Reduction of FK-506 requirements by combination with polyethylene glycol superoxide dismutase in orthotopic rat liver transplantation

Reperfusion after ischemia results in endothelial cell injury and Kupffer cell activation. Inflammatory cytokines thus released can induce major histocompatibility complex antigens and increase the immunogenecity of the graft. An orthotopic rat liver allotransplant model was used to test the hypothesis that prevention of reperfusion injury by infusion of polyethylene glycol superoxide dismutase (PEG-SOD) would result in long-term allograft survival in the presence of subthreshold immunosuppressive dosages. ACI rats were used as donors, and Lewis strain rats as recipients. Orthotopic liver transplantation was initially performed to identify a subthreshold dose of the immunosuppressant FK-506, which would be unable to extend survival longer than control untreated rats with this strain combination. After testing three intramuscular FK-506 doses of 0.04, 0.08, and 0.16 mg/kg, it was observed that an FK-506 dose of 0.04 mg/kg/day for 14 days was unable to extend survival longer than in untreated recipients. This dose of FK-506 was used in combination with PEG-SOD at doses of 1000, 3000, 10,000, or 30,000 units. Recipient animals were treated intravenously with PEG-SOD as a loading dose to facilitate tissue penetration on day 1, and beginning on the day of transplantation, every 2 days for the duration of the study. Results of histologic studies and mean survival time were compared in untreated recipients and in rats treated with PEG-SOD plus 0.04 mg/kg/day FK-506. Mean survival time was increased significantly in these animals (p < 0.007) to 40.6 ± 25.6 days as compared with either untreated rats (10.0 ± 2.7 days) or rats treated with 0.04 mg/kg FK-506 alone (13.7 ± 4.2 days). Histologic examination demonstrated a significant reduction in the cellular infiltrate in rats treated with PEG-SOD plus FK-506, as compared with recipients treated with either agent alone or left untreated. Our results therefore suggest a potential approach to reducing immunosuppression in transplantation. (J ALLERGY CLIN IMMUNOL 1995;95:1276-81.)     

Establishment and characterization of αs1-casein–specific T-cell lines from patients allergic to cow’s milk: Unexpected higher frequency of CD8 T-cell lines

To study cow’s milk allergy at the cellular level, we assessed the reactivity of peripheral blood mononuclear cells from patients allergic to cow’s milk to α_s1-casein, which is one of the major allergens in cow’s milk. Proliferation of the cells to α_s1-casein activation showed a rather weak response. Therefore to understand T-cell reactivity to α_s1-casein in more detail, we prepared α_s1-casein–specific T-cell lines from patients allergic to cow’s milk and established 26 T-cell lines. These T-cell lines could be classified into three groups by analyzing their surface marker expression: those containing predominantly CD4⁺CD8^- T cells, those containing both CD4⁺CD8^- and CD4^-CD8⁺ T cells, and those containing predominantly CD4^-CD8⁺ T cells. The CD8⁺ T cells were obtained at an unexpectedly higher frequency from the patients. These T-cell lines produced interferon-γ and IL-4. These results suggest that CD8⁺ T cells specific for α_s1-casein and CD4⁺ T cells were primed by the stimulation with α_s1-casein in patients allergic to milk and that both T cells may play a key role in the onset, progression of, or recovery from cow’s milk allergy. (J ALLERGY CLIN IMMUNOL 1996;97:1342-9.)     

Novel appearance of placental nuclear monoamine oxidase: Biochemical and histochemical evidence for hyperserotonomic state in preeclampsia-eclampsia

OBJECTIVE: The aim of this study was to explore the relevance of placental monoamine oxidase at the subcellular level in the etiology of the hyperserotonomic state in preeclampsia-eclampsia. STUDY DESIGN: The study was conducted on placentas from 20 normal pregnant women and 25 women with varied severity of preeclampsia-eclampsia. Placental serotonin and subcellular monoamine oxidase activity were determined. Histochemical localization of monoamine oxidase was done in placental sections and cell isolates. RESULTS: Placental serotonin increases with severity (r_systolic 0.84, r_diastolic 0.83) and monoamine oxidase decreases (r_systolic 0.86, r_diastolic 0.79). Placental monoamine oxidase showed marked changes in preeclampsia-eclampsia. Histochemical localization of monoamine oxidase showed diffused low activity evenly throughout the cytoplasm and nucleus of the syncytiotrophoblastic cells in preeclampsia-eclampsia; in contrast, normal placenta showed high activity in the cytoplasm without any activity in the nucleus of syncytiotrophoblastic cells. Detection of monoamine oxidase activity in nuclei of the placenta in preeclampsia-eclampsia is a novel finding. Monoamine oxidase activity at the subcellular level further strengthens this observation. A severity-dependent decrease was present in the nuclei of placentas with preeclampsia-eclampsia. The use of specific substrates and inhibitors revealed the presence of monoamine oxidase in mitochondria and nucleus. CONCLUSION: The study delineates an impaired catabolism of placental serotonin in preeclampsia-eclampsia. The novel appearance of monoamine oxidase in nuclei in proximity to its normal site and low activity resulting in a hyperserotonomic state may lead to preeclampsia-eclampsia. (Am J Obstet Gynecol 1996;175:1543-50.)     

Interobserver test-retest reliability of the randot preschool stereoacuity test

PURPOSE: Random dot stereoacuity can be quantified to between 40 and 800 seconds of arc in preschool children by using the Randot Preschool Stereoacuity test (Stereo Optical Co, Inc, Chicago, Ill). To incorporate this test into clinic and research settings, the reliability of its stereoacuity scores obtained by separate examiners needs to be evaluated. The purpose of this study was to evaluate its interobserver test-retest reliability. METHODS: Participants included 102 consecutive children with binocular sensory function ranging from fine to no measurable stereopsis. Clinical research participants included children with anomalous binocular vision caused by strabismus, cataracts, anisometropia, and ptosis. In a prospective study, random dot stereoacuity was measured twice under masked testing conditions by 2 examiners within a 1-hour period. RESULTS: Interobserver test-retest reliability of the Randot Preschool Stereoacuity test is high among a population of children with diverse binocular sensory function. The correlation coefficient between individual test scores was highly significant (r = 0.97, P<.001). Mean differences between the 2 scores (0.021 log seconds of arc) were not significantly different from zero (t(99) = 1.33, P>.1). The upper and lower limits of agreement were narrow, reflecting both the large sample size and the small variation between the 2 test scores. Interobserver test-retest reliability of the Randot Preschool Stereoacuity test was nearly constant across levels of functional stereoacuity, patient categorization, and age at the time of the test. CONCLUSIONS: The high agreement between the Randot Preschool Stereoacuity test scores by 2 independent observers supports its use in clinical management and research settings for the quantitative assessment of binocular sensory vision, as well as in multicentered research studies.     

Immunochemical characterization of edible bird’s nest allergens

Background: We have previously described anaphylaxis induced by edible bird’s nest (BN) and demonstrated that this condition is IgE mediated. Objectives: This study aimed at describing the immunochemical properties of the BN allergens. Comparative studies between 3 commercially available sources (according to the country of origin) of BN were also made. Methods: Crude extracts of commercially available processed BN from Sarawak (Malaysia), Thailand, and Indonesia and fresh unprocessed BN from the caves of Sarawak were obtained by means of aqueous extraction. Specific IgE toward these sources were determined by using fluorescence allergosorbent tests (FASTs). Cross-reactivity studies between the 3 sources of commercially available processed BN were carried out by means of FAST inhibition. Immunochemical characterization by means of IgE immunoblot, periodate treatment, and heat stability studies were carried out on fresh unprocessed BN from Sarawak. Results: Serum from allergic patients showed differences in IgE binding to the 3 sources of commercially available BN, with the highest levels of specific IgE recorded with the Sarawak source (P < .0001). Of these, only the Sarawak and Thailand sources showed considerable cross-reactivity. Further work on the unprocessed fresh Sarawak source identified a putative 66-kd major allergen containing several isoforms. Periodate treatment resulted in loss of IgE binding. Despite a progressive decline in the molecular weights of allergens on SDS-PAGE with increasing periods of boiling, IgE binding, as assessed by means of FAST, was not affected. N-terminal sequence of the major putative allergen (66 kd) showed homology to a domain of an ovoinhibitor precursor in chicken (SWISS-PROT accession No. P10184). Conclusions: We have described the immunochemical properties of BN allergens. Edible BN from different sources are allergenically dissimilar. The putative major allergen is a 66-kd protein. (J Allergy Clin Immunol 2001;107:1082-8.)     

Langerhans-like dendritic cells generated from cord blood progenitors internalize pollen allergens by macropinocytosis, and part of the molecules are processed and can activate autologous naive T lymphocytes

Background: The safety and efficacy of sublingual immunotherapy have been demonstrated in moderate allergic asthma and seasonal rhinitis. However, not much is known about the precise mechanism of action of the allergen when it crosses the oral mucosa. Objective: To define this mechanism, we investigated the role of Langerhans’ cells in the capture and internalization of allergens. Methods: We generated dendritic cells in vitro with the phenotypic characteristics of Langerhans-like dendritic cells (LLDCs) from cord blood CD34⁺ progenitors. We used two recombinant major allergens: Bet v 1 and Phl p 1 labeled with FITC. Results: Internalization of allergens and control proteins was dose- and time-dependent and related to the immature state of the cells. LLDCs internalized allergens with a high efficiency in comparison with control molecules. Allergens were only internalized by macropinocytosis, as demonstrated by the use of various inhibitors. Addition of intracellular pH-modifying molecules indicated that only a part of the allergens was accumulated in acidic vesicles, whereas the majority remained in other cytoplasmic structures. Pulse-chase experiments calculated a half-life of 4 hours, suggesting that part of the molecules were not metabolized in the lysosome. Allergen internalization by LLDCs might be followed by processing in some experiments, as demonstrated by activation of autologous T lymphocytes in 4 of 9 experiments. Conclusion: These elements showed that Langerhans’ cells present in mucosa might play an active role in immune responses to allergens. (J Allergy Clin Immunol 2000;105:1194-1201.)     

Unilateral retinal hemorrhages and ipsilateral intracranial bleeds in nonaccidental trauma

The classic ophthalmologic finding in nonaccidental traumatic injury is bilateral widespread retinal hemorrhage with or without intracranial hemorrhage. We present 3 cases of unilateral retinal hemorrhage associated with ipsilateral intracranial bleeds to extend the many different presentations of nonaccidental trauma.     

Granulocytic sarcoma occurring in the maxillary gingiva demonstrated by magnetic resonance imaging

We report the case of a 43-year-old woman presenting with a painless swelling that had developed over 8 months in the maxillary labial vestibule. An oral examination revealed an exophytic, firm, black-pigmented lesion measuring 3.5 x 1.5 cm that bled on palpation. Periapical radiographs showed a slightly enlarged periodontal ligament space of the left central incisor and bone resorption in the region of the missing lateral incisor. Panoramic and other conventional radiographs showed no obvious lytic area, and a magnetic resonance imaging examination demonstrated a low signal intensity lesion on both the T1-weighted and the T2-weighted images. Therefore, granulocytic sarcoma was suspected.Granulocytic sarcoma of the oral cavity is a rare condition, and its diagnosis is usually difficult. Increased awareness of this entity may minimize misinterpretation of radiographic and clinical findings and can assist suitable treatment planning that is essential to this pathosis.     

Cephalometric variables as predictors of Class II treatment outcome

Cephalometric analysis of skeletodental features is accepted as an integral part of orthodontic diagnosis and treatment planning. This assumes that diagnostic cephalometric variables affect prognosis and thus help reduce malocclusion severity, which is the aim of orthodontic treatment. The aim of this study was to assess the predictive value of 41 commonly used cephalometric parameters with regard to pretreatment severity and treatment outcomes. Pretreatment severity was assessed by using the Peer Assessment Rating (PAR) occlusal index, an instrument that has been shown to be valid and reliable. Treatment outcomes consisted of (1) posttreatment malocclusion severity (post-PAR), (2) relative improvement (percent PAR reduction), and (3) treatment duration. Complete records, including cephalograms, of 223 treated Class II cases were analyzed by means of separate multiple linear regression models. Each of the outcome variables and the pretreatment severity served as the respective dependent variables, and the cephalometric parameters served as the independent or predictor variables. The cephalometric parameters explained 39.2% of the pretreatment severity variance, 17. 9% of posttreatment severity variance, 15.7% of relative treatment improvement variance, and 20.0% of treatment duration variance.     

Delayed-type hypersensitivity reaction to paraphenylenediamine is mediated by 2 different pathways of antigen recognition by specific αβ human T-cell clones

Background: Allergic contact dermatitis to paraphenylenediamine (PPD) is a frequent cause of morbidity and occupational disability. Objective: The aim of the study was to characterize T-cell responses to PPD and Bandrowski's base (BB), an autoxidation product of PPD, by using polyclonal and monoclonal T-lymphocyte cultures. Methods: PPD- and BB-driven proliferation of PBMCs and T-cell clones (TCCs) was assessed by means of tritiated thymidine incorporation. Surface markers were studied by means of flow cytometry, and cytokine generation was assessed with an ELISA. Results: TCCs, with one exception, were CD4⁺/CD45RO⁺, and T-cell receptors were αβ⁺. Three of 6 TCCs expressed Vβ 16. TCC stimulation was HLA-DP restricted, and TCCs secreted IL-4, IL-5, and marginal levels of IFN-γ. TCCs reacted to both PPD and BB. Presentation of BB to TCCs was dependent on viable antigen-presenting cells (APCs) pulsed for 4 hours, and fixed APCs failed to stimulate TCCs. Moreover, polyclonal responses to BB were enhanced by metabolically active enzymes, such as cytochrome P450 enzymes. BB has to be metabolized and processed. In contrast, fixation of APCs did not impair their ability to present PPD to TCC, whereas pulsing of APCs with PPD failed to stimulate TCCs. Thus PPD had to be present during the process, and polyclonal stimulation was not enhanced by cytochromes. Conclusion: These results suggest that PPD itself can be recognized by T cells through a processing-independent pathway, whereas its autoxidation product, BB, required processing and possibly metabolism to stimulate the same TCC. Our data demonstrate that 2 distinct pathways of antigen presentation to activate specific TCCs are involved in the immune response to PPD. (J Allergy Clin Immunol 2002;109:1005-11.)