Partial excision of schwannomatosis with fascicular invasion occurring in the ulnar nerve above the elbow: A 1-year follow-up study.

Although not as common as solitary lesions, multiple schwannomas do occur, even in single nerve lesions. We report a rare case of a 47-year-old female patient who presented with multiple schwannomas with inter-fascicular invasion in the ulnar nerve above the cubital tunnel. Preoperative MRI revealed a 10-cm multilobulated tubular mass along the ulnar nerve above the elbow joint. During excision under 4.5° loupe magnification, we separated three ovoid yellow-colored neurogenic tumors of different sizes, but there were still remaining lesions as it was difficult to completely separate lesions from the ulnar nerve due to the risk of iatrogenic nerve ulnar nerve injury. The operative wound was closed. Postoperative biopsy confirmed the diagnosis of the three schwannomas. During the follow-up, the patient recovered without neurological symptom or limitations in range of motion, and there were no neurological abnormalities. At 1year after surgery, small lesions remained in the most proximal part. However, the patient had no clinical symptoms and was satisfied with the surgical results. Although a long-term follow-up is necessary for this patient, we were able to obtain good clinical and radiological results.

[Expression of LIAS and NRF2 in PBMCs from patients with silicosis and their correlation with silicosis].

Objective: To investigate the expression of lipoic acid synthase gene (LIAS) and nuclear factor-erythroid 2-related factor 2 gene (NRF2) in peripheral blood mononuclear cells (PBMCs) from patients with silicosis and their correlation with silicosis. Methods: A total of 45 healthy controls and 107 patients with silicosis were randomly selected in this study in May 2019. PBMCs were isolated from peripheral blood and NRF2 protein expression was detected by immunofluorescence. The mRNA levels of LIAS and NRF2 in PBMCs were determined by real-time PCR. The dose-response relationship beween LIAS and NRF2 mRNA expression levels and their association with silicosis were analyzed by restricted cubic spline (RCS) and logistic regression. Results: Compared with the control group, the number of monocytes in the case group was significantly increased, and the forced expiratory volume in the first second (FEV(1.0)) decreased, the difference was statistically significant (P<0.05) . The positive expression rate of NRF2 in PBMCs of silicosis patients in stage Ⅰ group was significantly higher than that in the control group, and the positive expression rate of NRF2 in silicosis patients in stageⅡ and Ⅲ groups was lower than that in silicosis patients in control group and stage Ⅰ group (P<0.01) . Results of RCS showed that there was a linear dose-response relationship between LIAS and NRF2 mRNA expression (overall correlation test, χ(2)=213.710, P<0.01; non-linear test, χ(2)=1.340, P=0.511) . There was a positive correlation between mRNA expression of LIAS and that of NRF2 (r=0.651, P<0.01) . The results of multivariate analysis showed that LIAS and NRF2 were increased the risk of incidence in silicosis patients with stageⅠ (OR=11.184, 4.332, P<0.05) and NRF2 was the protective factor in silicosis patients with stage Ⅱ and Ⅲ (OR=0.225, 0.208, P<0.05) after adjusting for potential confounding factors including age, education level, BMI and smoking. Conclusion: There is a linear dose-response relationship between the expression of LIAS and NRF2 mRNA in PBMCs of silicosis patients, LIAS and NRF2 are involved in the pathogenesis of silicosis.

A comparison between McGrath MAC videolaryngoscopy and Macintosh laryngoscopy in children.

BACKGROUND: This prospective, randomised, controlled study was performed to evaluate the usefulness of the McGrath VL compared with Macintosh laryngoscopy in children with expected normal airway during endotracheal intubation, by comparing the time to intubation and difficulty of intubation. METHODS: Eighty-four patients aged 1-10 years who underwent endotracheal intubation for elective surgery were randomly assigned to the McGrath group (n = 42) or the Macintosh group (n = 42). Anaesthesia was induced with 2.5-3.0 mg/kg of propofol and sevoflurane 5-8 vol%. Orotracheal intubation was performed 2 min after injection of rocuronium 0.6 mg/kg with McGrath VL or Macintosh laryngoscope; the primary outcome was the time to intubation. The Cormack and Lehane glottic grade, intubation difficulty score (IDS), and success rate on intubation were assessed. Haemodynamic changes were also recorded. RESULTS: As the primary outcome, median time to intubation [interquartile range] did not differ between the McGrath group and the Macintosh group (25.0 [22.8-28.3] s vs. 26.0 [24.0-29.0] s, P = 0.301). The incidence of grade I glottic view was significantly higher in the McGrath group than in the Macintosh group (95% vs. 74%, P = 0.013). Median IDS was lower in the McGrath group than in the Macintosh group (0 [0-0] vs. 0 [0-1], P = 0.018). There were no significant differences in success rate on intubation or haemodynamics between the two groups. CONCLUSIONS: McGrath VL provides better laryngeal views and lower IDS but similar intubation times and success rates compared with the Macintosh laryngoscope in children with normal airway.

Effects of scalp nerve block on pain and emergence agitation after paediatric nevus surgery: a clinical trial.

BACKGROUND: Pain is considered as being one cause of post-operative emergence agitation (EA) from sevoflurane anaesthesia. The purpose of this study was to investigate the pure effect of post-operative pain on EA after sevoflurane anaesthesia in preschool children undergoing excision of scalp nevi. METHODS: Forty-four children, 1-7 years old, undergoing scalp nevus excision were enrolled. Patients were randomly assigned to two groups: the remifentanil group received single intravenous injection of short-acting synthetic opioid, remifentanil 1 µg/kg just before the scalp incision, and the block group received scalp nerve block with 0.25% ropivacaine after intubation. The end-tidal sevoflurane concentration was maintained around 1.5 vol% unless the mean arterial pressure is out of ±20% range of preoperative values during surgery in both groups. Watcha behaviour scale for EA and face, legs, activity, cry, consolability (FLACC) scale scores for pain were recorded post-operatively. RESULTS: There was no difference in end-tidal sevoflurane concentration between the two groups during surgery and the emergence period. Agitation incidence and scores were not different between the two groups during the recovery period. FLACC scale was significantly lower in the block group than in the remifentanil group at post-anaesthesia care unit (PACU) arrival, at 10 and 20 min after PACU arrival, respectively. CONCLUSION: The scalp nerve block decreased the early post-operative pain after paediatric nevus excision, but it did not decrease the incidence of EA with sevoflurane anaesthesia.

Spontaneous breathing trials after prolonged mechanical ventilation monitored by electrical impedance tomography: an observational study.

BACKGROUND: The study objective was to examine the correlation between regional ventilation distribution measured with electrical impedance tomography (EIT) and weaning outcomes during spontaneous breathing trial (SBT). METHODS: Fifteen patients received 100% automatic tube compensation (ATC) during the first and 70% during the second hour. Another 15 patients received external continuous positive airway pressure (CPAP) of 5 and 7.5 cmH2 O during the first and second hours, respectively. Regional ventilation distributions were monitored with EIT. RESULTS: Tidal volume and tidal variation of impedance correlated significantly during assist-control ventilation and ATC in all patients (r2 = 0.80 ± 0.18, P < 0.001). Higher support levels resulted in similar ventilation distribution and tidal volume, but higher end-expiratory lung impedance (EELI) (P < 0.05). Analysis of regional intratidal gas distribution revealed a redistribution of ventilation towards dorsal regions with lower support level in 13 of 30 patients. These patients had a higher weaning success rate (only 1 of 13 patients failed). Eight of 17 other patient failed (P < 0.05). The number of SBT days needed for weaning was significantly lower in the former group of 13 patients (13.1 ± 4.0 vs. 20.9 ± 11.2 days, P < 0.05). CONCLUSIONS: Regional ventilation distribution patterns during inspiration were associated with weaning outcomes, and they may be used to predict the success of extubation.

Effect of head lift exercise on kinematic motion of the hyolaryngeal complex and aspiration in patients with dysphagic stroke.

The head lift exercise (HLE) is a head-raising workout performed in a supine position. This exercise facilitates activation of the submental muscles located above the hyoid bone in front of the neck. HLE is a potential method to improve the movement of the hyolaryngeal movement and swallowing functions. The purpose of this study was to investigate the effect of HLE on the hyolaryngeal movement and aspiration in patients with dysphagic stroke. A total of 27 patients with stroke were randomly assigned either into the experimental (n = 13) or the control group (n = 14). The experimental group performed HLE 5 days a week for 4 weeks (a total of 20 sessions). Both groups received the same conventional dysphagia therapy. Two-dimensional analysis of the hyolaryngeal movement was carried out using Image J program based on a videofluoroscopic swallowing study. Penetration-aspiration was assessed using Penetration-Aspiration Scale (PAS). The experimental group showed a significant increase in the only superior movements of the hyoid bone compared with the control group (P = 0·033). Aspiration in liquid also exhibited a significant decrease in the experimental group compared with the control group (P = 0·044). Findings from this study confirmed that HLE is an effective intervention to improve hyoid movement and decrease aspiration.

Tongue-to-palate resistance training improves tongue strength and oropharyngeal swallowing function in subacute stroke survivors with dysphagia.

Tongue function can affect both the oral and pharyngeal stages of the swallowing process, and proper tongue strength is vital for safe oropharyngeal swallowing. This trial investigated the effect of tongue-to-palate resistance training (TPRT) on tongue strength and oropharyngeal swallowing function in stroke with dysphagia patients. This trial was performed using a 4-week, two-group, pre-post-design. Participants were allocated to the experimental group (n = 18) or the control group (n = 17). The experimental group performed TPRT for 4 weeks (5 days per week) and traditional dysphagia therapy, whereas the control group performed traditional dysphagia therapy on the same schedule. Tongue strength was measured using the Iowa Oral Performance Instrument. Swallowing function was measured using the videofluoroscopic dysphagia scale (VDS) and penetration-aspiration scale (PAS) based on a videofluoroscopic swallowing study. Experimental group showed more improved in the tongue strength (both anterior and posterior regions, P = 0·009, 0·015). In addition, the experimental group showed more improved scores on the oral and pharyngeal phase of VDS (P = 0·029, 0·007), but not on the PAS (P = 0·471), compared with the control group. This study demonstrated the effectiveness of TPRT in increasing tongue muscle strength and improving swallowing function in patients with post-stroke dysphagia. Therefore, we recommend TPRT as an easy and simple rehabilitation strategy for improving swallowing in patients with dysphagia.

Effects of expiratory muscle strength training on oropharyngeal dysphagia in subacute stroke patients: a randomised controlled trial.

Expiratory muscle strength training (EMST) involves forcible blowing as a means of generating high expiratory pressure, against adjustable resistance. EMST has recently been introduced as a potential treatment for dysphagia. This study was performed to investigate the effects of EMST on the activity of suprahyoid muscles, aspiration and dietary stages in stroke patients with dysphagia. Twenty-seven stroke patients with dysphagia were randomly divided into two groups. The experimental group performed EMST with a 70% threshold value of maximal expiratory pressure, using an EMST device, 5 days a week for 4 weeks. The placebo group trained with a sham device. The EMST regime involved 5 sets of 5 breaths through the EMST device for a total of 25 breaths per day. Activity in the suprahyoid muscle group was measured using surface electromyography (sEMG). Further, the penetration-aspiration scale (PAS) was used to assess the results of the videofluoroscopic swallowing study (VFSS). In addition, dietary stages were evaluated using the Functional Oral Intake Scale (FOIS). The experimental group exhibited improved suprahyoid muscle group activity and PAS results, when compared to the placebo group. Following intervention, statistical analysis indicated significant differences in measured suprahyoid muscle activity (P = 0·01), liquid PAS outcomes (P = 0·03) and FOIS results (P = 0·06), but not semisolid type PAS outcomes (P = 0·32), between the groups. This study confirms EMST as an effective treatment for the development of suprahyoid muscle activity in stroke patients with dysphagia. Additionally, improvements in aspiration and penetration outcomes were observed.

Potent antitumor activity of Oct4 and hypoxia dual-regulated oncolytic adenovirus against bladder cancer.

Most solid tumors undergo hypoxia, leading to rapid cell division, metastasis and expansion of a cell population with hallmarks of cancer stem cells (CSCs). Tumor-selective replication of oncolytic adenoviruses may be hindered by oxygen deprivation in tumors. It is desirable to develop a potent oncolytic adenovirus, retaining its antitumor activity even in a hypoxic environment. We have previously generated an Oct4-dependent oncolytic adenovirus, namely Ad9OC, driven by nine copies of the Oct4 response element (ORE) for specifically killing Oct4-overexpressing bladder tumors. Here, we developed a novel Oct4 and hypoxia dual-regulated oncolytic adenovirus, designated AdLCY, driven by both hypoxia response element (HRE) and ORE. We showed that hypoxia-inducible factor (HIF)-2α and Oct4 were frequently overexpressed in hypoxic bladder cancer cells, and HIF-2α was involved in HRE-dependent and Oct4 transactivation. AdLCY exhibited higher cytolytic activities than Ad9OC against hypoxic bladder cancer cells, while sparing normal cells. AdLCY exerted potent antitumor effects in mice bearing human bladder tumor xenografts and syngeneic bladder tumors. It could target hypoxic CD44- and CD133-positive bladder tumor cells. Therefore, AdLCY may have therapeutic potential for targeting hypoxic bladder tumors and CSCs. As Oct4 is expressed in various cancers, AdLCY may be further explored as a broad-spectrum anticancer agent.

A quantitative evaluation method of skin texture affected by skin ageing using replica images of the cheek.

OBJECTIVE: Skin texture is a fine structure of skin surface where the hill and furrow were crossed to form a star shape. This study was performed to establish a quantitative evaluation method of skin texture affected by skin ageing using replica images of the cheek. METHODS: After producing replicas of the left cheek areas of 80 female subjects, representative replica images were chosen to establish six-level facial skin texture index. Using this new index, skin texture of different-aged subjects was visually assessed by multiple examiners. The number of star configurations was also analysed using the same replica images. Other factors contributing to skin texture, such as skin elasticity, roughness, dermal density, moisture and gloss, were also analysed. RESULTS: The concordance between skin texture scores evaluated by three researchers was high (0.896), and there was a high correlation between skin texture score and age (r = 0.642). The number of star configurations showed high correlations with skin texture scores (r = 0.753) and with age (r = 0.776). Skin texture scores were highly correlated with skin roughness and dermal density, but not with moisture, gloss and elasticity. CONCLUSION: This study suggests that visual grading of skin texture score based on new facial skin texture index and quantification of star configurations will be useful in evaluating skin ageing.

Nonoperative management of right colonic diverticulitis using radiologic evaluation.

OBJECTIVE: Although a few reviews have been conducted, nonoperative management may be the mainstay of therapy for uncomplicated right colonic diverticulitis. With increasing use of radiological evaluation for diverticulitis, the status of the disease is becoming more accessible. In this study, clinical outcomes of nonoperative management for right colonic diverticulitis were assessed according to disease status using radiological evaluation. METHOD: From April 2000 to March 2007, 296 patients were admitted for acute right colonic diverticulitis upon first attack and were treated with nonoperative management. The status of diverticulitis was classified using ultrasonography and/or computed tomography as inflamed diverticulum or phlegmon in 276 patients or pericolic abscess in 20 patients. Uncomplicated diverticulitis was defined as inflamed diverticulum or phlegmon. Length of hospital stay, antibiotic use, failure of initial therapy and the incidence of recurrence after nonoperative management were assessed. RESULTS: The mean length of hospital stay and antibiotic use were 6 and 4.7 days respectively. All patients were successfully treated with the initial medical therapy and their hospital stays were uneventful. Of the 276 patients with an uncomplicated diverticulitis, two patients (1%) had a recurrence during follow-up that could be managed nonoperatively. Of the 20 patients with pericolic abscesses, four patients (20%) had a recurrence. One patient underwent laparoscopic ileocolic resection and the other patients were treated nonoperatively. CONCLUSION: Nonoperative management may be the treatment of choice for right colonic diverticulitis with inflamed diverticulum or phlegmon. Diverticulitis with pericolic abscess should be treated with additional care.

Anterior segment ischemia: etiology, assessment, and management.

Anterior segment ischemia (ASI) is a potentially serious but rare complication of strabismus surgery. Among several risk factors, ASI occurs after strabismus surgery because of the nature of the anterior segment circulation. Disinsertion of rectus muscles leads to a decrease in the blood supply to the various anterior segment structures. We report a series of retrospective and prospective studies performed by our group focused on determining the risk of anterior segment ischemia following strabismus surgery, diagnosis, and modifications to surgical techniques to minimize the impact on anterior segment circulation. We found a significant decrease in postoperative anterior segment blood flow when operating vertical rectus muscles. Plication procedures preserve anterior segment circulation, and modifications to the technique allow the performance of adjustable sutures. Small adjustable selective procedures that spare the ciliary vessels have been demonstrated to be effective in patients with vertical and torsional diplopia. Ciliary sparing augmented adjustable transposition surgery decreases the risk of anterior segment ischemia while allowing management of potential post-operative alignment complications. Finally, ocular coherence tomography angiography is a valuable quantitative and qualitative technique to evaluate anterior segment ischemia. Strabismus surgeons should be aware of the risks of anterior segment ischemia when operating vertical rectus muscles. Modifications to standard surgical techniques allow surgeons to perform complex strabismus surgery in patients at risk for anterior segment ischemia.

Cationic lipid:bacterial DNA complexes elicit adaptive cellular immunity in murine intraperitoneal tumor models.

Previous studies with a mycobacterial heat shock protein (hsp-65) have demonstrated some efficacy using cationic liposome-mediated gene transfer in murine i.p. sarcoma models. To further analyze the efficacy of hsp-65 immunotherapy in clinically relevant models of localized cancer, immunocompetent mice bearing i.p. murine mesothelioma were treated with four i.p. doses of a cationic lipid complexed with plasmid DNA (pDNA) containing hsp65, LacZ, or a null plasmid. We observed >90% long-term survival (median survival, 150 days versus approximately 25 days, treated versus saline control, respectively) in a syngeneic, i.p. murine mesothelioma model (AC29). Long-term survivors were observed in all groups treated with lipid complexed with any pDNA. Lipid alone or DNA alone provided no demonstrable survival advantage. In a more aggressive i.p. model of mesothelioma (AB12), we observed >40% long-term survival in groups treated with lipid:pDNA complexes, again irrespective of the transgene. To ask whether these antitumor effects had led to an adaptive immune response against the tumor cell, we rechallenged long-term survivors in both murine models s.c. with the parental tumor cell line. Specific, long-lasting systemic immunity against the tumor was readily demonstrated in both models (AB12 and AC29). Consistent with these results, splenocytes from long-term survivors specifically lysed the parental tumor cell lines. Depleting the CD8+ T-cells from the splenocyte pool eliminated this lytic activity. Lipid:pDNA treatment of athymic, SCID, and SCID/Beige mice bearing a murine i.p. mesothelioma (AC29) resulted in only a slight survival advantage, but there were no long-term survivors. Treatment of immunocompetent mice depleted of specific immune effector cells demonstrated roles for CD8+ and natural killer cells. Although the exact mechanism(s) responsible for these antitumor effects is unclear, the results are consistent with roles for both innate and adaptive immune responses. An initial tumor cell killing stimulated by cationic lipid:pDNA complexes appears to be translated into long-term, systemic immunity against the tumor cell. These results are the first to demonstrate that adaptive immunity against a tumor cell can be induced by the administration of lipid:pDNA complexes. Multiple administrations of cationic lipid complexed with pDNA lacking an expressed transgene could provide a promising generalized immune-mediated modality for treating cancer.

Use of a "replication-restricted" herpes virus to treat experimental human malignant mesothelioma.

Modified, nonneurovirulent herpes simplex viruses (HSVs) have shown promise in the treatment of brain tumors. However, HSV-1 can infect and lyse a wide range of cell types. In this report, we show that HSV-1716, a mutant lacking both copies of the gene coding ICP-34.5, can effectively treat a localized i.p. malignancy. Human malignant mesothelioma cells supported the growth of HSV-1716 and were efficiently lysed in vitro. i.p. injection of HSV-1716 into animals with established tumor nodules reduced tumor burden and significantly prolonged survival in an animal model of non-central nervous system-localized human malignancy without dissemination or persistence after i.p. injection into SCID mice bearing human tumors. These findings suggest that this virus may be efficacious and safe for use in localized human malignancies of nonneuronal origin such as malignant mesothelioma.

'Shadow sign' in congenital hypertrophy of the retinal pigment epithelium of young myopic pigmented patients.

PURPOSE Congenital hypertrophy of the retinal pigment epithelium (CHRPE) may simulate choroidal melanoma in certain cases. We report unique clinical features we have observed in cases of CHRPE in young myopic pigmented patients.METHODS Patients who were referred for evaluation of a suspicious choroidal lesion and found to have a CHRPE lesion with the clinical appearance of lesion elevation and a subretinal fluid-like 'shadow sign' were included. Patient and lesion characteristics were tabulated. Available images, including fundus photography, ultrasonography, optical coherence tomography (OCT), and fluorescein angiography (FA) were reviewed.ResultsSix patients were included. The 'shadow sign' was anterior to the CHRPE lesion in all cases. The mean age of the patients was 27.3 years. The ethnicities of the patients were Chinese (n=1), Hispanic (n=3), or African-American (n=2). Five of six patients were myopic.CONCLUSIONS Although most CHRPE lesions appear flat on ophthalmoscopy, lesions in young myopic patients of pigmented ethnicities may appear elevated with a 'shadow sign' due to 'dark without pressure.' This new finding may be related to the vitreoretinal interface in young myopic pigmented patients and must be distinguished from true subretinal fluid and lesion thickness, which are often observed in choroidal melanoma.

Abdominal Aortic Calcification in Living Kidney Donors.

OBJECTIVE: This study assesses the association between abdominal aortic calcification (AAC) and renal function of living kidney donors and evaluate AAC as a surrogate marker for nephrosclerosis. METHODS: Between January 2010 and March 2013, 287 donors who underwent living donor nephrectomy were enrolled. We analyzed computed tomography angiographies and quantified AAC scores by calculating the Agatston score for the abdominal aorta. The donors were stratified into the non-AAC group (AAC score = 0; n = 238) and the AAC group (AAC score >0; n = 49). The relationship between AAC and perioperative estimated glomerular filtration rate was analyzed. For the 180 donors consenting to implantation biopsy, the nephrosclerosis score was defined as the sum of abnormalities, including glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis. RESULTS: The mean AAC score was 185.5 ± 263.3 in the AAC group. The AAC group was older than the non-AAC group (51.1 ± 6.1 vs 37.9 ± 11 years; P < .001). Perioperative renal function was not different between the 2 groups. However, among the AAC group, donors with an AAC score of >100 were associated with delayed renal function recovery (P = .035). Donors with AAC were more likely to have glomerulosclerosis (50.0% vs 29.1%; P = .022), tubular atrophy (62.5% vs 33.1%; P = .002), and a higher nephrosclerosis score (P = .002). CONCLUSIONS: Living donors with an AAC score of >100 require close observation because they have a higher probability of delayed renal function recovery after donation. AAC is associated with nephrosclerosis in healthy adults.

Developmental stage-dependent self-regulation of embryonic cortical precursor cell survival and differentiation by leukemia inhibitory factor.

Cortical precursor cells secrete soluble factors for their own survival and self-renewal. We show here that neural precursor cells isolated from embryonic rat cortices abundantly secrete leukemia inhibitory factor (LIF) and express its receptor components, gp130 and LIF receptor. LIF signaling is responsible for cortical precursor cell survival. As described previously, LIF caused astrocytic differentiation of cultured embryonic cortical precursor cells. LIF-mediated survival and astrocytic differentiation of cortical precursor cells were differentially regulated, depending on the developmental ages of embryos from which cortical precursors were isolated. LIF did not enhance the survival of cortical precursor cells isolated from later embryos (embryonic day 16, E16). Moreover, LIF-mediated astrocytic differentiation was not observed in early (E12) cortical precursors. Inhibition studies revealed that Janus-activated kinase/signal transducer and activator of transcription and phosphatidylinositol 3 kinase/Akt pathways participate in both the LIF-mediated effects. However, mitogen-activated protein kinase, another signal pathway activated by LIF, was specifically responsible for astrocytic differentiation. These findings collectively indicate that precursor cells self-regulate the sequential processes of brain development, such as early maintenance of the precursor cell population and later differentiation into astrocytes, via common LIF signaling.

Isolation and characterization of four CSF-1-dependent placental macrophage cell lines.

By selection and cloning in the presence of colony-stimulating factor 1 (CSF-1), we have obtained from separate explants of individual 12- or 13-day mouse placentas four clonal cell lines dependent on CSF-1 for survival and growth in culture. All four cell lines show characteristics consistent with their derivation from placental macrophages. We describe the effects of CSF-1 on growth, morphology, and CSF-1 receptor phosphorylation. One cell line, JPL2A, which shows relatively complete growth arrest in the absence of CSF-1, was characterized in detail with respect to the effects of CSF-1 on DNA synthesis and protein turnover and its response to the duration of CSF-1 stimulation. In contrast to previous studies, our results suggest that extended stimulation leads to continuous recruitment of cells competent to reenter the cell cycle. These findings are discussed in terms of growth factor effects on the cell cycle and the usefulness of these cell lines for further study of growth factor signal transduction in macrophages.

Evaluation of an E1E4-deleted adenovirus expressing the herpes simplex thymidine kinase suicide gene in cancer gene therapy.

Studies with first-generation adenoviral vectors have uncovered limitations that include finite transgene persistence, potential hepatotoxicity, and contamination with replication-competent adenovirus (RCA). To address these limitations within the context of cancer suicide gene therapy, a new adenoviral vector was developed containing the herpes simplex virus type 1 thymidine kinase (HSV tk) gene inserted in the E1 region of a recombinant vector containing deletions in the E1 and E4 regions of the Ad5 genome. The HSV tk minigene was placed under transcriptional control of a Rous sarcoma virus (RSV) promoter. This new E1E4-deleted vector was compared with the first-generation E1E3-deleted Ad.RSVtk vector. Generation of replication-competent adenovirus during production was eliminated. Using semiquantitative immunoblotting, the two vectors produced equivalent amounts of the expected 44-kDa tk-encoded protein in three different cell lines tested. The ability of the E1E4-deleted vector to sensitize tumor cells to ganciclovir (GCV) using in vitro assays and mixing studies was comparable to that of the E1E3-deleted vector. In vivo bystander effects were investigated using mixing studies in a syngeneic flank tumor model and demonstrated no difference between vectors in either immunocompetent or immunodeficient mice. To test the efficiency of these vectors in treating tumors in clinically relevant models, virus was injected intraperitoneally into tumor-bearing SCID mice and intrapleurally in a syngeneic rat mesothelioma model. After treatment of animals with ganciclovir, both vectors were roughly equivalent in their ability to increase mean survival (from approximately 40 to approximately 70 days) and markedly reduce tumor burden. Finally, formal toxicology studies were performed and showed similar amounts of local inflammation without systemic toxicity. In summary, this series of in vitro and in vivo experiments indicates that the performance of the recombinant E1E4-deleted adenoviral vector was virtually identical to that of the E1E3-deleted vector. Since the E1E4 vector has a much lower rate of recombination during production and has been shown to be less hepatotoxic in animal models, this new vector should prove superior to the first-generation Ad.HSVtk vectors in clinical cancer gene therapy trials.

The evaluation of adenoviral p53-mediated bystander effect in gene therapy of cancer.

Because many tumors have mutated p53, one potential strategy proposed for cancer gene therapy is the introduction of the wild-type p53 gene into tumor cells. One puzzling aspect of this approach is that currently available gene transfer protocols result in a small percentage of tumor cells being transduced in vivo, thus implicating a "bystander effect" to achieve therapeutic efficacy. Because bystander effects in the context of p53-mediated gene therapy have not been well characterized, we evaluated the role of in vitro and in vivo bystander effects of adenovirally delivered p53 (AdWTp53). Using human tumor cell lines that did not express p53 protein but were infectible with adenovirus and showed sensitivity to p53-mediated apoptosis, we were unable to demonstrate an AdWTp53-mediated in vitro bystander effect, despite seeing strong bystander effects when cells were infected with an adenovirus containing the suicide gene herpes simplex virus thymidine kinase and treated with ganciclovir. In contrast, in vivo flank mixing studies using one of these cell lines showed a weak but significant p53-mediated bystander effect (a 40% inhibition of tumor growth). This bystander effect translated into a small survival advantage in an established intraperitoneal tumor model when tumor burden was low at the time of viral instillation. The survival advantage was lost, however, when tumor burden was increased. This study indicates that treatment of human tumors using AdWTp53 may be possible; however, because of the weak bystander effect in vivo, effective treatment will likely require a large percentage of tumor cells to be transduced.