Surgical management and post-operative functional outcomes of patients with a penile fracture-a single centre experience over 10 years

BACKGROUND

Penile fractures are uncommon urological emergencies which occur when there has been a breach in the tunica albuginea of the corpora cavernosum that may be unilateral and bilateral and can extend to involve the urethra.

AIM

To assess the management and outcomes of penile fractures in a single institution in Ireland.

METHODS

A retrospective review of the emergency theatre logbooks was performed between 2011 and 2021 to identify patients who had undergone an exploration for a suspected penile fracture.

OUTCOMES

Seventeen patients were initially identified on review of theatre logbooks as having an exploration for a suspected penile fracture. Two patients were excluded from the study due to a lack of clinical notes being available. A further 4 patients on chart review were found to not have a penile fracture at exploration.

RESULTS

Eleven patients had a confirmed penile fracture intra-operatively, four of whom had an associated urethral injury. Nine (9/11) patients had preserved normal erections post-operatively documented on follow-up; two, however, reported erectile dysfunction requiring phosphodiesterase inhibitors.

CLINICAL IMPLICATIONS

Our study supports urgent surgical exploration for penile fractures to ensure good functional outcomes.

STRENGTHS AND LIMITATIONS

This is a retrospective review of theatre logbooks to identify patients with a suspected penile fracture.

CONCLUSION

The results of our cohort show a good outcome of erectile function following surgical repair of a penile fracture (9/11; 82%). Four patients (4/11; 36%) had a urethral injury diagnosed intra-operatively, one of whom required a formal urethroplasty.

Peri-operative and long-term outcomes of kidney transplantation in patients with cystic fibrosis

INTRODUCTION

There is a lack of data regarding the peri-operative and long-term outcomes of kidney transplantation in cystic fibrosis (CF) patients. Herein, we report the peri-operative and long-term outcomes of kidney transplantation in CF patients.

MATERIALS AND METHODS

All CF patients who received a kidney transplant at the national kidney transplant center between 1993 and 2022 were identified. Recipients of the contralateral donor kidney were selected as a control group. Primary outcomes included 1-, 5-, and 10- year death-censored graft survival and overall survival. Secondary outcomes included peri-operative morbidity, acute graft rejection, delayed graft function (DGF), and length of stay (LOS).

RESULTS

Fourteen patients received a kidney transplant over the study period. Median age at transplantation was 35 (IQR 31, 40) years. The 1-, 5-, and 10-year death-censored graft survival was 92, 74, and 74% in the CF group compared to 100, 92, and 92% in the control group (p = .44). The 1-, 5-, and 10-year overall survival in the CF group was 85, 66, and 57% compared to 100, 92, and 82% in the control group (p = .036). There was no significant difference in peri-operative outcomes including LOS (10 vs. 11 days, p = .84), ICU admission (1 vs. 0 patients, p > .99), acute rejection episodes (2 vs. 1 patients, p > .99), and DGF (1 vs. 2 patients, p = .60).

CONCLUSION

CF patients have good long-term graft survival, however, overall survival was worse compared to a matched cohort. These data provide important information for transplant surgeons when considering suitable donor allografts in this unique patient population.

Kidney transplantation using ipsilateral arterial and contralateral venous anastomosis in a patient with failing vascular access

Herein, we describe our surgical technique and outcome of a kidney transplant in a patient with failing vascular access. A right donor kidney was transplanted into the right iliac fossa with an end-to-side arterial anastomosis to the ipsilateral right common iliac artery and end-to-side venous anastomosis to the contralateral left common iliac vein. The possibility of performing an ipsilateral arterial and contralateral venous anastomosis has been shown here to be successful. No post-operative surgical complications were encountered.

Predictive Value of Day of Treatment SPECT/CT Radiomics in Lobar Y90 Radioembolization of Hepatocellular Carcinoma: A Pilot Study

PURPOSE/OBJECTIVE(S)

Transarterial Radioembolization (TARE) with Yttrium-90 (Y90) microspheres is a well-tolerated liver-directed therapy for patients with inoperable hepatocellular carcinoma (HCC). Y90 TARE uses pretreatment and post-treatment single photon emission computed tomography (SPECT)/CT for assessment of microsphere biodistribution within tumor. Patients who develop disease progression (PD) after lobar TARE have poor overall survival (OS). Conventional radiography can require several months follow-up to assess tumor response per modified RECIST (mRECIST), resulting in treatment delays for patients with PD. Predictive models capable of identifying patients at high risk for PD could prompt close surveillance and rapid initiation of salvage therapies, enhancing disease control (DC). Predictive models in various cancers have incorporated radiomics, an analytic technique that extracts digital patterns from medical imaging. We hypothesized that radiomics of immediate post-treatment SPECT/CT can predict objective response (OR) to Y90 TARE.

MATERIALS/METHODS

A total of 38 lobar TARE treatments were assessed retrospectively. For all treatments, the prescribed dose was 120 Gy. SPECT/CT obtained immediately after TARE underwent radiomics analysis. A total of 75 features related to gray-level (GL) co-occurrence matrices (COM), dependency matrices (DM), run length matrices (RLM), zone size matrices (ZSM), and neighborhood difference matrices (NDM) were examined and balanced between cohorts with and without OR by aid of Gaussian noise up-sampling. Top features were chosen for a weighted k-nearest neighbors (KNN) classifier based on rank as determined by the RELIEF-F algorithm. Performance of the developed classifier was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

Most patients (76%) were Child-Pugh A cirrhotic, while Barcelona Clinic Liver Cancer (BCLC) stage was evenly distributed A to C. On radiographic review, 22 treatments (58%) achieved OR. The selected top features consisted of two from CT (GLNDM-based coarseness; GLDM-based small dependence low gray level emphasis) and two from SPECT (GLNDM-based coarseness; GLZSM-based zone entropy). The weighted KNN classifier built using the selected features demonstrated a relatively strong power for predicting OR, with a ROC area under curve (AUC) of 0.83.

CONCLUSION

In lobar TARE Y90 of inoperable HCC, a predictive model using texture features extracted from day of treatment SPECT/CT distinguished responders from non-responders with high accuracy. Limitations of this study include its retrospective nature and the absence of toxicity analysis. These findings suggest that predictive modeling incorporating SPECT/CT radiomics could enhance the therapeutic ratio for vulnerable HCC patients and merits further investigation in prospective clinical trials of Y90 TARE.

Technical and clinical assessment of latest technology SiPM integrated digital PETCT scanner

OBJECTIVE

The aim of this study was to conduct a technical and clinical evaluation of a Silicon Photomultiplier (SiPM) integrated digital Positron Emission Tomography - Computed Tomography (PETCT) Scanner using National Electrical Manufacturers Association (NEMA) NU 2- 2018 standards.

METHODS

System sensitivity was measured by using a NEMA sensitivity phantom. Scatter fraction, count-rate performance, accuracy of count loss, and timing resolution were all computed. Clinical images were acquired and image quality was assessed and compared with published studies.

RESULTS

At 1 cm, tangential, radial, and axial spatial resolutions were 3.02 mm, 3.02 mm, and 2.73 mm at full width half maximum (FWHM), respectively. Sensitivity at centre and 10 cm was 10.359 cps/kBq and 9.741 cps/kBq, respectively. The timing resolution was measured at 372 ps.

CONCLUSION

The digital PETCT exhibits a high-spatial resolution and a superior timing resolution, which advances the diagnostic ability to detect small lesions and boosts the diagnostic confidence.

IMPLICATIONS FOR PRACTICE

Increases clinical relevance by improving the ability to detect and differentiate tiny or low-contrast lesions without compromising radiopharmaceutical dose or overall scan time.

Clinical experience with non-invasive prenatal screening for single-gene disorders

OBJECTIVE

To assess the performance of a non-invasive prenatal screening test (NIPT) for a panel of dominant single-gene disorders (SGD) with a combined population incidence of 1 in 600.

METHODS

Cell-free fetal DNA isolated from maternal plasma samples accessioned from 14 April 2017 to 27 November 2019 was analyzed by next-generation sequencing, targeting 30 genes, to look for pathogenic or likely pathogenic variants implicated in 25 dominant conditions. The conditions included Noonan spectrum disorders, skeletal disorders, craniosynostosis syndromes, Cornelia de Lange syndrome, Alagille syndrome, tuberous sclerosis, epileptic encephalopathy, SYNGAP1-related intellectual disability, CHARGE syndrome, Sotos syndrome and Rett syndrome. NIPT-SGD was made available as a clinical service to women with a singleton pregnancy at ≥ 9 weeks' gestation, with testing on maternal and paternal genomic DNA to assist in interpretation. A minimum of 4.5% fetal fraction was required for test interpretation. Variants identified in the mother were deemed inconclusive with respect to fetal carrier status. Confirmatory prenatal or postnatal diagnostic testing was recommended for all screen-positive patients and follow-up information was requested. The screen-positive rates with respect to the clinical indication for testing were evaluated.

RESULTS

A NIPT-SGD result was available for 2208 women, of which 125 (5.7%) were positive. Elevated test-positive rates were observed for referrals with a family history of a disorder on the panel (20/132 (15.2%)) or a primary indication of fetal long-bone abnormality (60/178 (33.7%)), fetal craniofacial abnormality (6/21 (28.6%)), fetal lymphatic abnormality (20/150 (13.3%)) or major fetal cardiac defect (4/31 (12.9%)). For paternal age ≥ 40 years as a sole risk factor, the test-positive rate was 2/912 (0.2%). Of the 125 positive cases, follow-up information was available for 67 (53.6%), with none classified as false-positive. No false-negative cases were identified.

CONCLUSIONS

NIPT can assist in the early detection of a set of SGD, particularly when either abnormal ultrasound findings or a family history is present. Additional clinical studies are needed to evaluate the optimal design of the gene panel, define target populations and assess patient acceptability. NIPT-SGD offers a safe and early prenatal screening option. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Esophageal squamous cell cancer in Plummer-Vinson syndrome: Is lichen planus a missing link?

This retrospective study analyzed the occurrence of esophageal squamous cell cancer (ESCC) in a cohort of patients with Plummer-Vinson syndrome (PVS) and mucosal lichen planus (LP). ESCC occurred in 6.2% cases of PVS, more than half of whom had associated oral LP. Mucosal LP and PVS together may increase the predisposition to ESCC.

A 10-year Audit of Penile Prosthesis Insertion

Introduction Penile prosthesis (PP) insertion is the gold standard surgical treatment option for men with refractory Erectile Dysfunction (ED). PP insertion is considered effective but has a well-documented array of complications. Our aim was to assess outcomes following single-surgeon insertion of PP for ED within an Irish cohort. Methods Following review of the Hospital In-Patient Enquiry (HIPE) system, a retrospective chart review of all patients who underwent PP insertion over a 10-year period from 2008-2017 inclusive was performed, and an electronic database was analysed for results. Results One-hundred-and-eleven PPs were inserted in 96 patients. The most common aetiology for ED in our cohort was post-prostatectomy, affecting 25 (26%) patients. The most frequently implanted device was a 3-piece inflatable PP (3p-IPP) (AMS 700TM; American Medical Systems Inc., Minnesota, USA) and the peno-scrotal approach was utilised in the majority of patients (86, 77.5%). No intraoperative complications were recorded. Twelve (12.5%) patients developed peri-operative complications. Thirteen (13.5%) patients required device revision, the majority for device failure. Of the 71 patient satisfaction responses, 61 (85.9%) patients were satisfied with their PP. Conclusions This single-surgeon retrospective audit of PP surgery demonstrates complication rates in-line with internationally published data. Patients should be adequately counselled regarding possible complications, including device failure and erosion. PP insertion should be considered for suitable patients with refractory ED.

Management of a ureteric stricture post ureteroileal anastomosis of a renal transplant

A 58-year-old woman with a prior radical cystectomy and ileal conduit underwent a living-related donor renal transplant for end-stage renal disease secondary to autoimmune glomerulonephritis. She subsequently developed an ischaemic stricture of the transplant ureter. A successful ureteropyelostomy was performed with the native right ureter anastomosed to the pelvis of the renal transplant. She presented to the emergency department 18 months later feeling unwell and with raised inflammatory markers. Imaging demonstrated a large soft tissue mass over the right psoas muscle and hydronephrosis of the native right kidney. A nephrostomy and nephrostogram of the native right kidney diagnosed a urine leak from the native right kidney and she underwent an open right native nephrectomy. She recovered well postoperatively and continues to have excellent graft function. Renal transplantation in an abnormal urinary tract carries a high risk of complications. A multidisciplinary team approach is essential in offering the most appropriate treatment and ensuring good graft function is preserved.

The Irish experience of kidney transplantation among recipients with prior non-renal solid organ transplants: A retrospective study on short- and long-term outcomes

BACKGROUND

This study aims to evaluate allograft and patient outcomes among recipients of kidney transplants after non-renal solid organ transplants. We also aim to compare our findings with recipients of a repeat kidney transplant.

METHODS

We performed an analysis on kidney transplant recipients who underwent kidney transplantation after a non-renal solid organ transplant. Survival data were stratified into 2 groups: Group A (n = 37) consisted of recipients of a kidney transplant after prior non-renal solid organ transplant, and Group B (n = 330) consisted of recipients of a repeat kidney transplant.

RESULTS

The 1-,5-, and 10-year graft survival (death-censored) for recipients of a kidney transplant post-non-renal solid organ transplant (Group A) were 97.3%, 91.5%, and 86.9%, compared with 97.9%, 90.2%, and 83.4% for recipients of a repeat kidney transplant (Group B) (p = .32). The 1-, 5-, and 10-year patient survival rates were 97.3%, 82.7%, and 79.1% in Group A compared to 97.9%, 90.2%, and 83.4% in Group B. Unadjusted overall patient survival was significantly lower for Group A (p = .017).

CONCLUSION

Kidney transplant recipients who have undergone a previous non-renal solid organ transplant have similar allograft survival outcomes, but higher long-term mortality rates compared to repeat kidney transplant recipients.

Predictors of long-term renal allograft survival after second kidney transplantation

INTRODUCTION

Few studies investigate significant perioperative predictors for long-term renal allograft survival after second kidney transplant (SKT). We compared long-term survival following SKT with primary kidney transplant and determined predictors of renal allograft failure after SKT.

METHODS

Outcomes of all primary or second kidney transplant recipients at a national kidney transplant center between 1993 and 2017 were reviewed. The primary outcomes measurements were renal allograft survival for both first and second kidney transplants. Secondary outcome measurements were incidence of delayed graft function (DGF), incidence of acute rejection (AR), and predictors for renal allograft survival in SKT recipients.

RESULTS

In total, there were 392 SKTs and 2748 primary kidney transplants performed between 1993 and 2017. The 1-, 5-, and 10-year death-censored graft survival for deceased-donor recipients was 95.3%, 88.7%, and 78.2% for primary kidney transplant and 94.9%, 87.1%, and 74.9% for SKT (P = .0288). Survival of primary renal allograft <6 years (HR 0.6, P = .017), AR episodes (HR 1.6, P = .031), DGF (HR 2.0, P = .005), and HLA-DR MM (HR 1.7, P = .018) was independent predictors of long-term renal allograft failure after SKT.

CONCLUSION

These findings may provide important information on long-term survival outcomes after SKT and for identifying patients at risk for long-term renal allograft failure after SKT.

Pain relief after varicocele embolization: The patient's perspective

INTRODUCTION

Long-term efficacy of treatment with varicocele embolization is poorly documented from the patient's perspective. This study assessed patients' perceived changes in pain scores pre- and post-testicular vein embolization. In addition, the effect of testicular vein embolization on quality of life (QoL) parameters was assessed.

METHODS

All patients treated with embolization for varicocele-related orchalgia were analysed (2009-2015). A standardized pain impact questionnaire was used to assess pain scores pre- and post-procedure. The primary outcome was to assess patients' pain relief post-varicocele embolization. The secondary outcome was patients' perceived efficacy of the embolization procedure in terms of improvement in QoL parameters.

RESULTS

Sixty patients underwent varicocele embolization due to persistent orchalgia; of which 44 responded to the questionnaire. The mean pre-procedural pain score was 5.4/10 (range of 1.5-9). Post-procedure questionnaire was performed at a median of 58 months (range 28-106 months). At 1, 6 and 12 months post-procedure, the mean pain score was 1.57, 0.55 and 0.3, respectively. 50% (n = 22) reported complete pain relief 1-month post-embolization while 89% (n = 39) of patients reported complete resolution of pain at 1 year. Among the measured QoL parameters; varicocele embolization resulted in significant improvement in return to work, housework, socializing, exercise, sexual relations, and sleeping post-embolization (P < 0.01).

CONCLUSION

Varicocele embolization results in a durable reduction in pain scores compared to their pre-operative values. Information from this study will allow clinicians to convey the potential improvements in pain parameters to patients undergoing embolization of symptomatic varicoceles.

Long-Term Outcomes of Renal Transplant in Patients With End-Stage Renal Failure Due to Systemic Lupus Erythematosus and Granulomatosis With Polyangiitis

OBJECTIVES

Systemic lupus erythematosus and granulomatosis with polyangiitis are systemic inflammatory conditions associated with renalfailure that can recur after renal transplant. Patients with these conditions are treated with chronic immunosuppression, potentially increasing risk of secondary malignancies. Here, we investigated long-term outcomes in renal transplant recipients with these conditions.

MATERIALS AND METHODS

Transplant recipients with end-stage kidney disease due to systemic lupus erythematosus and granulomatosis with polyangiitis seen between 1982 and 2016 at a national kidney transplant center were included. Primary outcome variables were long-term allograft survival and incidence of secondary malignancy. Secondary outcome measures were incidence of delayed graft function, primary disease recurrence, and serum creatinine at follow-up.

RESULTS

Ninety-eight transplant procedures (90 from deceased donors) in 92 consecutive patients (mean age 42.3 ± 14.4 y) were included: 55 with systemic lupus erythematosus and 37 with granulomatosis with polyangiitis. Follow-up duration was 110.53 ± 81.95 months (range, 1-393 mo). Overall renal allograft survival was 94.7% at 1 year, 85.4% at 5 years, and 75.4% at 10 years posttransplant. Patientswith systemic lupus erythematosus showed overall allograft survival of 91.6% at 1 year, 84.3% at 5 years, and 74.4% at 10 years. There was 1 allograft failure due to recurrence of primary disease in this group. Patients with granulomatosis with polyangiitis showed overall allograft survival of 100% at 1 year, 92.4% at 5 years, and 92.4% at 10 years. There were 21 mortalities, with 5 (23.8%) due to secondary malignancy. In total, 46 malignancies were diagnosed in 31 patients.

CONCLUSIONS

We found excellent long-term renal allograft survival rates in patients with systemic lupus erythematosus and granulomatosis with polyangiitis, with secondary malignancy rates similar to those shown in recipients without autoimmune diseases. These findings provide clinicians with long-term data on transplant recipients with end-stage renal failure due to systemic inflammatory conditions.

Warm Ischemia Time at Vascular Anastomosis is an Independent Predictor for Delayed Graft Function in Kidney Transplant Recipients

OBJECTIVES

Delayed graft function after kidney transplant can affect patient and graft survival, resulting in prolonged hospital stay and need for dialysis. Ischemia times during organ procurement and reanastomosis at transplant are key factors in delayed graft function.

MATERIALS AND METHODS

We analyzed all living- and deceased-donor renal transplants in Ireland over a 33-month period, with effect of warm ischemia time during anastomosis on delayed graft function being the primary outcome. We performed statistical regression analyses to account for confounding variables. Patients had identical surgical technique and immunosuppression protocols.

RESULTS

Of 481 transplants during the study period, 20 patients were excluded because of paired-kidney exchange, nephron dosing transplant, or simul-taneous pancreas-kidney transplant. In the donor pool, 70% were donors after brainstem death, 3.6% were donors after cardiac death, and 26% were living donors. All living donors were direct altruistic donors and underwent stringent assessment via the ethics committee and multidisciplinary team meeting. Of living donors, 8% were not related. These were true altruistic donors who were acquaintances of the recipients and volunteered themselves for assessment. They were assessed in accordance with the declaration of Istanbul and received no compensation of any kind for donation. Of total patients, 18% had delayed graft function, defined as need for dialysis within 7 days of transplant. Warm ischemia time during anastomosis significantly affected risk of delayed graft function but not graft survival or function at 3 months. This factor did not correlate with hospital stay duration. Time on dialysis and recipient weight significantly correlated with risk of delayed graft function.

CONCLUSIONS

Our findings support a role for minimizing warm ischemia time during anastomosis to reduce delayed graft function and need for dialysis in the perioperative period. However, a longer time does not appear to affect creatinine levels and therefore graft function at 3 months.

Living donor renal transplant in a patient with end-stage renal disease due to Hermansky-Pudlak syndrome

Hermansky-Pudlak syndrome (HPS) is a rare genetic disorder characterised by oculocutaneous albinism, bleeding diathesis and end-stage renal disease (ESRD), due to interstitial deposition of ceroid lipofuscin. Renal transplantation is potentially a definitive treatment option for patients with ESRD due to HPS. Herein, we describe the case of a 55-year-old male patient with HPS that successfully underwent a living donor kidney transplant. We also emphasise the importance of multidisciplinary input during the preoperative, perioperative and postoperative phases in this high-risk clinical scenario.

Urothelial carcinoma of an allograft ureter 10 years after deceased donor kidney transplantation

The incidence of urothelial carcinoma (UC; formerly transitional cell carcinoma) is higher among renal transplant recipients compared with the general population. Upper urinary tract UC (UUT-UC) of allograft urothelium is a rare event with approximately 40 cases reported in the literature. Herein, we describe the clinical presentation and management of UUT-UC in a transplant ureter 10 years after deceased donor kidney transplantation.

Naphthalenesulphonic Acid Derivatives as Potential anti-HIV-1 Agents. Chemistry, Biology and Molecular Modelling of Their Inhibition of Reverse Transcriptase

Activity against human immunodeficiency virus (HIV) in the naphthalenesulphonic acid series is most pronounced in the disulphonic acid series. In this class of compounds, N-acyl derivatives of 4-amino-5-hydroxy-2,7-naphthalenedisulphonic acid demonstrate significant anti-HIV activity at non-toxic doses. The most potent compounds in this group of agents are bis naphthalenedisulphonic acids. A bis derivative containing a decamethylene spacer demonstrated activity against HIV-1, HIV-2 giant cell formation and reverse transcriptase (RT). This compound also demonstrated an in vitro therapeutic index (ratio of 50% cytotoxic concentration to 50% inhibitory antiviral concentration) of 10.6. Molecular modelling analyses of this agent, suramin, and several suramin analogues were undertaken to explain the potent anti-HIV-1 RT activity. These studies were carried out using the molecular decomposition/recomposition strategy, conformational searching, energy minimization and molecular dynamics (MD) simulation. The bis naphthalenedisulphonic acid derivative compound 1, having a flexible decamethylene spacer, was shown to be able to mimic the helical twist of the B-DNA backbone as a low energy conformer state.

Selective Inhibition of Myxovirus Replication by a Novel Series of Cholesterol-Naphthalenesulfonic Acid Hybrid Molecules

A novel series of hybrid molecules with cholesterol and naphthalenesulfonic acid have been synthesized and evaluated for their inhibitory activity against myxoviruses (respiratory syncytial virus [RSV], influenza A and B virus), Naphthalenesulfonic acids (compounds 1–3) and cholesterols (compounds 4 and 5) did not inhibit myxovirus-induced cytopathic-ity. However, hybrid molecules (compounds 6 and 7) proved active against RSV and influenza A virus but not influenza B virus. The antiviral effects of the hybrid compounds 6 and 7 were comparable to those of dextran sulfate. Mixtures of naphthalenesulfonic acid and cholesteryl chloroformate (compounds 1 and 5 molecules, corresponding to the hybrid molecule 6; and compounds 2 and 5, corresponding to the hybrid molecule 7) did not show antiviral activity. The mode of action of the cholesterol-linked naphthalenesulfonic acids can be attributed to inhibition of virus-cell fusion (influenza A virus) or inhibition of both virus-cell binding and fusion (RSV).

Inhibition of HIV-1-Induced Cytopathogenicity, Syncytium Formation, and Virus-Cell Binding by Naphthalenedisulphonic Acids through Interaction with the Viral Envelope gp120 Glycoprotein

Bis-naphthalenedisulphonic acid derivatives with a biphenyl spacer, 4,4′-[4,4′-biphenyldiylbis(sulphonyl-amino)]bis(5-hydroxy-2,7-naphthalenedisulphonic acid) and 3,3′-[4,4′-biphenyldiylbis(sulphonyl-amino)]bis(1,5-naphthalenedisulphonic acid), have previously been reported as potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) replication in cell culture. These compounds have also proved inhibitory to syncytium formation in cocultures of MOLT-4 cells with HIV-1-infected HUT-78 cells. They also inhibit the binding of HIV-1 virions to MT-4 cells as determined by a flow cytometric (FACS) method. Further studies on their mechanism of action by the FACS have revealed that the compounds inhibit the binding of anti-gp120 monoclonal antibody to the viral envelope glycoprotein gp120. Binding of OKT4A/Leu3a monoclonal antibody to the cellular CD4 receptor is not affected by the compounds. These results suggest that the anti-HIV-1 activity of the naphthalenedisulphonic acid derivatives can be attributed to inhibition of the gp120-CD4 interaction through binding of the compounds to the viral gp120 antigen.