among 4 to 7 month olds]

A total number of 143 infants at the age of 4 to 7 months from Yantai city-Shandong was selected for the study of antibody level against measles by maternal-fetal transfer and immuno-response to measles vaccine in October of 1993. The results showed that the negative rates of maternal-fetal antibody among infants of 4, 5, 6 and 7 month olds were 75.00%, 81.25%, 94.87% and 90.1%, respectively. The positive rates and geometric mean titers (GMTs) for immuno-response to measles vaccine were 92.86%, 84.38%, 97.44%, 100.00% and 55.17, 42.41, 69.95, 71.46, respectively. There were significant lower immune response to measles vaccine in infants who had high titer ( > 1:2) than those who had low titer ( <or= 1:2) of maternal-fetal antibody (chi 2 = 88.38, P < 0.001). In order to decrease the number of measles cases under 1 year old (especially under 9 month-old), the author suggested that the primary immunization for measles vaccine should be started at 6 month olds.

Chiral resolution of alpha,alpha'-bis[3-(N,N-diethylcarbamoyl)piperidino]-p-xylene, a novel antiplatelet compound

alpha,alpha'-Bis[3-(N,N-diethylcarbamoyl)piperidino]-p-xylene dihydrobromide, a novel antiplatelet agent, was resolved into three isomers A, B, and C, on a chiral alpha 1-acid glycoprotein analytical column using a mobile phase of 0.025 M phosphate buffer containing 0.025 M tetrabutylammonium hydrogen sulfate, at a pH of 6.5. The effect of molarity, temperature, pH, flow rate, and organic modifiers on the enantioselectivity was examined. Based on circular dichroic spectra at 220 nm, A and C appear to be the (-)- and (+)-enantiomers, respectively, and B the meso diastereomer. Attempts at resolution using Pirkle type columns gave unsatisfactory results. It appears that both hydrophobic and polar interactions between the compound and the stationary phase are important determinants of resolution.