[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.

Human lung lysozyme: sources and properties

Lysozyme in human airway secretions is thought to defend the lung against airborne bacteria. Although lysozyme has been purified and characterized from human tears, milk, saliva, and other sources (1-5), human lung lysozyme has received little attention except for measurements of concentrations in sputum (6, 7), immunocytochemical and histochemical localization (8-12),and studies of secretion by alveolar macrophages (13). This study was designed to identify the sources of secreted lung lysozyme, to quantitate the secretory activities of the various sources,and to compare the properties of lysozyme from lung cells with those from other tissues.

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.

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.

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.

Genomic cloning of 18 kDa oleosin and detection of triacylglycerols and oleosin isoforms in maturing rice and postgerminative seedlings

Oleosins are hydrophobic proteins localized abundantly in the oil bodies of plant seeds. Two distinct oleosin isoforms of molecular masses 18 and 16 kDa are present in rice oil bodies. These isoforms were found in similar ratio in rice embryos and aleurone layers. To survey potential DNA sequences involved in the activation of oleosin genes, a genomic clone of rice 18 kDa oleosin was sequenced, and its 5'-flanking region was compared with that of the known rice 16 kDa oleosin gene. Corresponding mRNAs of the two rice oleosin isoforms appeared seven days after pollination and vanished in mature seeds. Triacylglycerols and oleosins were accumulated concomitantly in maturing rice reeds in accord with the active assembly of oil bodies, and partly mobilized in postgerminative seedlings. Approximately 60% of the stored triacylglycerols in rice were not utilized: while the majority of oil bodies in embryos were mobilized in five days after imbibition, those in aleurone layers remained intact in postgerminative seedlings.

Uveal melanomas contain antigenically specific and non-specific infiltrating lymphocytes

PURPOSE

Tumor-infiltrating lymphocytes (TIL) were recovered from a series of human choroidal melanomas and expanded in cultures containing interleukin-2 (IL-2) to determine whether TIL contained cytotoxic cells that could be activated in vitro.

METHODS

TIL were recovered from six ocular melanoma patients and expanded in vitro with IL-2. Cytotoxic activity was tested in a standard 4-hr 51Cr release assay. The HLA class I phenotype of patients was determined, using peripheral blood lymphocytes and the Amos modified-cytotoxicity test. HLA class I expression on tumor cells was determined by flow cytometry.

RESULTS

TIL from four patients lysed autologous ocular melanoma cells. Two of these patients possessed TIL that displayed specific cytotoxic activity and failed to lyse tumor cells from other patients (HLA-mismatched, or -matched). TIL from the remaining two patients possessed non-specific cytotoxic cells that lysed ocular melanoma cells from a variety of other patients (HLA-mismatched). TIL from patients that failed to lyse autologous tumor cells possessed cytotoxic activity for ocular melanoma cells from other HLA-mismatched patients.

CONCLUSIONS

Ocular melanomas accumulate lymphocytes with the potential to kill tumor cells. Our results imply that elimination of tumor cells may be possible by activation of cytotoxic cells present within progressively growing ocular tumors.

Gene transfer of the CD80 costimulatory molecule into ocular melanoma cells using a novel episomal vector

PURPOSE

The CD80 (B7.1) molecule, which is a necessary costimulatory signal for T-cell activation and proliferation, is a powerful inducer of antitumor immunity. In this study, primary human ocular melanoma cells were transfected with a novel vector (B45-Neo episomal vector) containing the complementary DNA (cDNA) for human CD80 to determine if this vector system is useful for stimulating CD8+ T cells.

METHODS

Ocular melanoma cells were transfected with the B45-Neo episomal vector containing the cDNA for human CD80 and were positively selected in medium containing geneticin. The transcription of plasmid cDNA, plasmid copy number, and cell surface expression were determined on transfected tumor cell lines, and cloned tumor cells were obtained by limiting dilution techniques. The stability of CD80 expressed on tumor cells was determined after prolonged culture without geneticin and on irradiated cells. Autologous lymphocytes were restimulated with CD80+ tumor cells in the presence of recombinant interleukin-2 to determine whether CD8+ T cells were stimulated.

RESULTS

CD80 was expressed on tumor cells transfected with the B45-Neo vector containing the cDNA for CD80. The level of CD80 expressed on different transfected tumor cell lines was heterogeneous and dependent on the plasmid copy number. High CD80 expression was observed on cloned tumor cells that possessed more than 520 plasmids per cell; intermediate levels were observed on tumor cells with approximately 240 to 520 plasmids. CD80+ ocular melanoma cells maintained a stable CD80 expression even after prolonged culture without geneticin, and on irradiated tumor cells. CD80 expressed on tumor cells was biologically functional and stimulated autologous CD8+ cells.

CONCLUSIONS

The B45-Neo episomal vector induces stable expression of the CD80 costimulatory molecule on ocular melanoma cells. Our results indicate that this vector is suitable for experiments designed to genetically engineer ocular melanoma cells to stimulate CD8+ T cells.

Expression of MAGE genes in ocular melanoma during progression from primary to metastatic disease

Primary melanomas that form within the eye have a unique pattern of disease progression as compared with melanomas that form within the skin. A high percentage of patients (approximately 50%) develop metastatic tumors that occur predominately in the liver. An unusual characteristic of ocular melanomas is the prolonged disease-free interval that extends for many years between the development of primary and metastatic tumors. It is estimated that the shortest interval between dissemination of tumor cells from the eye and the appearance of clinically detectable metastases is 6 years. A recent report indicated that fresh uveal melanoma tissue and metastatic tumor biopsies failed to express melanoma antigen gene (MAGE)-1, MAGE-2, or MAGE-3. In the present study, we examined the expression of MAGE genes on fresh and cultured tumor cells obtained from an ocular melanoma patient during different stages of progressive disease. MAGE gene expression was determined by reverse transcription-polymerase chain reaction using MAGE-1, MAGE-2 and MAGE-3 specific primers. Our results demonstrate that primary ocular tumor tissue and cultured tumor cells both express significant levels of MAGE-1, 2, and 3 at the time of enucleation. A high percentage of tumor cells within the primary tumor appear to express MAGE as demonstrated by consistent MAGE expression in 16 tumor cell clones. Metastatic liver tumors that developed 3 years after enucleation and 18 years after the initial formation of the primary tumor also expressed high levels of MAGE-1, -2, and -3. MAGE was expressed on fresh tumor tissue from a single biopsy and cultured tumor cells obtained from three of four different metastatic tumor nodules. When the MAGE-negative metastatic tumor cells were treated with the demethylating agent 5-Aza-2-Deoxycytidine (5-Aza-dC), transcription of MAGE-1 was restored, indicating the MAGE genes were not deleted. Our results demonstrate that in some patients, MAGE genes are expressed on primary and metastatic ocular melanomas.

Expression of MAGE genes in ocular melanoma cell lines

The pathobiology of melanomas that develop within the eye is distinct from melanomas that develop within the subcutaneous tissues of the skin. This may be related to the unique structural and functional differences between normal melanocytes present within the uveal tract of the eye and the epidermal layers of the skin. The purpose of the present study was to determine whether normal pigmented cells within the eye (melanocytes and retinal pigment epithelial cells) and cultured cells derived from malignant ocular melanomas express the MAGE genes that encode tumor antigens that are recognized by specific CD8+ cytotoxic T lymphocytes. In the present series of experiments, we examined MAGE expression in cultured ocular melanoma cells obtained from a group of 17 ocular melanoma patients. Normal ocular melanocytes and retinal pigment epithelial cells were recovered and cultured from eyes enucleated for trauma. MAGE gene expression was determined using reverse transcription-polymerase chain reaction specific for either MAGE-1, -2, or -3. Our results demonstrate that MAGE-1, MAGE-2, and MAGE-3 genes are transcribed in primary ocular melanoma cell lines and are detected in cells recovered from 41, 53, and 53% of the patients examined, respectively. Normal choroidal melanocytes and retinal pigment epithelial cells did not express MAGE genes. We conclude that cultured ocular melanoma cell lines express MAGE-1, MAGE-2, and MAGE-3 genes.

Therapeutic antitumor response after immunization with a recombinant adenovirus encoding a model tumor-associated antigen

Recombinant adenovirus (rAd), deleted of critical genes that enable viral replication and replaced with genes encoding heterologous proteins, has been shown to be a safe and effective vector in gene therapy studies. To evaluate a potential role for rAd as an immunogen, we used two different replication-defective type 2 rAds encoding the model Ag, beta-galactosidase (beta-gal). To determine whether rAd elicited the kind of immune responses therapeutic in an anti-tumor setting, the beta-gal-expressing adenocarcinoma, CT26.CL25, was used. Splenocytes from BALB/c mice immunized with 1 x 10(7) infectious units (iu) of rAd demonstrated anti-beta-gal activity after in vitro culture with the relevant L(d) beta-gal peptide. Adoptive transfer of these same splenocytes produced dramatic regression of established pulmonary metastases. However, when tumor-bearing mice were treated with 1 x 10(7) iu of rAd, no reduction in established disease was observed even when rAd was given with exogenous IL-2. To increase the viral dose delivered to each animal, we used an E1-E4-deleted rAd that could be grown to much higher titers. Significant reduction occurred with 10-fold more rAd (1 x10(8) iu) was administered. Exogenous IL-2 administration with 1 x 10(8) iu of rAd resulted in augmentation of this anti-tumor effect. These findings demonstrate that when using a nonreplicating virus, the viral dose is directly related to the immune response generated. These data constitute the first reported use of rAd in the treatment of an established experimental cancer and may have implication for the treatment of human cancer.

Therapeutic antitumor response after immunization with a recombinant adenovirus encoding a model tumor-associated antigen

Recombinant adenovirus (rAd), deleted of critical genes that enable viral replication and replaced with genes encoding heterologous proteins, has been shown to be a safe and effective vector in gene therapy studies. To evaluate a potential role for rAd as an immunogen, we used two different replication-defective type 2 rAds encoding the model Ag, beta-galactosidase (beta-gal). To determine whether rAd elicited the kind of immune responses therapeutic in an anti-tumor setting, the beta-gal-expressing adenocarcinoma, CT26.CL25, was used. Splenocytes from BALB/c mice immunized with 1 x 10(7) infectious units (iu) of rAd demonstrated anti-beta-gal activity after in vitro culture with the relevant L(d) beta-gal peptide. Adoptive transfer of these same splenocytes produced dramatic regression of established pulmonary metastases. However, when tumor-bearing mice were treated with 1 x 10(7) iu of rAd, no reduction in established disease was observed even when rAd was given with exogenous IL-2. To increase the viral dose delivered to each animal, we used an E1-E4-deleted rAd that could be grown to much higher titers. Significant reduction occurred with 10-fold more rAd (1 x10(8) iu) was administered. Exogenous IL-2 administration with 1 x 10(8) iu of rAd resulted in augmentation of this anti-tumor effect. These findings demonstrate that when using a nonreplicating virus, the viral dose is directly related to the immune response generated. These data constitute the first reported use of rAd in the treatment of an established experimental cancer and may have implication for the treatment of human cancer.

Anti-tumor activity of cytotoxic T lymphocytes elicited with recombinant and synthetic forms of a model tumor-associated antigen

The recent cloning of tumor-associated antigens (TAAs) recognized by CD8+ T lymphocytes (TCD8+) has made it possible to use recombinant and synthetic forms of TAAs to generate TCD8+ with anti-tumor activity. To explore new therapeutic strategies in a mouse model, we retrovirally transduced the experimental murine tumor CT26(H-2d), with the lacZ gene encoding our model TAA, beta-galactosidase (beta-gal). The transduced cell line, CT26.CL25, grew as rapidly and as lethally as the parental cell line in normal, immunocompetent animals. In an attempt to elicit TCD8+ directed against our model TAA by using purely recombinant and synthetic forms of our model TAA, we synthesized a nine-amino-acid long immunodominant peptide of beta-gal (TPH-PARIGL), corresponding to amino acid residues 876-884, which was known to be presented by the Ld major histocompatibility complex (MHC) class I molecule, and a recombinant vaccinia virus encoding the full-length beta-gal protein (VJS6). Splenocytes obtained from naïve mice and co-cultured with beta-gal peptide could not be expanded in primary ex vivo cultures. However, mice immunized with VJS6, but not with a control recombinant vaccinia virus, yielded splenocytes that were capable of specifically lysing CT26.CL25 in vitro after co-culture with beta-gal peptide. Most significantly, adoptive transfer of these cells could effectively treat mice bearing 3-day-old established pulmonary metastases. These observations show that therapeutic TCD8+ directed against a model TAA could be generated by using purely recombinant and synthetic forms of this antigen. These findings point the way to a potentially useful immunotherapeutic strategy, which has been made possible by the recent cloning of immunogenic TAAs that are expressed by human malignancies.

IL-2 enhances the function of recombinant poxvirus-based vaccines in the treatment of established pulmonary metastases

Neoplastic cells are generally poor immunogens. Transfection of the murine tumor CT-26 with beta-galactosidase (beta-gal), a protein from Escherichia coli, did not alter its growth rate in vivo, or its lethality, and did not elicit a measurable anti-beta-gal immune response. Immunization with beta-gal-expressing recombinant vaccinia viruses (rVV) elicited specific anti-beta-gal cytolytic T lymphocytes, but rVV-beta-gal was only marginally therapeutic when given to tumor-bearing mice. With the aim of expanding the immune response against beta-gal, used here as a model tumor Ag, we gave mice exogenous IL-2 starting 12 h after the poxvirus. The therapeutic effectiveness of the combination of poxvirus and IL-2 was far greater than either of these treatments alone. When the cDNA for IL-2 was inserted into the viral genome of the rVV construct to make a double recombinant (drVV), antitumor activity was further augmented. One mechanism of action may be the enhanced activation or expansion of cytotoxic T cells, because a marked increase in primary cytotoxic responses against vaccinia determinants was observed. Interestingly, other cytokines (mGM-CSF, mTNF-alpha, and mIFN-gamma) inserted into the rVV genome did not modify the efficacy of the rVV constructs. The increase in specific CTL responses against beta-gal by drVV expressing the tumor-associated Ags (TAA) and IL-2 was more pronounced in mice bearing the lacZ-transduced tumor than in those bearing the parental cell line, suggesting that the TAA presented by growing tumor cells can either pre-activate or otherwise amplify the immune response induced by the rVV. Unfortunately, in several long-term surviving mice, tumor recurred that no longer expressed beta-gal. These results indicate that treatment of disseminated tumors by using recombinant viruses expressing TAA can be enhanced by IL-2 provided exogenously, or encoded within the recombinant virus.

IL-2 enhances the function of recombinant poxvirus-based vaccines in the treatment of established pulmonary metastases

Neoplastic cells are generally poor immunogens. Transfection of the murine tumor CT-26 with beta-galactosidase (beta-gal), a protein from Escherichia coli, did not alter its growth rate in vivo, or its lethality, and did not elicit a measurable anti-beta-gal immune response. Immunization with beta-gal-expressing recombinant vaccinia viruses (rVV) elicited specific anti-beta-gal cytolytic T lymphocytes, but rVV-beta-gal was only marginally therapeutic when given to tumor-bearing mice. With the aim of expanding the immune response against beta-gal, used here as a model tumor Ag, we gave mice exogenous IL-2 starting 12 h after the poxvirus. The therapeutic effectiveness of the combination of poxvirus and IL-2 was far greater than either of these treatments alone. When the cDNA for IL-2 was inserted into the viral genome of the rVV construct to make a double recombinant (drVV), antitumor activity was further augmented. One mechanism of action may be the enhanced activation or expansion of cytotoxic T cells, because a marked increase in primary cytotoxic responses against vaccinia determinants was observed. Interestingly, other cytokines (mGM-CSF, mTNF-alpha, and mIFN-gamma) inserted into the rVV genome did not modify the efficacy of the rVV constructs. The increase in specific CTL responses against beta-gal by drVV expressing the tumor-associated Ags (TAA) and IL-2 was more pronounced in mice bearing the lacZ-transduced tumor than in those bearing the parental cell line, suggesting that the TAA presented by growing tumor cells can either pre-activate or otherwise amplify the immune response induced by the rVV. Unfortunately, in several long-term surviving mice, tumor recurred that no longer expressed beta-gal. These results indicate that treatment of disseminated tumors by using recombinant viruses expressing TAA can be enhanced by IL-2 provided exogenously, or encoded within the recombinant virus.

Active immunotherapy of cancer with a nonreplicating recombinant fowlpox virus encoding a model tumor-associated antigen

Some tumor cells express Ags that are potentially recognizable by T lymphocytes and yet do not elicit significant immune responses. To explore new immunotherapeutic strategies aimed at enhancing the recognition of these tumor-associated Ags (TAA), we developed an experimental mouse model consisting of a lethal clone of the BALB/c tumor line CT26 designated CT26.WT, which was transduced with the lacZ gene encoding beta-galactosidase, to create CT26.CL25. The growth rate and lethality of CT26.CL25 and CT26.WT were virtually identical despite the expression by CT26.CL25 of the model tumor Ag in vivo. A recombinant fowlpox virus (rFPV), which is replication incompetent in mammalian cells, was constructed that expressed the model TAA, beta-galactosidase, under the influence of the 40-kDa vaccinia virus early/late promoter. This recombinant, FPV.bg40k, functioned effectively in vivo as an immunogen, eliciting CD8+ T cells that could effectively lyse CT26.CL25 in vitro. FPV.bg40k protected mice from both subcutaneous and intravenous tumor challenge by CT26.CL25, and most surprisingly, mice bearing established 3-day pulmonary metastasis were found to have significant, Ag-specific decreases in tumor burden and prolonged survival after treatment with the rFPV. These observations constitute the first reported use of rFPV in the prevention and treatment of an experimental cancer and suggest that changing the context in which the immune system encounters a TAA can significantly and therapeutically alter the host immune response against cancer.

Active immunotherapy of cancer with a nonreplicating recombinant fowlpox virus encoding a model tumor-associated antigen

Some tumor cells express Ags that are potentially recognizable by T lymphocytes and yet do not elicit significant immune responses. To explore new immunotherapeutic strategies aimed at enhancing the recognition of these tumor-associated Ags (TAA), we developed an experimental mouse model consisting of a lethal clone of the BALB/c tumor line CT26 designated CT26.WT, which was transduced with the lacZ gene encoding beta-galactosidase, to create CT26.CL25. The growth rate and lethality of CT26.CL25 and CT26.WT were virtually identical despite the expression by CT26.CL25 of the model tumor Ag in vivo. A recombinant fowlpox virus (rFPV), which is replication incompetent in mammalian cells, was constructed that expressed the model TAA, beta-galactosidase, under the influence of the 40-kDa vaccinia virus early/late promoter. This recombinant, FPV.bg40k, functioned effectively in vivo as an immunogen, eliciting CD8+ T cells that could effectively lyse CT26.CL25 in vitro. FPV.bg40k protected mice from both subcutaneous and intravenous tumor challenge by CT26.CL25, and most surprisingly, mice bearing established 3-day pulmonary metastasis were found to have significant, Ag-specific decreases in tumor burden and prolonged survival after treatment with the rFPV. These observations constitute the first reported use of rFPV in the prevention and treatment of an experimental cancer and suggest that changing the context in which the immune system encounters a TAA can significantly and therapeutically alter the host immune response against cancer.

ras-induced neoplastic transformation and sensitivity to tumor necrosis factor

Tumor necrosis factor (TNF) is toxic to many tumor cells but not to normal cells. We previously reported that transfection of TNF-resistant C3H10T1/2 fibroblasts with a mutant Ha-ras oncogene induced tumorigenicity as well as TNF sensitivity. To investigate the relationship between tumorigenic transformation and TNF sensitivity, we isolated TNF-resistant revertants from Ha-ras transformed TNF-sensitive cells and analyzed them for p21 expression and tumorigenic potential. The TNF-resistant cells expressed the same amount of mutant p21 as TNF-sensitive cells and retained their tumorigenic potential. In fact, TNF-resistant cells were more tumorigenic than TNF-sensitive cells. These results suggest that mutant p21 expression is directly associated with tumorigenic transformation, while acquisition of TNF sensitivity is incidental to the process of neoplastic transformation. It is possible, however, that ras-induced TNF sensitivity and transformation are regulated by different effector molecules downstream of Ras.

Presentation of endogenous tumor antigens to CD4+ T lymphocytes by murine melanoma cells transfected with major histocompatibility complex class II genes

In a previous study, we demonstrated that K1735 transfectants expressing either Kk or Ak antigens alone produced tumors in syngeneic mice, whereas transfectants that expressed both antigens were rejected. In this study, we investigated whether K1735 transfectants expressing Ak molecules can present endogenous tumor antigens to CD4+ T lymphocytes in the absence of normal accessory cells. Our results indicate that K1735 transfectants expressing Kk and Ak molecules presented antigen to both CD4+ and CD8+ T lymphocytes, whereas K1735 transfectants expressing only the Ak or the Kk antigen preferentially stimulated either CD4+ or CD8+ T cells. Analogous to endogenous antigens, K1735 transfectants expressing Ak molecules also presented exogenous hen egg lysozyme (HEL) to HEL-specific 3A9 hybridomas in the absence of normal accessory cells. These results demonstrate that K1735 murine melanoma cells expressing Ak molecules can function as antigen-presenting cells and that the generation of an effective antitumor immune response by K1735 melanoma cells expressing Kk and Ak antigens is due to their ability to present endogenous tumor antigens to both helper and cytotoxic T cells.

Rejection of K1735 murine melanoma in syngeneic hosts requires expression of MHC class I antigens and either class II antigens or IL-2

Tumor specific immunity is mediated by CTL that recognize peptide Ag in the context of MHC class I molecules and by Th cells that recognize peptide Ag in the context of MHC class II molecules. To clarify the relative importance of MHC class I and II Ag in tumor rejection, we transfected a K1735 melanoma that did not express constitutively either MHC class I or II Ag with H-2Kk and/or I-Ak genes and determined their tumorigenicity. K1735 transfectants expressing either Kk or Ak Ag alone produced tumors in normal C3H mice, whereas most transfectants that expressed both molecules were rejected in normal C3H mice but produced tumors in nude mice. However, the Ak Ag requirement can be substituted by IL-2 because transfection of Kk-positive/Ak-negative K1735 cells with the IL-2 gene also resulted in abrogation of tumorigenicity in normal C3H mice but not in nude mice. Similarly, transfection of Kk-negative/Ak-positive K1735 cells with IFN-gamma gene resulted in induction of MHC class I Ag as well as rejection of these tumors in normal C3H mice. The rejection of K1735 transfectants expressing Kk and Ak Ag in normal C3H mice required both CD4+ and CD8+ T cells. In addition, the transplantation immunity induced by K1735 transfectants expressing both Kk and Ak Ag completely cross-protected mice against challenge with Kk-positive transfectants but only weakly protected them against challenge with parental K1735 cells or Ak-positive transfectants. These results indicate that expression of either MHC class I or II Ag alone is insufficient to cause the rejection of K1735 melanoma in syngeneic hosts and that both Ag are necessary. In addition, our data suggest that the failure of Kk-positive K1735 cells to induce a primary tumor rejection response in normal C3H mice may result from their inability to induce the helper arm of the antitumor immune response.

Rejection of K1735 murine melanoma in syngeneic hosts requires expression of MHC class I antigens and either class II antigens or IL-2

Tumor specific immunity is mediated by CTL that recognize peptide Ag in the context of MHC class I molecules and by Th cells that recognize peptide Ag in the context of MHC class II molecules. To clarify the relative importance of MHC class I and II Ag in tumor rejection, we transfected a K1735 melanoma that did not express constitutively either MHC class I or II Ag with H-2Kk and/or I-Ak genes and determined their tumorigenicity. K1735 transfectants expressing either Kk or Ak Ag alone produced tumors in normal C3H mice, whereas most transfectants that expressed both molecules were rejected in normal C3H mice but produced tumors in nude mice. However, the Ak Ag requirement can be substituted by IL-2 because transfection of Kk-positive/Ak-negative K1735 cells with the IL-2 gene also resulted in abrogation of tumorigenicity in normal C3H mice but not in nude mice. Similarly, transfection of Kk-negative/Ak-positive K1735 cells with IFN-gamma gene resulted in induction of MHC class I Ag as well as rejection of these tumors in normal C3H mice. The rejection of K1735 transfectants expressing Kk and Ak Ag in normal C3H mice required both CD4+ and CD8+ T cells. In addition, the transplantation immunity induced by K1735 transfectants expressing both Kk and Ak Ag completely cross-protected mice against challenge with Kk-positive transfectants but only weakly protected them against challenge with parental K1735 cells or Ak-positive transfectants. These results indicate that expression of either MHC class I or II Ag alone is insufficient to cause the rejection of K1735 melanoma in syngeneic hosts and that both Ag are necessary. In addition, our data suggest that the failure of Kk-positive K1735 cells to induce a primary tumor rejection response in normal C3H mice may result from their inability to induce the helper arm of the antitumor immune response.

Intraoperative radiotherapy in retroperitoneal sarcomas. Final results of a prospective, randomized, clinical trial

Thirty-five patients with surgically resected sarcomas of the retroperitoneum were enrolled in a prospective, randomized, clinical trial comparing 20-Gy intraoperative radiotherapy in combination with postoperative low-dose (35- to 40-Gy) external-beam radiotherapy with postoperative high-dose (50- to 55-Gy) external-beam radiotherapy alone. Chemotherapy with doxorubicin hydrochloride, cyclophosphamide (anhydrous), and methotrexate sodium was used for a portion of the trial. Fifteen patients who received intraoperative radiotherapy and 20 control patients were followed up for a minimum of 5 years (median follow-up, 8 years). Median survival times were similar for the group that received intraoperative radiotherapy (45 months) and the control group (52 months). There were no indications of benefit from adjunctive chemotherapy. The number of locoregional recurrences was significantly lower among those who received intraoperative radiotherapy (six of 15) than control patients (16 of 20). Patients who received intraoperative radiotherapy had fewer complications of disabling radiation-related enteritis (two of 15) than control patients (10 of 20), but radiation-related peripheral neuropathy was more frequent among those who received intraoperative radiotherapy (nine of 15) than among control patients (one of 20).

Resistance of Ha-ras oncogene-induced progressor tumor variants to tumor necrosis factor and interferon-gamma

To elucidate the mechanisms by which tumor cells escape the immune defenses of the normal host, we have isolated progressor tumor variants from a regressor tumor cell line by transfection with an activated Ha-ras oncogene. We previously found that the progressor phenotype of Ha-ras-induced variants was not due to loss of tumor-specific or major histocompatibility complex antigens. In this study, we investigated whether there is any correlation between in vivo tumor growth and in vitro sensitivity of regressor and progressor tumor cells to tumor necrosis factor (TNF). The regressor UV-2240 tumor cells, which do not grow in normal syngeneic mice, were sensitive to killing by TNF, whereas the Ha-ras oncogene-induced progressor tumor variants of UV-2240, which produce tumors in normal syngeneic hosts, were resistant to killing by TNF. Interferon-gamma (IFN-gamma) enhanced TNF-induced cytotoxicity of the regressor tumor cells, but it had no effect on Ha-ras-induced progressor tumor variants. The resistance of the Ha-ras-induced progressor variants to TNF and IFN-gamma could be attributed to a decrease in the number of TNF receptors on their cell surface. However, there was no correlation between TNF and IFN-gamma sensitivity of tumor cells and sensitivity to killing by activated macrophages, NK or NC cells. These results indicate that in some murine tumor cells, there may be a relationship between in vivo tumor growth and in vitro resistance to cytolysis by TNF and IFN-gamma. Although the response of the Ha-ras-induced progressor variants to TNF and IFN-gamma produced endogenously in immunocompetent mice is unknown, one can infer that some tumors escape the immune defenses of the normal host by becoming resistant to certain cytokines produced by the immune system.

Immune response to somatic cell hybrids between ultraviolet radiation-induced regressor and spontaneous progressor C3H mouse tumor cells

We used somatic cell hybridization to determine whether the regressor phenotype exhibited by UV-induced murine tumors was dominant or recessive and whether this technique could confer immunogenic properties on nonimmunogenic syngeneic tumors. We transfected a highly antigenic UV-induced C3H mouse tumor cell line (UV-2240) with the plasmid pSV2-neo and selected G418-resistant clones. The resulting cell line was fused with a spontaneously transformed nonimmunogenic C3H progressor tumor cell line (SF-2T) that had been selected previously for resistance to 3.0 mM ouabain. These two cell lines were fused by a brief exposure to polyethylene glycol and heterokaryons isolated by growth in medium containing both G418 and ouabain. Hybrid cell lines established from individual colonies and from pools of colonies were tested for tumorigenicity in normal C3H and athymic nude mice. The results indicated that all the hybrid cell lines tested were highly antigenic in that they were completely rejected when transplanted into normal syngeneic mice but grew progressively in nude mice. Furthermore, immunization of C3H mice with the hybrid cell lines induced protective immunity against challenge with the immunizing tumor and generated cross-protective immunity against challenge with the regressor parental cell line but not against challenge with the progressor parental cell line. These results demonstrate that the regressor phenotype of the UV-2240 tumor is dominant in nature and that the immune response induced by somatic cell hybrids is uniquely directed against the dominant tumor-specific transplantation antigens expressed on the regressor tumor. This implies that introduction of tumor-specific transplantation antigens from an immunogenic tumor into a nonimmunogenic tumor, although sufficient to confer immunogenic properties to the hybrid, is insufficient to induce cross-protective transplantation immunity against the nonimmunogenic tumor.

Psychiatric needs in local jails: emergency issues

There is an urgent need for psychiatric services for mentally ill inmates in local jails. The authors recommend that a psychiatric team be established inside the jail to provide short-term crisis evaluation, disposition, and treatment; that special training be provided for jail booking personnel in the recognition of psychiatric problems during the initial jail screening and classification process; that special modules be developed for mentally ill inmates; and that inmates in need of hospitalization have easy access to hospital beds. They describe a psychiatric ward actually located within a county jail to treat mentally ill inmates who are considered security risks.