[Clinical application of retrosigmoid approach for BONEBRIDGE implantation after auricle reconstruction using expanded postauricular flap].

Objective: To explore the safety and reliability of retrosigmoid approach BONEBRIDGE implantation in patients with auricle reconstruction using skin expansion flap. Methods: A retrospective analysis was conducted on 43 congenital aural atresia cases (43 ears) who underwent BONEBRIDGE implantation from September 2019 to January 2023 in Beijing Tongren Hospital. 30 males and 13 females were included in this work. The implantation age was 9-36 years old (median age=10 y/o). All cases underwent auricle reconstruction surgery using the posterior ear flap expansion method, with 36 cases using the single expanded postauricular flap method and 7 cases using two-flap method. BONEBRIDGE implant surgery was performed during the third stage of auricle reconstruction or after all stages. The hearing improvements were evaluated by comparing the changes in pure tone hearing threshold and speech recognition rate of patients before and after BONEBRIDGE implantation. Routine follow-up was conducted to observe the hearing results and complications. SPSS 14.0 software was applied for data statistical analysis. Results: All 43 patients healed well and had no surgical complications when discharge. The average bone conduction hearing threshold after surgery was (8.2±6.6) dBHL, and there was no statistically significant difference compared to the preoperative [(8.1±5.7) dBHL] (P=0.95). After surgery, the threshold of hearing assistance with power on was significantly lower than that without hearing assistance [(32.8±4.6) dBHL vs (60.5±5.5) dBHL], and the difference was statistically significant (P<0.001). The speech recognition rate of monosyllable words, disyllabic words and short sentences in quiet environment increased to 72%, 84%, and 98% respectively. The differences were statistically significant (P<0.001). The speech recognition rate of monosyllabic words, disyllabic words, and short sentences in noise environment was significantly increased by 70%, 80%, and 92% respectively (P<0.001). After a follow-up of 4 to 47 months (median=24 months), the hearing results were stable and the aesthetic outcomes were satisfying. One patient had delayed hematoma around coil of the implant. After aspiration and compressed dressing for one week, hematoma was not recurrent. Conclusion: For patients after auricle reconstruction using expanded postauricular flap, the preference of retrosigmoid approach is a good choice in terms of safety and reliability of operation, as well as aesthetic appearance.

[Evaluation of adhesive bone conduction hearing aid in pediatric patients with unilateral congenital aural atresia].

Objective: To evaluate the auditory efficacy and subjective satisfaction of adhesive bone conduction hearing aid in children with unilateral congenital aural atresia (UCAA). Methods: Ten subjects (5 males and 5 females) diagnosed with UCAA with an average age of 8.3 years old (ranged from 5 to 15) were included in Beijing Tongren Hospital, Capital Medical University from January to August 2019. The free sound field hearing threshold, word recognition score in quiet, speech reception threshold in noise and sound localization ability (results were measured by RMS error) tests were performed in unaided and aided situation, respectively. Subjective satisfaction questionnaires were also distributed to subjects. Paired t test and Wilcoxon signed rank test were used as statistical analysis methods. Results: The average hearing threshold in aided condition was improved by (21.9±4.4) dB (t=15.8，P<0.05). Speech recognition abilities were generally improved both under quiet and noise (P<0.05);however, when the binaural summation, squelch and head shadow effects were analyzed respectively, the binaural squelch effect was not statistically improved (P>0.05), while the other effects were improved in aided condition (P<0.05). In sound localization test, there was no significant difference of the RMS error value between the unaided and aided situation (P>0.05). The subjects got high satisfaction rates in three subjective questionnaires. Conclusion: The adhesive bone conduction hearing aid can provide significant audiological benefit for children with UCAA as well as raising the quality of their life.

[Effect of γ-secretase inhibitor on middle ear ultrastructures in ovalbumin-mediated otitis media with effusion in rats].

Objective: To study the effect of the inhibitor of Notch signaling pathway-γ-secretase inhibitor DAPT on the ultrastructures of middle ear in the ovalbumin (OVA)-mediated allergic OME in vivo. Methods: Male Sprague-Dawley (SD) rats, weighing 250-300 g, were completely and randomly divided into three groups (5 rats, 10 ears in each group):(1)Control group(2)OME group(3)OME+DAPT group. Rats in the OME group underwent systemic and local sensitization by intraperitoneal and intratympanic injection of ovalbumin to make the model of OVA-induced OME. Rats in the control group were sensitized with PBS. On the basis of establishing the OME model, OME+DAPT group were intraperitoneal injected with DAPT (10 mg/kg) for seven consecutive days and were administered before intratympanic injection of ovalbumin. After the model was successfully established, endoscopy,H&E staining and scanning electron microscopy were used to study the histology and mucous-ciliary ultrastructures of the non-ciliated and ciliated mucosa in the middle ear of each group. One-way ANOVA and Tukey methods were used for statistical analysis. Results: H&E staining showed that the three groups had statistically significant differences in submucosal thickness both in non-ciliated and ciliated regions (non-ciliated area:(6.83±1.47)µm, (38.58±9.57)µm, (32.17±11.89)µm, respectively. F=107.9;cilia area:(26.69±3.22)µm, (30.41±6.75)µm, (26.76±4.06)µm, respectively. F=5.62,both P<0.01). The thickness of the submucosa in the non-ciliated area and the cilia area of the OME group were significantly thicker than that of control group (F=42.08 and 4.40,both P<0.05); the thickness of the non-ciliated area and the ciliated area in OME+DAPT group were reduced compared to OME group(F=1.55 and 2.77,both P<0.05). Scanning electron microscopy showed that the array of cilia on the middle ear mucosa was disorderly arranged and inversed, this phenomenon was relieved in the OME+DAPT group. The number of goblet cells in the control group, OME group, and OME+DAPT group were 9.87±1.92; 15.67±5.77; 10.33±1.99 respectively and the difference between them was statistically significant (F=11.43, P<0.01). The number of goblet cells in the OME group were significantly higher than those in the control group (F=9.00,P<0.01) and the number of goblet cells in the OME+DAPT group were decreased compared to those of OME group (F=8.41, P<0.01). Conclusions: The study demonstrates the pathological changes of the ultrastructure in middle ear in OVA-induced OME and the effect of the γ-secretase inhibitor on it. In OME group, the cilia are disorderly arranged and inversed, the number of goblet cell is increased and they are swelled which suggest the hypersecretion of the mucus. DAPT can regulate OVA-induced allergic inflammation and relieve pathological changes of ultrastructure in middle ear mucociliary transport system through alleviating submucosal inflammation, reducing the hypersecretion of goblet cell and the morphological damage of cilia through the Notch signaling pathway.

[Bonebridge implantation combined with simultaneous bilateral auricle reconstruction for bilateral congenital aural atresia].

Objective: To investigate the feasibility and safety of auricle reconstruction combined with Bonebridge implantation for bilateral aural atresia patients. Methods: A retrospective analysis was conducted for 36 cases(72 ears) who underwent Bonebridge implantation combined with bilateral auricle reconstruction from February 1, 2017 to January 15, 2020. All cases were bilateral congenital aural atresia and underwent Nagata auricle reconstruction for both sides simultaneously. Bonebridge implantations were performed during the second stage of auricle reconstruction. Results: All 36 patients healed well and had no surgical complications when discharged. The preoperative average bone conduction threshold of the patients was(8.5±5.8) dB HL and postoperative bone conduction threshold was (8.4±5.2) dB HL. There was no significant change after the implantation (P=0.724). The preoperative average air conduction threshold of was(64.9±7.4)dB HL and postoperative air conduction threshold was (24.0±5.3) dB HL, which had a significant change after the implantation (P<0.001). The hearing threshold with Bonebridge significantly decreased by 40.9 dB HL compared with the preoperative air conduction threshold(P<0.001). The speech recognition rate of monosyllable words, disyllabic words and short sentences in quiet environment increased by 62.5%, 63.5% and 72.2% respectively. The differences were statistically significant (P<0.001). The speech recognition rate of monosyllabic words, disyllabic words and short sentences in noise environment were significantly increased by 55.9%, 58.9% and 69.9% respectively (P<0.001). After a follow-up of 18.3 months in average, the hearing results were stable and the aesthetic outcomes were satisfied. One patient had implant rupture and healed after revision surgery. Conclusions: With an integrated surgical procedure, patients with bilateral congenital aural atresia can complete bilateral auricle reconstruction and hearing implantation within six months. This integrated surgical procedure is safe and efficient, with a stable hearing improvement and good appearance.

[Congenital microtia with aural atresia or stenosis accompany with first branchial cleft anomaly: report of 5 cases].

Objective: To summarize the experience of the diagnosis, treatment and effects of the cases with coexistence of first branchial cleft anomaly(FBCA) and microtia with congenital aural atresia or stenosis(external auditory canal stenosis, EACS). Method: This was a retrospective study. The clinical data of 5 patients with microtia and EACS in Beijing Tongren Hospital of Capital Medical University from October 2015 to March 2018 were collected, including 3 males and 2 females, aged from 5 to 28 years. The clinical characteristics, imaging findings, treatment methods and effects of 5 patients were analyzed. Result: The 5 cases were all coexistence of EACS and FBCA, three of who associated with cholesteatoma of external auditory canal. CT showed external auditory canal stenosis with soft tissue shadow, sometimes gas or bone septum found inside, filling in the external auditory canal, combined with canal bone destruction irregularly. All patients underwent surgical resection of FBCA, 3 patients accompanied by cholesteatoma resection and canalplasty. The postoperative follow-up ranged from 10 to 39 months, and no recurrence of infection was observed. Conclusions: EACS and FBCA both result from maldevelopment of the first branchial cleft. These two malformations, FBCA and EACS with or without cholesteatoma, can occur simultaneously, in which situation CT shows external auditory canal stenosis with soft tissue shadow inside. These patients underwent surgical resection of FBCA combined with cholesteatoma resection with good result.

Eco-friendly luminescent solar concentrators with low reabsorption losses and resistance to concentration quenching based on aqueous-solution-processed thiolate-gold nanoclusters.

Heavy-metal-containing quantum dots (QDs) with engineered electronic states have been served as luminophores in luminescent solar concentrators (LSCs) with impressive optical efficiency. Unfortunately, those QDs involve toxic elements and need to be synthesized in a hazardous solvent. Recently, biocompatible, eco-friendly gold nanoclusters (AuNCs), which can be directly synthesized in an aqueous solution, have gained much attention for promising applications in 'green photonics'. Here, we explored the solid-state photophysical properties of aqueous-solution-processed, glutathione-stabilized gold nanoclusters (GSH-AuNCs) with a ligand-to-metal charge-transfer (LMCT) state for developing 'green' LSCs. We found that such GSH-AuNCs exhibit a large Stokes shift with almost no spectral overlap between the optical absorption and PL emission due to the LMCT states, thus, suppressing reabsorption losses. Compared with GSH-AuNCs in solution, the photoluminescence quantum yields (PL-QYs) of the LSCs can be enhanced, accompanied with a lengthened PL lifetime owing to the suppression of non-radiative recombination rates. In addition, the LSCs do not suffer from severe concentration-induced PL quenching, which is a common weakness for conventional luminophores. As a result, a common trade-off between light-harvesting efficiency and solid-state PL-QYs can be bypassed due to nearly-zero spectral overlap integral between the optical absorption and PL emission. We expect that GSH-AuNCs hold great promise for serving as luminophores for 'green' LSCs by further enhancing solid-state PL-QYs.

[The treatment efficiency of a new ear moding device in the infants with congenital ear abnormalities].

Objective:To observe the nonsurgical treatment effciency of a new ear moding device on congenital auricle deformities in order to promote clinical application. Method:Twenty-nine patients (38 ears) from Beijing Tongren Hospital Outpatient received ear molding treatment using the EarWell Infant Ear Correction System. We keep regular follow-up and close observation during the moding period. The treatment effciency was judged by the otologist, plastic surgeons and parents based on the preprocedure and postprocedure photographs and divided into 3 grades: excellent, good and poor. Result:Twenty-nine patients (38 ears) including prominent ear, 2 ears; cup ear,7 ears; lidding/lop ear deformities, 4 ears; Stahl's ear, 4 ears; helical rim abnormalities, 4 ears; conchal crus ear, 3 ears, mixed ear deformities 4 ears; cryptotia, 5 ears; ear malformation, 5 ears, 2 patients (2 ears) stop moding after 3 days treatment due to the low compliance of the infants, the remaining 36 ears received ear molding all have improved. The success rate of the EarWell Infant Ear Correction System is more than 94% (good to excellent). Conclusion:EarWell Infant Ear Correction System have a significant moding effect and can achieve satisfactory results in early time. EarWell system has a high success rate in the treatment of neonatal auricle deformations and mild auricle malformations, depending on the severity of the deformations and the initiation of treatment time. The sooner the noninvasive moding begins (especially within one week after birth), the better effect and the shorter treatment time the patients will achieve.

Bovine lactoferricin B induces apoptosis of human gastric cancer cell line AGS by inhibition of autophagy at a late stage.

Gastric cancer is one of the most common malignant cancers, with poor prognosis and high mortality rates worldwide. Therefore, development of an effective therapeutic method without side effects is an urgent need. It has been reported that cationic antimicrobial peptides can selectively bind to negatively charged prokaryotic and cancer cell membranes and exert cytotoxicity without causing severe drug resistance. In the current study, we prepared a series of peptide fragments derived from bovine lactoferrin and evaluated their anticancer potency toward the gastric cancer cell line AGS. Cell viability assay revealed that a 25-AA peptide fragment, lactoferricin B25 (LFcinB25), exhibited the most potent anticancer capability against AGS cells. Lactoferricin B25 selectively inhibited AGS cell growth in a dose-dependent manner, exhibiting a half-maximal inhibitory concentration (IC50) value of 64 µM. Flow cytometry showed a notable increment of the sub-G1 populations of the cell cycle, indicating the induction of apoptosis by LFcinB25. Western blot analysis further revealed that upon LFcinB25 treatment for 2 to 6h, apoptosis-related caspases-3, 7, 8, 9, and poly(ADP-ribose) polymerase (PARP) were cleaved and activated, whereas autophagy-related LC3-II and beclin-1 were concomitantly increased. Thus, both apoptosis and autophagy are involved in the early stage of LFcinB25-induced cell death of AGS cells. However, upon treatment with LFcinB25 for 12 to 24h, LC3-II began to decrease, whereas cleaved beclin-1 increased in a time-dependent manner, suggesting that consecutive activation of caspases cleaved beclin-1 to inhibit autophagy, thus enhancing apoptosis at the final stage. These findings provide support for future application of LFcinB25 as a potential therapeutic agent for gastric cancer.

Allergic conjunctivitis renders CD4(+) T cells resistant to t regulatory cells and exacerbates corneal allograft rejection.

Allergic diseases rob corneal allografts of immune privilege and increase immune rejection. Corneal allograft rejection in BALB/c allergic hosts was analyzed using a short ragweed (SWR) pollen model of allergic conjunctivitis. Allergic conjunctivitis did not induce exaggerated T-cell responses to donor C57BL/6 (B6) alloantigens or stimulate cytotoxic T lymphocyte (CTL) responses. Allergic conjunctivitis did affect T regulatory cells (Tregs) that support graft survival. Exogenous IL-4, but not IL-5 or IL-13, prevented Treg suppression of CD4(+) effector T cells isolated from naïve mice. However, mice with allergic conjunctivitis developed Tregs that suppressed CD4(+) effector T-cell proliferation. In addition, IL-4 did not inhibit Treg suppression of IL-4Rα(-/-) CD4(+) T-cell responses, suggesting that IL-4 rendered effector T cells resistant to Tregs. SRW-sensitized IL-4Rα(-/-) mice displayed the same 50% graft survival as nonallergic WT mice, that was significantly less than the 100% rejection that occurred in allergic WT hosts, supporting the role of IL-4 in the abrogation of immune privilege. Moreover, exacerbation of corneal allograft rejection in allergic mice was reversed by administering anti-IL-4 antibody. Thus, allergy-induced exacerbation of corneal graft rejection is due to the production of IL-4, which renders effector T cells resistant to Treg suppression of alloimmune responses.

Antimicrobial potential for the combination of bovine lactoferrin or its hydrolysate with lactoferrin-resistant probiotics against foodborne pathogens.

Previous reports have shown that several probiotic strains can resist the antibacterial activity of bovine lactoferrin (bLf), but the results are inconsistent. Moreover, a portion of orally administered apo-bLf is digested in vivo by pepsin to yield bLf hydrolysate, which produces stronger antibacterial activity than that observed with apo-bLf. However, whether bLf hydrolysate affects the growth of probiotic strains is unclear. Therefore, various probiotic strains in Taiwan were collected and evaluated for activity against apo-bLf and bLf hydrolysate in vitro. Thirteen probiotic strains were evaluated, and the growth of Lactobacillus acidophilus ATCC 4356, Lactobacillus salivarius ATCC 11741, Lactobacillus rhamnosus ATCC 53103, Bifidobacterium longum ATCC 15707, and Bifidobacterium lactis BCRC 17394 were inhibited by both apo-bLf and bLf hydrolysate. The growth of 8 strains were not affected by apo-bLf and bLf hydrolysate, including L. rhamnosus ATCC 7469, Lactobacillus reuteri ATCC 23272, Lactobacillus fermentum ATCC 11739, Lactobacillus coryniformis ATCC 25602, L. acidophilus BCRC 14065, Bifidobacterium infantis ATCC 15697, Bifidobacterium bifidum ATCC 29521, and Pediococcus acidilactici ATCC 8081. However, apo-bLf and its hydrolysate inhibited the growth of foodborne pathogens, including Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Enterococcus faecalis. Moreover, the supernatants produced by L. fermentum, B. lactis, and B. longum inhibited the growth of most pathogens. Importantly, a combination of apo-bLf or bLf hydrolysate with the supernatants of cultures of the organisms described above showed synergistic or partially synergistic effects against the growth of most of the selected pathogens. In conclusion, several probiotic strains are resistant to apo-bLf and bLf hydrolysate, warranting clinical studies to evaluate the antimicrobial potential for the combination of apo-bLf or its hydrolysate with specific probiotics.

Effect of image settings on nuchal translucency thickness measurement by a semi-automated system.

OBJECTIVE: To investigate whether pre- and post-processing image settings affect NT measurements made by a semi-automatic method (SAM). METHODS: Different image settings (e.g. gain) were either adjusted one at a time on images that had been obtained during fetal NT scans (post-processing, n = 66), or adjusted one at a time during live scanning and image acquisition of the adult posterior tibial artery (pre-processing group, n = 91). The NT and luminal diameter of the posterior tibial artery, respectively, were measured by SAM on all original and adjusted images. RESULTS: Alteration of the image settings resulted in a statistically significant effect on the measurements taken by SAM, with an average pair difference ranging from 0.001 mm to 0.139 mm. Most of the differences were small and therefore the clinical impact would be negligible. The pair differences were greatest with a very high contrast setting, or without tissue harmonic imaging (THI); the paired difference in measurement in those with vs those without THI was more than 0.1 mm in over 40% of cases. CONCLUSIONS: Measurements made by SAM are affected by image settings.

Stabilization of blood methylmalonic acid level in methylmalonic acidemia after liver transplantation.

Methylmalonic acidemia with complete mutase deficiency (mut(0) type) is an inborn error of metabolism with high mortality and morbidity. LT has been suggested to be a solution to this disease, but elevation of urinary and blood MMA was still observed after LT. In this study, we measured dry blood spot MMA and its precursor propionyl-carnitine (C3-carnitine) for mut(0) patients. The results revealed that when C3-carnitine rose during metabolic stress, MMA rose exponentially (up to 1000 micromol/L) in patients who did not undergo LT. In patients who underwent LT, MMA rose to 100-200 micromol/L when C3-carnitine reached 10-20 micromol/L. However, when C3-carnitine rose further to 40-50 micromol/L, MMA levels just stayed put. Therefore, LT stabilized blood MMA level, though there might be a threshold for blood MMA clearance by the donor liver. This finding should be critical to understand the long-term outcome for LT in methylmalonic acidemia.

Allergic airway hyperreactivity increases the risk for corneal allograft rejection.

Corneal allografts transplanted into hosts with allergic conjunctivitis experience an increased incidence and swifter tempo of immune rejection compared to corneal allografts transplanted to nonallergic hosts. Previous findings suggested that increased risk for rejection was not a local effect produced by an inflamed eye, but was due to perturbation of the systemic immune responses to alloantigens on the corneal allograft. We tested the hypothesis that another allergic disease, airway hyperreactivity (AHR), would also increase the risk for corneal allograft rejection. Induction of AHR with either ovalbumin (OVA) or short ragweed (SRW) extract prior to keratoplasty resulted in a steep increase in the speed and incidence of corneal allograft rejection. Delayed-type hypersensitivity (DTH) responses to corneal alloantigens were closely associated with corneal allograft rejection. However, the deleterious effect of AHR on corneal allograft survival was not reflected in a heightened magnitude of allospecific DTH, cytotoxic T lymphocyte and lymphoproliferative responses to the alloantigens on the corneal allograft. Unlike Th2-based immediate hypersensitivity, CD8+ T-cell-based contact hypersensitivity to oxazolone did not increase the risk for corneal allograft rejection. Thus, Th2-based allergic diseases significantly reduce the immune privilege of the corneal allograft and represent important risk factors for consideration in the atopic patient.

Robust engineered circuit design principles for stochastic biochemical networks with parameter uncertainties and disturbances.

Biochemical regulatory networks including genes, proteins and other regulatory molecules suffer from internal parametrical fluctuations (thermal, transcriptional, and splicing) as well as external noises (environmental and intercellular). Robustness is an essential property of intracellular biochemical regulatory networks to attenuate the effects of internal fluctuation and external noise. In this study, several system control schemes are proposed for the robust circuit control design of stochastic linear and nonlinear biochemical regulatory networks. First, the robust stability of genetic and proteomic regulatory networks is discussed under internal fluctuations. Then, the filtering ability of external noises is analyzed for stochastic biochemical regulatory networks. For the case where a biochemical regulatory network is not sufficiently robust to tolerate internal fluctuation and does not have enough filtering ability to filter the external noise, how to improve the robustness and noise filtering ability of stochastic biochemical regulatory networks by engineered control mechanisms is also proposed via biochemical circuit design. The proposed robust gene circuit design principles have potential applications for robust biosynthetic network design. Finally, two design examples are given in-silico to illustrate the design procedure and to confirm the performance of the proposed robust circuit design method.

The role of target elevation in prey selection by tiger beetles (Carabidae: Cicindela spp.).

The elevation of objects in the visual field has long been recognized as a potential distance cue, but it has been demonstrated to a reasonable extent in only four species: humans, frogs, fiddler crabs and backswimmers. Many tiger beetles hunt in flat, sandy areas, and their eyes show "flat-world" adaptations, such as an extended visual streak of higher acuity that corresponds to the horizon. They are therefore possible candidates for the use of elevation as a cue for distance. We tested this empirically and with simulation. In a behavioral prey selection paradigm, in which starved beetles were presented moving prey-targets having different size, speed and elevation, the beetles showed a strong preference for large targets when these were low in the visual field and a weaker preference for small targets when these were near the horizon. Striking of targets above the horizon was reduced compared to sub-horizontal targets, and lacked the size-elevation interaction. We simulated these empirical results with a model that converted elevation to distance, and used distance to estimate the absolute size of the targets. Simulated strike probability was then determined by the similarity between this absolute size and an independently confirmed preferred prey size. The results of the simulation model matched the empirical data as well as the best statistical model of the behavioral results. While some aspects of the model, and the beetles' behavior, differ from the strict geometry of the "elevation hypothesis", our results nevertheless indicate that tiger beetles use elevation to estimate distance to prey, and that it is therefore one of the determinants of prey selection.

A disposable poly(methylmethacrylate)-based microfluidic module for protein identification by nanoelectrospray ionization-tandem mass spectrometry.

The design, fabrication, and analytical use of a poly(methylmethacrylate) (PMMA)-based microfluidic module for nanoelectrospray ionization-tandem mass spectrometry (nano-ESI-MS/MS) were described. The microfluidic module can be mass-produced at low costs and used as a disposable device to generate nano-ESI-MS/MS signals for protein identification from low amounts of protein samples. Compared with commercially available nanospray capillary tips, the module gave comparable signal quality and also offered advantages in convenience and easiness of operation, permitting repeated usage, and disposability.

Immune privilege is extended, then withdrawn, from allogeneic tumor cell grafts placed in the subretinal space.

PURPOSE: To determine whether the subretinal space can extend immune privilege to allogeneic tumor cell grafts that do not possess their own inherent immune privilege. METHODS: P815 tumor cells were injected into the anterior chamber (AC), the subretinal (SR) space, or subconjunctivally in eyes of BALB/c (allogeneic), SCID (immune incompetent), normal DBA/2 (syngeneic), or DBA/2 mice presensitized with P815 cells transfected with interleukin-12 and B7.1. Tumor growth was observed clinically and histologically for up to 50 days. BALB/c recipients were tested for suppression of DBA/2-specific delayed hypersensitivity and concomitant immunity. The SR space of tumor-containing eyes was assessed for its capacity to support ovalbumin (OVA)-specific anterior chamber associated immune deviation (ACAID). RESULTS: P815 cells injected into the SR space of presensitized and normal DBA/2 and SCID mice grew progressively, resulting eventually in recipient death. Tumor cells injected into the SR space of eyes of BALB/c mice grew progressively until day 14, followed by tumor regression resulting in phthisis bulbi (14/35) or tumor elimination (19/35) with preserved ocular anatomy by day 35. Despite elimination of tumors from the SR space, BALB/c recipients exhibited DBA/2-specific ACAID and concomitant immunity. In addition, OVA injected into the SR space of eyes from which tumor has been eliminated induced ACAID. CONCLUSIONS: Various parameters of immune privilege, originally described for the AC, are characteristic of immune privilege within the SR space. However, because P815 cells placed in the AC prove lethal for BALB/c recipients, but P815 cells placed in the SR space resolve without jeopardizing the host's life, immune privilege in the SR space can be distinguished from immune privilege in the AC, and this may have implications for grafts of retinal tissue placed within the SR space.