Type III NRG-1 plays a regulatory role in the regeneration process of nerves from the beginning of transplantation.

The present study investigated the effect of type III Neuregulin-1 (NRG-1) on changes in the myelin sheath and the recovery of nerve function during the regeneration process following autologous nerve transplantation. Seventy-two Sprague-Dawley rats were divided into a Blank, Model and (antisense oligonucleotide, ASON) group. The Model and ASON groups of SD rats were subjected to autologous nerve transplantation, and the Blank group only had the sciatic nerve exposed. The Model and ASON groups were given local injections of 2 ml PBS buffer solution and 2 ml ASON of Type III NRG-1, respectively, the NRG-1 type III was inhibited by ASON. Changes in the sciatic nerve functional index (SFI) and conduction velocities were observed at different 6 time points. Regeneration of the myelin sheath was observed using transmission electron microscopy. Type III NRG-1 protein was detected using Western blotting and immunohistochemistry, and NRG-1 mRNA was detected using PCR. The SFI of the ASON group was lower than the Model group after transplantation. The conduction velocities of the ASON group on the 14th and 21st days after autologous nerve transplantation were lower than the Model group (P < 0.01). The protein and mRNA expression of type III NRG-1 in the ASON group was lower than the Model group at all 6 time points. The area of medullated nerve fibres was significantly different between the ASON group and the Model group on the 3rd day (P < 0.05), as was the number of medullated nerve fibres per unit area (P < 0.01). The diameter of axons was obviously different between the two groups (P < 0.01). Type III NRG-1 played an important regulatory role in the regeneration process of the nerve from the beginning of transplantation to the 28th day.

Advanced glycation end products impair coronary artery BK channels via AMPK/Akt/FBXO32 signaling pathway.

Background: Advanced glycation end products (AGEs) impair vascular physiology in Diabetes mellitus (DM). However, the underlying mechanisms remain unclear. Vascular large conductance calcium-activated potassium (BK) channels play important roles in coronary arterial function.Purpose: Our study aimed to investigate the regulatory role of AGEs in BK channels.Research Design: Using gavage of vehicle (V, normal saline) or aminoguanidine (A) for 8 weeks, normal and diabetic rats were divided into four groups: C+V group, DM+V group, C+A group, and DM+A group.Study Sample: Coronary arteries from different groups of rats and human coronary smooth muscle cells were used in this study.Data Collection and Analysis: Data were presented as mean ± SEM (standard error of mean). Student's t-test was used to compare data between two groups. One-way ANOVA with post-hoc LSD analysis was used to compare data between multiple groups.Results: Compared to the C+V group, vascular contraction induced by iberiotoxin (IBTX), a BK channel inhibitor, was impaired, and BK channel densities decreased in the DM+V group. However, aminoguanidine administration reduced the impairment. Protein expression of BK-ß1, phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK), and protein kinase B (PKB or Akt) were down-regulated, while F-box protein 32 (FBXO32) expression increased in the DM+V group and in high glucose (HG) cultured human coronary smooth muscle cells. Treatment with aminoguanidine in vitro and in vivo could reverse the above protein expression. The effect of aminoguanidine on the improvement of BK channel function by inhibiting the generation of AGEs was reversed by adding MK2206 (Akt inhibitor) or Compound C (AMPK inhibitor) in HG conditions in vitro.Conclusions: AGEs aggravate BK channel dysfunction via the AMPK/Akt/FBXO32 signaling pathway.

Treatment of periprosthetic knee infection and coexistent periprosthetic fracture: A case report and literature review.

BACKGROUND: Periprosthetic joint infection (PJI) and periprosthetic fracture (PPF) are among the most serious complications following total knee arthroplasty. Herein, we present one patient with these two complications with details on the characteristics, treatment strategy, and outcome. CASE SUMMARY: A 69-year-old female patient who suffered from PJI and PPF following total knee arthroplasty was treated by a two-stage revision surgery. After thorough foreign material removal and debridement, we used a plate that was covered with antibiotic-loaded bone cement to link with a hand-made cement spacer to occupy the joint space and fix the fracture. Although the infection was cured, the fracture did not heal and caused bone defect due to the long interval between debridement and revision. In the revision surgery, a cemented stem and cortical allogenic splints were used to reconstruct the fracture and bone defect. At the final follow-up 27 mo after revision, the patient was satisfied with postoperative knee functions with satisfactory range of motion (104º) and Hospital for Special Surgery knee score (82 points). The radiographs showed no loosening of the prosthesis and that the bone grafts healed well with the femur. CONCLUSION: Our two-stage revision surgery has proved to be successful and may be considered in other patients with PJI and PPF.

Changes in Type II NRG-1 Expression during Regeneration Following Autologous Nerve Transplantation in Rats.

AIM: To investigate the changes in type II neuregulin-1 (NRG-1) during the regeneration process following autologous sciatic nerve transplantation in rats. MATERIAL AND METHODS: In total, 40 healthy male Sprague-Dawley (SD) rats of clean grade with body weights between 250 g and 300 g were randomly divided into an experimental and control group, with 20 rats per group. Five time points were set, including the 3 < sup > rd < /sup > , 7 < sup > th < /sup > , 14 < sup > th < /sup > , 21 < sup > st < /sup > and 28 < sup > th < /sup > days after surgery. In the experimental group, reversed autologous transplantation of the sciatic nerve was performed, while in the control group, the sciatic nerve was simply exposed without autologous transplantation. At the different time points, changes in the rat footprints were observed, the sciatic functional index (SFI) was calculated, changes in the regeneration of the myelin sheath at the nerve end after transplantation were observed by transmission electron microscopy, changes in type II NRG-1 protein expression were detected by a western blot analysis, and changes in type II NRG-1 mRNA expression were detected by real-time PCR. RESULTS: The SFI in the experimental group was lower than that in the control group at all time points after surgery, and the SFI in the experimental group gradually increased; these differences were statistically significant (p < 0.05). The expression of type II NRG-1 protein in the experimental group was significantly increased on the 3rd day after nerve transplantation and peaked on the 7 < sup > th < /sup > day, which continued until the 28 < sup > th < /sup > day after surgery, indicating a significant difference from the control group (p < 0.01). NRG-1 mRNA expression was markedly increased on the 7th day after nerve transplantation, further increased, and peaked on the 14 < sup > th < /sup > day (p < 0.01). The area of medullated nerve fibers (?m2) in the experimental group significantly differed from that in the control group on the 7 < sup > th < /sup > , 14 < sup > th < /sup > , 21 < sup > st < /sup > and 28 < sup > th < /sup > days (p < 0.01), and the diameters of the axons in the experimental group notably differed from those in the control group on the 7 < sup > th < /sup > , 14 < sup > th < /sup > and 21 < sup > st < /sup > days (p < 0.01). CONCLUSION: Type II NRG-1 expression peaked between the 3 < sup > rd < /sup > day and 14 < sup > th < /sup > day after autologous nerve transplantation and is likely involved in the regulation of myelin sheath regeneration during this period.

Anti-high-mobility group box-1 (HMGB1) mediates the apoptosis of alveolar epithelial cells (AEC) by receptor of advanced glycation end-products (RAGE)/c-Jun N-terminal kinase (JNK) pathway in the rats of crush injuries.

OBJECTIVES: The lung injury is often secondary to severe trauma. In the model of crush syndrome, there may be secondary lung injury. We hypothesize that high-mobility group box 1 (HMGB1), released from muscle tissue, mediates the apoptosis of alveolar epithelial cells (AEC) via HMGB1/Receptor of advanced glycation end-products (RAGE)/c-Jun N-terminal kinase (JNK) pathway. The study aimed to investigate how HMGB1 mediated the apoptosis of AEC in the rat model. METHODS: Seventy-five SD male rats were randomly divided into five groups: CS, CS + vehicle, CS + Ethyl pyruvate (EP), CS + FPS-ZM1 group, and CS + SP600125 groups. When the rats CS model were completed after 24 h, the rats were sacrificed. We collected the serum and the whole lung tissues. Inflammatory cytokines were measured in serum samples. Western blot and RT-qPCR were used to quantify the protein and mRNA. Lastly, apoptotic cells were detected by TUNEL. We used SPSS 25.0 for statistical analyses. RESULTS: Nine rats died during the experiments. Dead rats were excluded from further analysis. Compared to the CS group, levels of HMGB1 and inflammatory cytokines in serum were downregulated in CS + EP, CS + FPS-ZM1, and CS + SP600125 groups. Western blot and RT-qPCR analysis revealed a significant downregulation of HMGB1, RAGE, and phosphorylated-JNK in CS + EP, CS + FPS-ZM1, and CS + SP600125 groups, compared with the CS groups, excluding total-JNK mRNA. Apoptosis of AEC was used TUNEL to assess. We found the TUNEL-positive cells were downregulated in CS + EP, CS + FPS-ZM1, and CS + SP600125 groups. CONCLUSION: The remote lung injury begins early after crush injuries. The HMGB1/RAGE/JNK signaling axis is an attractive target to abrogate the apoptosis of AEC after crush injuries.

Target-Based Virtual Screening and LC/MS-Guided Isolation Procedure for Identifying Phloroglucinol-Terpenoid Inhibitors of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to more than 5 million deaths worldwide to date. Due to the limited therapeutic options so far available, target-based virtual screening with LC/MS support was applied to identify the novel and high-content compounds 1-4 with inhibitory effects on SARS-CoV-2 in Vero E6 cells from the plant Dryopteris wallichiana. These compounds were also evaluated against SARS-CoV-2 in Calu-3 cells and showed unambiguous inhibitory activity. The inhibition assay of targets showed that compounds 3 and 4 mainly inhibited SARS-CoV-2 3CLpro, with effective Kd values. Through docking and molecular dynamics modeling, the binding site is described, providing a comprehensive understanding of 3CLpro and interactions for 3, including hydrogen bonds, hydrophobic bonds, and the spatial occupation of the B ring. Compounds 3 and 4 represent new, potential lead compounds for the development of anti-SARS-CoV-2 drugs. This study has led to the development of a target-based virtual screening method for exploring the potency of natural products and for identifying natural bioactive compounds for possible COVID-19 treatment.

Vitamin E-Enhanced Liners in Primary Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

OBJECTIVE: Adding vitamin E to highly cross-linked polyethylene liners is frequently performed in clinical practice, aiming at reducing liner wear, increasing liner survival, and delaying revision surgery. This study is aimed at evaluating the revision rate, total femoral head penetration, and postoperative clinical function of highly cross-linked polyethylene liners with and without vitamin E in total hip arthroplasty. METHODS: We conducted a systematic literature search to identify the use of highly cross-linked vitamin E liners compared to other liners in patients who received total hip arthroplasty (THA) before April 2021. The study quality assessment and data collection were conducted by two independent reviewers. Studies were artificially grouped, and vitamin E-enhanced liners (VE-PE) were compared with vitamin E-free liners (non-VE-PE). Analyses were executed using Review Manager version 5.4.1. RESULTS: From the preliminary screening of 568 studies, fourteen studies met the research criteria. Compared to non-VE-PE, using VE-PE reduced the all-cause revision rate (odds ratio = 0.54; 95% confidence interval (CI) 0.40, 0.73; P < 0.0001). The total femoral head penetration of the VE-PE was lower than that of the non-VE-PE (mean difference = -0.10; 95% CI -0.17, -0.03; P = 0.007). However, there was no difference in clinical function, including the Harris Hip Score and EuroQol Five-Dimension Questionnaire scores. CONCLUSION: Compared to the liners without vitamin E, the addition of vitamin E to liners could reduce the all-cause revision rate by approximately 46% in the short-term follow-up. In addition, even though addition of vitamin E could also slow down femoral head penetration, there is no contribution to clinical function.

The morphological mapping of lateral compression type 1 pelvic fracture and pelvic ring stability classification: a finite element analysis.

PURPOSE: This finite element analysis assessed lateral compression (LC-1) fracture stability using machine learning for morphological mapping and classification of pelvic ring stability. METHODS: Computed tomography (CT) files of LC-1 pelvic fractures were collected. After morphological mapping and producing matrix data, we used K-means clustering in unsupervised machine learning to classify the fractures. Based on these subtypes, we manually added fracture lines in ANSYS software. Finally, we performed a finite element analysis of a normal pelvis and eight fracture subtypes based on von Mises stress and total deformation changes. RESULTS: A total of 218 consecutive cases were analyzed. According to the three main factors-zone of sacral injury and completion, pubic ramus injury side, and the sagittal rotation of the injured hemipelvis-the LC-1 injuries were classified into eight subtypes (I-VIII). No significant differences in stress or deformation were observed between unilateral and bilateral public ramus fractures. Subtypes VI and VIII showed the maximum stress while subtypes V-VIII showed the maximum deformation in the total pelvis and sacrum. The subtypes did not differ in superior public ramus deformation. CONCLUSIONS: Complete fracture of sacrum zones 2/3 may be a feature of unstable LC-1 fractures. Surgeons should give surgical strategies for subtypes V-VIII.

A novel decision tree model based on chromosome imbalances in cell-free DNA and CA-125 in the differential diagnosis of ovarian cancer.

OBJECTIVE: CA-125 is widely used as biomarker of ovarian cancer. However, CA-125 suffers low accuracy. We developed a hybrid analytical model, the Ovarian Cancer Decision Tree (OCDT), employing a two-layer decision tree, which considers genetic alteration information from cell-free DNA along with CA-125 value to distinguish malignant tumors from benign tumors. METHODS: We consider major copy number alterations at whole chromosome and chromosome-arm level as the main feature of our detection model. Fifty-eight patients diagnosed with malignant tumors, 66 with borderline tumors, and 10 with benign tumors were enrolled. RESULTS: Genetic analysis revealed significant arm-level imbalances in most malignant tumors, especially in high-grade serous cancers in which 12 chromosome arms with significant aneuploidy (P<0.01) were identified, including 7 arms with significant gains and 5 with significant losses. The area under receiver operating characteristic curve (AUC) was 0.8985 for copy number variations analysis, compared to 0.8751 of CA125. The OCDT was generated with a cancerous score (CScore) threshold of 5.18 for the first level, and a CA-125 value of 103.1 for the second level. Our most optimized OCDT model achieved an AUC of 0.975. CONCLUSIONS: The results suggested that genetic variations extracted from cfDNA can be combined with CA-125, and together improved the differential diagnosis of malignant from benign ovarian tumors. The model would aid in the pre-operative assessment of women with adnexal masses. Future clinical trials need to be conducted to further evaluate the value of CScore in clinical settings and search for the optimal threshold for malignancy detection.

Cardiovascular disease-specific mortality in 270,618 patients with non-small cell lung cancer.

BACKGROUND: This study aimed to investigate the trend of cardiovascular disease (CVD)-specific mortality in patients with non-small cell lung cancer (NSCLC) and identify prognostic factors for CVD-specific death in stage NSCLC patients. METHODS: In this study, 270,618 NSCLC patients were collected from the Surveillance, Epidemiology, and End Results database. CVD- and NSCLC-specific cumulative mortality and proportion of death were calculated and graphically displayed to describe the probability of specific endpoints. Prognostic factors for CVD-specific mortality were evaluated by cause-specific hazard ratios (HR) with 95% confidence intervals (CI) using the competing risk model with non-cardiovascular death as competing risks. RESULTS: Among all competing causes of death, lung cancer resulted in the highest cumulative mortality, followed by CVDs and other causes. In the proportion of cause-specific death, heart diseases accounted for approximately 5.3% of the total death, only secondary to primary cancer. In all three stages, higher age, squamous cell carcinoma, and no-or-unknown chemotherapy and/or radiotherapy were associated with a higher risk of CVD-specific death, while surgery treatment seemed to be a protective factor. Female gender was statistically related to CVD-specific death in stage I and III patients with HRs of 0.84 (0.78-0.91) and 0.84 (0.77-0.93), respectively. Interestingly, right-sided laterality was correlated with lower CVD-specific mortality with HR of 0.82 (0.74-0.90) in stage III. CONCLUSIONS: This study illustrated the historical trend of CVD-specific death in NSCLC patients and assesses potential prognostic risk factors, highlighting the involvement of cardio-oncology teams in cancer treatment to provide optimal comprehensive care and long-term surveillance for cancer patients.

Bilaterally Primary Cementless Total Hip Arthroplasty for Severe Hip Ankylosis with Ankylosing Spondylitis.

OBJECTIVES: Total hip arthroplasty is a reliable therapeutic intervention in patients with ankylosing spondylitis, in whom the aims of surgery are to reduce pain, restore hip function and improve quality of life. The current study is a retrospective analysis of the clinical and radiographic findings in a consecutive series of patients with hip ankylosis associated with severe ankylosing spondylitis who underwent bilateral primary total hip arthroplasty using non-cemented components. METHODS: From June 2008 to May 2012, total hip arthroplasty was performed on 34 hips in 17 patients with bilateral ankylosis caused by ankylosing spondylitis. The study patients included 13 men and 4 women with a mean age of 24.2 years. The mean duration of disease was 8.3 years and the average duration of hip involvement was 7.6 years. All patients had severe hip pain and dysfunction with bilateral bony ankylosis and no range of motion preoperatively and all underwent bilateral cementless total hip arthroplasty performed by a single surgeon. Joint pain, range of motion (ROM), and Harris hip scores were assessed to evaluate the postoperative results. RESULTS: At a mean follow-up of 31.7 months, all patients had experienced significant clinical improvement in function, ROM, posture and ambulation. At the final follow-up, the mean postoperative flexion ROM was 134.4° compared with 0° preoperatively. Similar improvements were seen in hip abduction, adduction, internal rotation and external rotation. Postoperatively, 23 hips were completely pain-free, six had only occasional discomfort, three mild to moderate pain and two severe pain. The average Harris Hip Score improved from 23.7 preoperatively to 65.8 postoperatively. No stems had loosened at the final follow-up in any patient, nor had any revision surgery been required. CONCLUSIONS: Bilateral severe hip ankylosis in patients with ankylosing spondylitis can be treated with cementless bilateral synchronous total hip arthroplasty, which can greatly improve hip joint function and relieve pain without significant complications. Provided the overall physical condition of a patient and their economic situation make surgery a feasible option and the surgeon is experienced, this treatment is a worthwhile surgical intervention for bilateral hip bony ankylosis. However, the technically demanding nature of the procedure and potential pre- and post-operative problems should not be underestimated.

Functions and mechanisms of intermittent negative pressure for osteogenesis in human bone marrow mesenchymal stem cells.

The present study aimed to determine the mechanism by which low­intensity intermittent negative pressure affects the differentiation and proliferation of human mesenchymal stem cells (MSCs). Alkaline phosphatase (ALP) activity, type I collagen and vascular endothelial growth factor (VEGF) were detected to analyze differentiation. MTT and flow cytometry were employed to measure proliferation and apoptosis. Western blot analysis was used to examine endoplasmic reticulum (ER) stress­associated factors. This study was divided into two groups, including a normal group (without any treatment) and vacuum group (treated with a vacuum). There was a significant decrease in the proliferation of cells in the vacuum group. The number of cells in S phase was reduced significantly, while the rate of apoptosis and the activity of ALP were markedly increased under vacuum conditions. Expression of collagen type I and VEGF was significantly increased, and the ratio of osteoprotegrin to osteoprotegrin ligand was decreased significantly in the vacuum group. ER stress­associated proteins, p­PRKR­like ER kinase, inositol­requiring enzyme 1 and cleaved activating transcription factor 6, as well as the downstream factors, were activated when treated with negative pressure. In conclusion, treatment with low­intensity and intermittent negative pressure may inhibit the proliferation of MSCs and trigger ER stress­associated cellular apoptosis, further enhancing osteogenesis activity and inducing differentiation to osteoblasts.

[Application of allogeneic bone in surgical treatment of benign bone neoplasm].

OBJECTIVE: To evaluate the clinical outcomes of allogeneic bone grafting for bone defect resulting from benign neoplasm resection and discuss the clinical application and bone defect repair mechanisms of allogeneic bone. METHODS: A retrospective review was conducted of 135 patients with benign neoplasm resection who received bone defect filling with the allogeneic bone graft. RESULTS: In the 104 patients with complete clinical follow-up data, 96 achieved bone union, 7 experienced relapses to require surgical intervention and 1 had severe infection to lead to failure of the operation. The mean time for bone union was 9.7 months, and during the follow-up, no viral disease in relation to the graft was found after surgery. CONCLUSION: Bone defect filling with allogeneic bone graft can be simple and safe in comparison with that with autograft or other biomaterials, and the bone healing time, infection rate and local tumor recurrence can be comparable with the autograft.

Construction of a novel chimera consisting of a chelator-containing Tat peptide conjugated to a morpholino antisense oligomer for technetium-99m labeling and accelerating cellular kinetics.

The attempt to target the limited copies of messenger RNA (mRNA) in vivo with radiolabeled nucleobase oligomers as antisense probes is challenging. Selecting an antisense molecule with superior properties, enhancing the cellular kinetics, and improving the radiolabeling chemistry would be the reasonable approach to accomplish this goal. The present study reports a method to construct a chimera of phosphorodiamidate morpholino nucleobase oligomer (MORF) covalently conjugated to a peptide containing a cell membrane transduction Tat peptide and an N(2)S(2) chelator for technetium-99m ((99m)Tc) radiolabeling (N(2)S(2)-Tat-MORF). The radiolabeling properties and cellular kinetics of (99m)Tc-N(2)S(2)-Tat-MORF were measured. As hypothesized, the preparation of (99m)Tc-N(2)S(2)-Tat-MORF could be achieved by an instant one-step method with labeling efficiency greater than 95%, and the (99m)Tc-N(2)S(2)-Tat-MORF showed distinct properties in cell culture from those of a control, the same MORF sequence without Tat but with mercaptoacetyltriglycine (MAG(3)) as chelator for (99m)Tc ((99m)Tc-MAG(3)-MORF). (99m)Tc-N(2)S(2)-Tat-MORF achieved maximum accumulation of about 35% within 2 h, while (99m)Tc-MAG(3)-MORF showed lower and steadily increasing accumulations but of less than 1% in 24 h. These preliminary results demonstrated that the proposed chimera has properties for easy labeling, and (99m)Tc-N(2)S(2)-Tat-MORF prepared by this method possesses enhanced cellular kinetics and merits further investigation for in vivo mRNA targeting.

Electrostatic binding with tat and other cationic peptides increases cell accumulation of 99mTc-antisense DNAs without entrapment.

UNLABELLED: An important limitation restricting antisense nuclear medicine imaging is low radioactivity accumulations in target cells. The Tat peptide (Tat), a basic domain of the HIV Tat protein, has been shown to enhance cell accumulation of various biomolecules. PURPOSE: The influence of Tat, as a cationic carrier, on the accumulation in cell culture of anionic antisense DNAs bound electrostatically rather than covalently was investigated. To establish specificity of the accumulation, antisense DNA and control sequence were studied along with four different peptides. The technique of in situ reverse transcription was used to assay the in vivo hybridization of antisense DNA to the target mRNA in cultured live cells when transducted with the Tat peptide. METHODS: Uniform phosphorothioated DNAs were radiolabeled with 99mTc via Hynic/tricine. This 18 mer antisense DNA against RI alpha mRNA along with its sense and random control was studied in ACHN cells with the four peptides as carriers. RESULTS: The addition of Tat significantly increased cell accumulations. At 12 hours accumulations went from 14% to 45% for the antisense DNA and from 4% to 12% for control. Furthermore, an antisense effect was again suggested, now with the Tat carrier, by the significantly higher accumulation of 99mTc on both antisense DNAs vs. controls. Moreover, the accumulated antisense DNA enhanced with the Tat carrier was capable of priming reverse transcription as determined by an in situ assay suggesting that the DNA could escape from entrapment in endosome or lysosome vesicles for hybridization. However, differences in cellular accumulation with either Tat compared to either scrambled peptide were not significant, showing that the Tat in this study was functioning merely as a cationic carrier. CONCLUSIONS: Although electrostatic binding of antisense DNA to Tat is convenient, the association may mask the unique transduction properties of the peptide. Nevertheless, a promising improvement in cellular accumulation of antisense DNA was observed through the use of these carriers. In addition, at least a fraction of the transducted DNA appears to be free of entrapment to hybridize to its mRNA target in live cells.

In vitro and in vivo assessment of 99mTc-UBI specificity for bacteria.

Technetium-99m labeled ubiquicidin peptide 29-41 ((99m)Tc-UBI) is a cationic human antimicrobial peptide fragment that has been shown to bind bacteria in vitro and accumulates at sites of infection in experimental animals. To help determine if (99m)Tc-UBI is bound to the bacterial cell envelope by a simple nonspecific electrostatic interaction, a comparative study of the in vitro binding of (99m)Tc-UBI and two different (99m)Tc labeled cationic peptides ((99m)Tc-Tat-1-Scr and (99m)Tc-Tat-2-Scr) to bacteria and to two tumor cell line (LS174T and ACHN) was performed. The in vivo specificity of (99m)Tc-UBI for infection in mice was also evaluated using dual labels in the same animal and comparing the target/non-target ratio for (67)Ga-citrate and (99m)Tc-UBI at sites of induced infection and sterile inflammation. Under conditions of this study, the in vitro binding of (99m)Tc-UBI, (99m)Tc-Tat-1-Scr and (99m)Tc-Tat-2-Scr to S. aureus was 35, 78 and 87% respectively. While the binding of (99m)Tc-Tat-1-Scr and (99m)Tc-Tat-2-Scr was 37 and 33% to colon tumor cells (LS174T) and 39 and 41% to renal tumor cells (ACHN) respectively, the binding of (99m)Tc-UBI to both cell types was much lower at less than 4%. In vivo studies revealed that there is a significant difference (p < 0.05) in the radioactive accumulation of (99m)Tc-UBI between the sites of infection and inflammation compared to (67)Ga-citrate. Thus, (99m)Tc-UBI showed an average infection/inflammation ratio of 2.08 +/- 0.49 compared to 1.14 +/- 0.45 for (67)Ga-citrate. In conclusion, the in vitro and in vivo results provide evidence that a specific mechanism is responsible of the (99m)Tc-UBI bacterial intracellular accumulation.

Radiolabeling morpholinos with 90Y, 111In, 188Re and 99mTc.

UNLABELLED: This laboratory is investigating morpholinos (MORF), a DNA analogue, for radiopharmaceutical applications. While we routinely radiolabel with (99m)Tc, we have now labeled MORFs with (111)In, (188)Re and (90)Y in anticipation of therapeutic studies. METHODS: A 25 mer MORF with a primary amine on the 3' equivalent end attached via a 10 member linker was conjugated with an isothiocyanate backbone derivative of DOTA (for labeling with (111)In and (90)Y) and with NHS-MAG(3) (for labeling with (188)Re and (99m)Tc). The in vitro stability of labeled MORFs were investigated and biodistribution was carried out in normal mice. RESULTS: As evident by size exclusion HPLC, ITLC and Sep-Pak analysis, all four radiolabeled MORFs were successfully radiolabeled. In each case, the labeled MORFs showed one sharp peak in HPLC that shifted completely to earlier retention times following addition of a polymer conjugated with the complementary MORF. In saline at room temperature and in 37 degrees C serum, the radioactivity profile of (111)In, (188)Re and (99m)Tc was unchanged over 48 h while over the same period, the (90)Y profile showed a pronounced lower molecular weight peak which did not shift and was shown to be most probably due to (90)Y-DOTA resulting from radiolysis. In addition, the recovery of (188)Re on HPLC decreased as samples aged probably due to oxidation to perrhenate which was retained by the HPLC column. The biodistributions at 1, 3 and 6 h in normal mice showed no important differences among all four labels with the exception that levels of radioactivity in stomach and thyroid were higher in the case of (188)Re due to in vivo oxidation of the radiolabel to perrhenate. CONCLUSIONS: When radiolabeled with DOTA, (90)Y-labeled MORF showed increased instabilities relative to that of (111)In and when radiolabeled with MAG(3), (188)Re showed in vitro and in vivo instabilities compared to (99m)Tc, but all labels were still largely intact after 48 h in saline or serum. Possibly because of the rapid clearance of MORFs, no important differences in biodistribution among (90)Y, (111)In and (99m)Tc labels were evident in normal mice. These strategies for labeling MORF with (90)Y and (188)Re therefore appear to be suitable for therapeutic applications although both show some evidence of instabilities.