Percutaneous functional spinal unit cementoplasty versus percutaneous kyphoplasty for severe osteoporotic vertebral compression fracture complicated with endplate-disc complex injury: A retrospective case-control study.

BACKGROUND: Severe osteoporotic vertebral compression fracture (SOVCF) is frequently complicated by endplatedisc complex (EDC) injury. While percutaneous kyphoplasty (PKP) can offer rapid analgesia and facilitate early activity, it does not restore vertebral height and may result in intervertebral leakage and untreated EDC injury. OBJECTIVE: This study aimed to evaluate the clinical outcomes of percutaneous functional spinal unit cementoplasty (PFSUP) for SOVCF complicated by EDC injury and compare its clinical and imaging outcomes with PKP. METHODS: This was a retrospective case-control study. Patients with SOVCF complicated with EDC injury between January 1, 2018, and December 31, 2019, were recruited and assigned to the PKP group and PFSUP group based on their treatment procedures Back pain was evaluated using the visual analog scale (VAS) and daily life activities were assessed using the Oswestry disability index (ODI). X-rays were employed to observe the presence and location of cement leakage, as well as to measure the sagittal vertical axis (SVA) and local kyphosis angle (LKA). Loss of correction was calculated by subtracting the LKA after surgery from that at the final follow-up visit Subsequent vertebral fracture (SVF) was confirmed using the Genant semi-quantitative method and/or MRI. RESULTS: A total of 64 patients were included in this study. Among them 41 cases were assigned to the PKP group (28 females, 74.8 years on average), while the remaining 23 cases were assigned to the PFSUP group (15 females, 76.3 years on average). All surgical interventions were successfully completed without major complications. Compared to the PKP group, the PFSUP group had longer operation time (70.28 ± 11.44 vs 44.5 ± 10.12, P< 0.001) higher frequencies of radiation exposure (97.6 ± 19.85 vs 38.6 ± 9.53, P< 0.001), and a lower cement leakage rate (26.1% vs. 41.5%, P< 0.001). One day after surgery and at the final follow-up the PFSUP group had lower VAS and ODI scores, as well as lower LKA and Sva values compared with the PKP group (all P< .001). At the final follow-up visit, the PFSUP group demonstrated a lower loss of correction (4.38 ± 2.71 vs. 10.19 ± 3.41 P< 0.001) and a lower SVF rate compared to the PKP group (21.7% vs. 31.7%, P< 0.001). CONCLUSION: PFSUP outperformed PKP in alleviating pain restoring and maintaining sagittal balance, and lowering the incidence of cement leakage and SVF for SOVCF with EDC injury However, PFSUP was associated with longer operation time and high radiation exposure frequencies.

Related factors of severe osteoporotic vertebral compression fracture and clinical outcomes of percutaneous kyphoplasty: A retrospective study.

BACKGROUND: Osteoporosis is the most common disease in postmenopausal women and the elderly, which can lead to vertebral compression fracture. OBJECTIVE: To investigate the related factors of severe osteoporotic vertebral compression fracture (SOVCF) and evaluate the long-term outcomes of percutaneous kyphoplasty (PKP) for treating SOVCF through comparison with mild OVCF (MOVCF). METHODS: From September 2015 to March 2019, 294 osteoporotic vertebral compression fracture (OVCF) patients treated with PKP were analyzed. Compression of the anterior margin of the fractured vertebral body beyond 2/3 of the original height was defined as SOVCF. Baseline data, clinical and imaging findings before and after surgery and at the last follow-up were recorded. Numerical Rating Scale (NRS) was used to evaluate low back pain, the Oswestry Disability Index (ODI) was used to evaluate activity of daily life. Anterior vertebral height (AVH) and local kyphosis angle (LKA) was used to evaluate radiographic outcomes. During the follow-up, patients with recurrent back pain were examined by MRI to identify new fractures and the incidence of adjacent vertebral fracture (AVF) was recorded. Age, sex, body mass index (BMI), dual energy X-ray absorptiometry based T value, duration of symptom, history of trauma, steroid use, and fracture site were collected for univariate logistic regression analysis Variables with a P-value of less than 0.05 were then included in multivariate analysis to determine the related factors for SOVCF. RESULTS: Logistic regression analysis indicated that longer duration of symptom (OR = 1.109, 95%CI: 1.038-1.185, P= 0.002), lower T value (OR = 0.332, 95%CI: 0.139-0.763, P= 0.001), and steroid use (OR = 31.294, 95%CI: 1.020-960.449, P= 0.049) were related factors of SOVCF. Compared with the MOVCF group, the SOVCF group had longer operation time (57.3 ± 13.51 minutes vs 44.9 ± 8.13 minutes, P< 0.001), more radiation exposure (39.9 ± 7.98 times vs 25.5 ± 4.01 times, P< 0.001), and higher cement leakage rate (55.81% vs 18.73%, P< 0.001). At the last follow-up, the SOVCF group had higher NRS (2.28 ± 0.85 vs 1.30 ± 0.71, P< 0.001), and ODI (16.23 ± 4.43 vs 12.88 ± 3.34, P< 0.001). After operation and at the last follow-up, the SOVCF group had higher LKA and lower AVH (all P< 0.05). The AVF rate at the last follow-up was higher in the SOVCF group at the last follow-up (4.78% vs 18.60%, P< 0.001). CONCLUSION: Lower T value, longer duration of disease, and steroid use were related factors of SOVCF. Compared with MOVCF, PKP for SOVCF had longer operation time, more radiation exposure, and higher cement leakage rate, and the long-term outcomes were worsen.

Percutaneous Functional Spinal Unit Cementoplasty versus Posterior Spinal Fixation with Vertebroplasty for Symptomatic Chronic Osteoporotic Vertebral Fractures: A Retrospective Study with a 2-Year Follow up.

PURPOSE: To compare the clinical efficacy of percutaneous functional spinal unit cementoplasty (PFSUP) and posterior spinal fixation combined with vertebroplasty (PSF + VP) for the treatment of symptomatic chronic osteoporotic vertebral fractures (SCOVFs). METHOD: Thirty-one patients with SCOVFs were included in this retrospective study and divided into PFSUP (n = 14) and PSF + VP (n = 17) groups. Visual analog scores (VAS) and Oswestry Disability Index (ODI) were recorded before and after surgery and at the last follow-up. Besides, the local kyphosis angle (LKA) and sagittal vertical axis (SVA) were measured. The operation duration, number of X-ray exposures, amount of blood loss, bed rest duration, hospitalization duration, and presence of complications were recorded. RESULT: The VAS, ODI, LKA, and SVA after surgery and at the last follow-up were significantly improved in both groups compared to preoperative measurements. The PFSUP group experienced shorter operation duration (78.2 ± 13.1 vs. 124.7 ± 14.7, p < 0.001), less blood loss (31.1 ± 8.1 vs. 334.7 ± 70.9, p < 0.001), more X-ray exposures (92.1 ± 14.3 vs. 29.4 ± 5.5, p < 0.001), shorter bed rest duration (12.4 ± 3.8 vs. 43.4 ± 10.0, p < 0.001), shorter hospitalization (6.6 ± 2.4 vs. 10.9 ± 2.7, p < 0.001), lower complication rate (28.5% vs. 64.7%, p < 0.05), and higher cement leakage rate (42.9% vs. 5.8%, p < 0.05) than the PSF + VP group. CONCLUSION: During the treatment of SCOVFs, the combination of PFSUP and PSF + VP can restore spinal stability, improve kyphosis, and relieve pain. PFSUP can reduce blood loss and complications, early mobilization, and shorten the hospital stay, but it is associated with a higher cement leakage rate and more radiation exposure.

Clinical outcomes with second injection after insufficient bone cement distribution in unilateral kyphoplasty for osteoporotic vertebral compressive fracture: a cohort retrospective study.

BACKGROUND: Bone cement distribution is an important factor affecting pain relief and long-term prognosis of osteoporotic vertebral compression fracture (OVCF) treated with vertebral augmentation. Unilateral percutaneous kyphoplasty (PKP) is the most common procedure, and insufficient bone cement distribution is more common than bilateral PKP. However, effective remedies are remain lack. In this study, sufficient cement distribution was achieved by adjusting the working channel followed by second cement injection as a remedy in cases with insufficient cement distribution, and the purpose was to evaluate the clinical outcomes by a retrospective cohort study. METHODS: From July 1, 2017 to July 31, 2020, OVCF patients treated with unilateral PKP were included in this retrospective cohort study. According to the bone cement distribution (insufficient cement distribution was confirmed when the cement did not exceed the mid line of the vertebral body in frontal film or/and the cement did not contact the upper/lower vertebral endplates in the lateral film.) and whether second injection was performed during surgery, the patients were divided into three groups. Insufficient group: patients with insufficient cement distribution confirmed by fluoroscopy or postoperative x-ray. Second injection group: patients with insufficient cement distribution was found during the procedure, and second injection was performed to improve the cement distribution. CONTROL GROUP: patients with sufficient cement distribution in one injection. The Primary outcome was cemented vertebrae re-collapse rate. The secondary outcomes included operative time, radiation exposure, cement leakage rate, VAS, ODI, and adjacent vertebral fracture rate. RESULTS: There are 34 cases in insufficient group, 45 cases in second injection group, and 241 cases in control group. There was no significant difference in baseline data and follow-up time among the three groups. PRIMARY OUTCOME: The injured vertebrae re-collapse rate of insufficient group was significantly higher than that of second injection group (42.22% vs 20.59%, P = 0.000) and control group (42.22% vs. 18.26%, P = 0.000). Kaplan-Meier survival analysis showed that there was no significant difference in the survival time between second injection group and control group (P = 0.741, Log-rank test), both of which were significant less than that in insufficient group (P = 0.032 and 0.000, respectively). SECONDARY OUTCOMES: There was no significant difference in VAS score and ODI after operation between second injection group and control group, both of which were superior to those in insufficient group (P = 0.000). At the final follow-up, there was no significant difference in VAS and ODI among the three groups (P > 0.05). The operation time of second injection group was significantly higher than that of insufficient group (53.41 ± 8.85 vs 44.18 ± 7.41, P = 0.000) and control group (53.41 ± 8.85 vs 44.28 ± 7.22, P = 0.000). The radiation exposure of the second injection group was significantly higher than that of insufficient group (40.09 ± 8.39 vs 30.38 ± 6.87, P = 0.000) and control group (40.09 ± 8.39 vs 31.31 ± 6.49, P = 0.000). The cement leakage rate of second injection group (20.59%) was comparable with that of insufficient group (24.44%) and control group (21.26%) (P = 0.877). The length of hospital stay of the second injection group (4.38 ± 1.72) was comparable with that of insufficient group (4.18 ± 1.60) and control group (4.52 ± 1.46) (P = 0.431). CONCLUSIONS: When cement distribution is insufficient during unilateral PKP, second injection may relieve early pain, reduce the incidence of cemented vertebral re-collapse and adjacent vertebral fracture, without increasing the cement leakage rate, although this procedure may increase the operation time and radiation exposure.

A Precise qNMR Method for the Rapid Quantification of Lot-to-Lot Variations in Multiple Quality Attributes of Pentosan Polysulfate Sodium.

Pentosan polysulfate sodium (PPS) is an orphan drug with anticoagulant activity. PPS is prepared from the chemical processing of xylan extracted from beechwood tree to yield a mixture of 4-6 kDa polysaccharides. The chain is mainly composed of sulfated xylose (Xyl) with branched 4-O-methyl-glucuronate (MGA). During generic drug development, the quality attributes (QAs) including monosaccharide composition, modification, and length need to be comparable to those found in the reference list drug (RLD). However, the range of QA variation of the RLD PPS has not been well characterized. Here, multiple PPS RLD lots were studied using quantitative NMR (qNMR) and diffusion ordered spectroscopy (DOSY) to quantitate the components in the mixture and to probe both inter- and intra-lot precision variability. The DOSY precision assessed using coefficient of variation (CV) was 6%, comparable to PPS inter-lot CV of 5%. The QAs obtained from 1D qNMR were highly precise with a precision CV < 1%. The inter-lot MGA content was 4.8 ± 0.1%, indicating a very consistent botanical raw material source. Other process-related chemical modification including aldehyde at 0.51 ± 0.04%, acetylation at 3.3 ± 0.2% and pyridine at 2.08 ± 0.06%, varied more than MGA content. The study demonstrated that 1D qNMR is a quick and precise method to reveal ranges of variation in multiple attributes of RLD PPS which can be used to assess equivalency with generic formulations. Interestingly, the synthetic process appeared to introduce more variations to the PPS product than the botanical source of the material.

HDAC6 inactivates Runx2 promoter to block osteogenesis of bone marrow stromal cells in age-related bone loss of mice.

BACKGROUND: Senile osteoporosis can cause bone fragility and increased risk for fractures and has been one of the most prevalent and severe diseases affecting the elderly population worldwidely. The underlying mechanisms are currently intensive areas of investigation. In age-related bone loss, decreased bone formation overweighs increased bone resorption. The molecular mechanisms underlying defective bone formation in age-related bone loss are not completely understood. In particular, the specific role of histone acetylation in age-related bone loss has not been examined thoroughly. METHODS: We employed 6- and 18-month-old mice to investigate the mechanisms of defective bone formation in age-related bone loss. Bone marrow stromal cells (BMSCs) were induced to undergo in vitro osteogenic differentiation. Chromatin immunoprecipitation (ChIP) was used to investigate the binding of histone deacetylases (HDACs) on Runx2 promoter in BMSCs. Luciferase reporter and transient transfection assay were employed to study Runx2 gene expression modulation by HDAC and androgen receptor (AR). siRNA and HDAC6 inhibitor, Tubastatin A, were used to inhibit HDAC6 in vitro. And systemic administration of Tubastatin A was used to block HDAC6 in vivo. RESULTS: Age-related trabecular bone loss was observed in 18-month-old mice compared with 6-month-old mice. In vitro osteogenic differentiation potential of BMSCs from 18-month-old mice was weaker than 6-month-old mice, in which there was Runx2 expression inactivation in BMSCs of 18-month-old mice compared with 6-month-old mice, which was attributable to HDAC6-mediated histone hypoacetylation in Runx2 promoter. There was competitive binding of HDAC6 and AR on Runx2 promoter to modulate Runx2 expression in BMSCs. More importantly, through siRNA- or specific inhibitor-mediated HDAC6 inhibition, we could activate Runx2 expression, rescue in vitro osteogenesis potential of BMSCs, and alleviate in vivo age-related bone loss of mice. CONCLUSION: HDAC6 accumulation and histone hypoacetylation on Runx2 promoter contributed to the attenuation of in vitro osteogenic differentiation potential of BMSCs from aged mice. Through HDAC6 inhibition, we could activate Runx2 expression and osteogenic differentiation potential of BMSCs from aged mice and alleviate the age-related bone loss of aged mice. Our study will benefit not only for understanding the age-related bone loss, but also for finding new therapies to treat senile osteoporosis.

Preliminary report of modified expansive laminoplasty in the treatment of thoracic ossification of the ligamentum flavum.

OBJECTIVE: This study was performed to evaluate the role of posterior suspension of the laminae-ossification of the ligamentum flavum complex combined with miniplate fixation (modified expansive thoracic laminoplasty) in treating thoracic ossification of the ligamentum flavum (TOLF). METHODS: Eight patients with TOLF treated by modified expansive thoracic laminoplasty were retrospectively analyzed. Their general information, operative time, intraoperative blood loss, and postoperative complications were recorded. Neurological functional recovery was evaluated by the modified Japanese Orthopaedic Association (mJOA) score and Hirabayashi recovery rate preoperatively, postoperatively, and at the final follow-up. Preoperative and postoperative imaging was performed, and the decompression range and internal fixation positioning were evaluated. RESULTS: The mJOA score significantly improved from 4.63 points preoperatively to 9.0 points at the final follow-up (Hirabayashi recovery rate of 77.75%). Postoperative computed tomography and magnetic resonance imaging revealed sufficient decompression of the surgical segment. At the final follow-up, the internal implants were well-placed, the lamina-ligamentum flavum complex showed no significant displacement, and neurological functional recovery was satisfactory. CONCLUSION: Surgical treatment of TOLF is complicated and high-risk. Characterized by simplicity and sufficient decompression, modified expansive thoracic laminoplasty can reduce the risk of cerebrospinal fluid leakage and nerve injury with satisfactory neurological functional recovery.

Pilose antler peptide potentiates osteoblast differentiation and inhibits osteoclastogenesis via manipulating the NF-κB pathway.

Bones are inflexible yet ever-changing metabolic organs, and bone homeostasis is maintained through two delicately regulated processes: bone construction and bone reabsorption. An imbalance in bone metabolism is linked to most orthopedic diseases, including osteoporosis and rheumatoid arthritis. Importantly, tumor necrosis factor-α (TNF-α) blocks osteoblast differentiation and stimulates osteoclast formation, resulting in delayed deposition of new bone and accelerated bone resorption, especially in rheumatoid arthritis patients with inflammatory conditions. Pilose antler peptide (PAP) isolated and purified from deer antlers has been shown to have beneficial effects on chronic inflammation. In the present study, we studied the impact of PAP on osteoblast differentiation and evaluated the regulatory mechanism, with particular emphasis on the effect of PAP on TNF-α-mediated NF-κB signaling. Mouse primary osteoblast cells were activated with bone morphogenetic protein-2 (BMP-2) for osteoblast differentiation. A significant stimulatory effect of PAP in osteoblastogenesis was observed using ALP activity and Alizarin Red S staining assays. Meanwhile, PAP significantly rescued TNF-α-induced impairment of osteoblast formation as well as mineralization. Furthermore, we found a similar trend upon analyzing osteoblast-specific gene expression. PAP significantly rescued TNF-α-mediated decrease in expression of osteoblast-specific genes. A molecular mechanism assay indicated that PAP significantly inhibited TNF-α-mediated stimulation of NF-κB signaling activity, as well as nuclear translocation of its subunit p65. Moreover, over-expression of p65 reversed the stimulatory effects of PAP on osteoblast differentiation. Furthermore, we also identified that PAP dose dependently inhibit osteoclastogenesis, and this effect might be achieved via suppressing NF-κB activity. In summary, this study shows that PAP promotes osteoblast differentiation and blocks TNF-α-mediated suppression of osteoblastogenesis in vitro via the NF-κB/p65 pathway, as well as inhibits osteoclastsogenesis in vitro. Therefore, PAP, a novel drug with both antiresorptive and osteoanabolic activity, shows therapeutic potential as an alternative treatment for osteolytic diseases, including rheumatoid arthritis and osteoporosis.

[MEDIUM-TERM EFFECTIVENESS OF Waveflex SYSTEM IN TREATMENT OF MULTIPLE LUMBAR DEGENERATIVE DISEASES].

OBJECTIVE: To evaluate the medium-term effectiveness of Waveflex system in the treatment of multiple lumbar degenerative diseases. METHODS: Between May 2010 and July 2012, 26 patients with multiple lumbar degenerative diseases underwent posterior decompression, transforaminal lumbar interbody fusion (TLIF), and internal fixation with Waveflex system. There were 15 males and 11 females, aged 23-65 years (mean, 34.2 years). The disease duration was 9 months to 8 years (median, 3 years and 3 months). The lesion located at L3-S1. The visual analogue scale (VAS), Oswestry disability index (ODI), and the short-form 36 health survey scale (SF-36) were used to evaluate the status of clinical recovery, meanwhile the Stauffer-Coventry evaluation standard was used to access the satisfaction at last follow-up; the disc space height (DSH), intervertebral angle (IVA), and range of motion (ROM) were measured on X-ray film or three-dimensional CT, and the adjacent segment degeneration was classified by Pfirrmann score based on MRI findings. RESULTS: All patients obtained primary incision healing without nerve injury, cerebrospinal fluid leakage, or internal fixation failure. All patients were followed up 31-50 months (mean, 40.6 months). The VAS, ODI, and SF-36 scores were significantly improved at 6 months after operation and last follow-up when compared with preoperative ones (P<0.05), but no significant difference was found between at 6 months and last follow-up (P>0.05). According to the Stauffer-Coventry evaluation standard, the results were excellent in 21 cases, good in 2 cases, moderate in 2 cases, and poor in 1 case, with an excellent and good rate of 88.5% at last follow-up. X-ray films showed that there was no complication of screws pulling-out or fixed rod rupture and displacement. At 7 days, 6 months, and last follow-up, the DSH of adjacent segment was significantly increased (P<0.05), and the ROM of adjacent segment was significantly decreased (P<0.05) when compared with preoperative ones; there was no significant difference in IVA between at pre- and post-operation (P>0.05). According to Brantigan grade for fusion, 19 cases were rated as grade E, 6 cases as grade D, and 1 case as grade C, and the fusion rate was 96%. There was no significant difference in Pfirrmann score between at pre-operation and last follow-up (Z=0.000, P=1.000). CONCLUSION: The Waveflex system combined with TLIF is effective and safe to treat multiple lumbar degenerative diseases during medium-term follow-up.

[A comparison of results between percutaneous transforaminal endoscopic discectomy and fenestration discectomy for lumbar disc herniation in the adolscents].

OBJECTIVE: To compare the preliminary clinical outcomes of percutaneous transforaminal endoscopic discectomy (PTED) and fenestration discectomy (FD) for lumbar disc herniation in the adolscents and further to summarize the clinical experience. METHODS: The data of 56 patients with single segment lumbar disc herniation who were adopted by our department from January 2011 to December 2013 were retrospectively studied. All patients were divided into 2 groups, including 30 patients undergoing PTED and 26 patients undergoing FD respectively. The factors including the length of skin incision, amount of intraoperative bleeding, operation time and duration of hospitalization were compared. Pfirrmann grading system was used for assessment of lumbar disc degeneration preoperatively and 1 year later. The visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopedic Association (JOA) scores were used to measure the clinical outcomes. RESULTS: There were significant differences in the observation factors such as the skin incision length, amount of intraoperative bleeding, operation time and duration of hospitalization between the PTED and FD groups (P < 0.05). After surgery, the patients in both groups were followed up for 12 months on average respectively. The postoperative lumbar disc degeneration in PTED group was decreased than that of in FD group. The postoperative VAS scores, ODI and JOA scores at each follow-up time point in both groups were significantly improved when compared with the preoperative ones (P < 0.05). There were no statistically significant differences between the 2 groups in the JOA score improvement rate (P > 0.05). According to 'the modified MacNab criteria, there were no statistically significant differences between the 2 groups in the excellent and good rate (P > 0.05). CONCLUSIONS: The preliminary clinical efficacy of both PTED and FD in the treatment of single segment lumbar disc herniation in the adolscents is satisfactory. However, PTED is a better minimally invasive surgical method with such advantages as less trauma, less blood loss, early function recovery, less effect on lumbar spinal stability and so on. The short-term outcomes of PTED are similar to that of FD.

[Comparison between bipedicular approach and uni-extrapedicular approach in application of vertebroplasty].

OBJECTIVE: To analyze the advantages and disadvantages of bipedicular approach and uni-extrapedicular approach of vertebroplasty in treating osteoporotic vertebral compression fractures (OVCFs). METHODS: From January 2008 to December 2010,53 patients with OVCFs were retrospectively analyzed. There were 24 males, 30 females with an average age of 66.9 years (ranged,59 to 88 years). Among them, 26 cases were treated with bipedicular approach, 28 cases were treated with uni-extrapedicular approach. The data of bone cement injection, radiology exposure times, operation time, bone cement leakage and vessels nerve complications were observed. Cobb angle, vertebral compression ration were observed by imaging data, and evaluate recovery of deformity. RESULTS: The data of bone cement injection, radiology exposure times, operation time, VAS score were (6.6 +/- 0.8) ml and (6.8 +/- 1.5) ml, (21.7 +/- 4.0) times and (17.9 +/- 3.6) times, (40.5 +/- 5.5) min and (31.6 +/- 9.1) min, (2.8 +/- 0.6) scores and (3.1 +/- 0.5) scores respectively. Cobb angle,vertebral compression ration were (7.6 +/- 2.0) degrees and (6.9 +/- 2.6) degrees, (18.1 +/- 5.8)% and (16.5 +/- 6.1)%. There were no vascular nerve complications occurred. For bone cement leakage, 3 cases (11%) in bipedicular approach and 3 cases (11%)in uni-extrapedicular approach. There was no significant differences between two groups in VAS score, recovery of vetebral body, Cobb angle, bone cement injection and bone cement leakage, but had significant differences in radiology exposure times and operation time (P<0.05). CONCLUSION: Both of two approaches can treat OVCFs well, especially extropedicle approach which could reduce operation time and radiation shoot frequency.

Chemical library screens targeting an HIV-1 accessory factor/host cell kinase complex identify novel antiretroviral compounds.

Nef is an HIV-1 accessory protein essential for AIDS progression and an attractive target for drug discovery. Lack of a catalytic function makes Nef difficult to assay in chemical library screens. We developed a high-throughput screening assay for inhibitors of Nef function by coupling it to one of its host cell binding partners, the Src-family kinase Hck. Hck activation is dependent upon Nef in this assay, providing a direct readout of Nef activity in vitro. Using this screen, a unique diphenylfuropyrimidine was identified as a strong inhibitor of Nef-dependent Hck activation. This compound also exhibited remarkable antiretroviral effects, blocking Nef-dependent HIV replication in cell culture. Structurally related analogs were synthesized and shown to exhibit similar Nef-dependent antiviral activity, identifying the diphenylfuropyrimidine substructure as a new lead for antiretroviral drug development. This study demonstrates that coupling noncatalytic HIV accessory factors with host cell target proteins addressable by high-throughput assays may afford new avenues for the discovery of anti-HIV agents.