Protein engineering of lipase A from Candida antarctica to improve esterification of tertiary alcohols.

Chiral tertiary alcohols are important organic compounds in science as well as in industry. However, their preparation in enantiomerically pure form is still a challenge due to their complex structure and steric hindrances compared with primary and secondary alcohols, so kinetic resolution could be an attractive approach.  Lipase A from Candida antarctica (CAL-A) has been shown to catalyze the enantioselective esterification of various tertiary alcohols with excellent enantioselectivity but low activity. Here we report a mutagenesis study by rational design to improve CAL-A activity against tertiary alcohols. Single mutants of CAL-A were selected, expressed, immobilized and screened for esterification of the tertiary alcohol 1,2,3,4-tetrahydronaphthalene-1-ol. A double mutant V278S+S429G showed a 1.5-fold higher reaction rate than that of the wild type CAL-A, while maintaining excellent enantioselectivity.

Strategies to Design Chemocatalytic Racemization of Tertiary Alcohols: State of the Art & Utilization for Dynamic Kinetic Resolution.

The synthesis of enantiomerically pure tertiary alcohols is an important issue in organic synthesis of a range of pharmaceuticals including molecules such as the anti-HIV drug Efavirenz. A conceptually elegant approach to such enantiomers is the dynamic kinetic resolution of racemic tertiary alcohols, which, however, requires efficient racemization strategies. The racemization of tertiary alcohols is particularly challenging due to various side reactions that can occur because of their high tendency for elimination reactions. In the last few years, several complementary catalytic concepts for racemization of tertiary alcohols have been developed, characterized by efficient racemization and suppression of unwanted side-reactions. Besides resins bearing sulfonic acid moieties and a combination of boronic acid and oxalic acid as heterogeneous and homogeneous Brønsted-acids, respectively, immobilized oxovanadium and piperidine turned out to be useful catalysts. The latter two catalysts, which have already been applied to different types of substrates, also have proven good compatibility with lipase, thus leading to the first two examples of chemoenzymatic dynamic kinetic resolution of tertiary alcohols. In this review, the difficulties in racemizing tertiary alcohols are specifically described, and the recently developed complementary concepts to overcome these hurdles are summarized.

Topical therapy and skin care for transplant-associated atopic dermatitis in children and adolescents.

BACKGROUND: New-onset allergic diseases, such as food allergy or atopic dermatitis, can develop after allogeneic transplantation. There are limited reports of new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation in children and adolescents, and its treatment is yet to be established. The pathogenesis may differ from typical atopic dermatitis in terms of alloimmunity including graft-versus-host disease. METHODS: We present five children and adolescents with new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation. The characteristics and clinical profiles of skin treatment after hematopoietic stem cell transplantation are summarized. RESULTS: Graft-versus-host disease prophylaxis included systemic tacrolimus for all patients. After hematopoietic stem cell transplantation, all patients achieved complete donor chimerism of the bone marrow and had acute graft-versus-host disease of the skin. After engraftment, all patients had skin lesions that met the international consensus diagnostic criteria for atopic dermatitis. None of the patients met the diagnostic criteria for chronic graft-versus-host disease. Topical therapy and skin care based on atopic dermatitis guidelines improved skin condition and atopic dermatitis severity scores in all patients. In addition, type 2 inflammatory markers improved accordingly. CONCLUSION: Topical therapy and skin care may be effective for transplant-related atopic dermatitis after hematopoietic stem cell transplantation. When extensive dermatitis is observed after hematopoietic stem cell transplantation, this treatment may avoid excessive immunosuppressive therapy if it meets the diagnostic criteria for atopic dermatitis.

[CURRENT STATUS OF SCHOOL LUNCHES RELATED TO FOOD ALLERGY AND UNMET NEEDS OF TEACHERS IN MIYAGI PREFECTURE].

BACKGROUND: The number of students with food allergies is on the increase, while the problems and burdens of school teachers and staff are not yet clear. Our study was designed to identify the unmet needs of school teachers and staff dealing with food allergy in school lunches. METHODS: A written questionnaire was sent by mail to 600 elementary and junior high schools in Miyagi Prefecture. RESULTS: Responses were received from 169 schools. The prevalence of food allergy was 5.6% and the EpiPen possession rate was 0.36%. The most common problems perceived by teachers and staff were the "increase in the number of students with food allergies" and the "diversification of causative foods". Other problems included "uncertainty of foods to be removed" and "insufficient collaboration among teachers, guardians, and doctors," which could be improved by the medical providers. In the free descriptions, many respondents complained of an excessive workload and the mental burden of never making a mistake or missing anything. CONCLUSION: Our survey revealed that while there is a public demand for safe school lunches, the teachers and staff dealing with this demand are under considerable strain. It is necessary to consider reducing the burden, and a sustainable system needs to be established.

[A SURVEY ON MEDICAL CARE FOR ALLERGIC DISEASES IN MIYAGI].

OBJECTIVE: In Miyagi, the number of allergy specialists per population is higher at Sendai city compared to the other areas (non-Sendai areas). Therefore, the healthcare delivery for allergic diseases are unevenly distributed. In the current study, we investigated differences of medical care for allergic diseases between Sendai city and non-Sendai areas. METHODS: We conducted a web-based questionnaire survey to all of hospitals and clinics in the prefecture. The questionnaire responses were analyzed and compared between the Sendai city and non-Sendai areas. RESULTS: Responses to the questionnaire were obtained from 175 hospitals and clinics, including 72 internal physicians, 34 pediatricians, 17 dermatologists, 15 otorhinolaryngologists, 12 ophthalmologists and 25 others. More clinicians in non-Sendai areas felt the difficulty in treating asthma and chronic urticaria than those in Sendai city. Fewer institutions prescribed biologics for severe allergic diseases in non-Sendai areas than in Sendai city, which might be due to the lack of knowledge on the biologic agents. On the other hand, referring patients with anaphylaxis to specialized hospitals tended to be more difficult in Sendai city compared to in non-Sendai areas. Additionally, the regional medical liaison system is needed to refer patients with severe allergic diseases to advanced medical institutions. CONCLUSION: There are unique problems about allergy care in Miyagi.

Enantiodivergent Chemoenzymatic Dynamic Kinetic Resolution: Conversion of Racemic Propargyl Alcohols into Both Enantiomers.

Natural lipases typically recognize enantiomers of alcohols based on the size differences of substituents near the carbinol moiety and selectively react with the R enantiomers of secondary alcohols. Therefore, lipase-catalyzed dynamic kinetic resolution (DKR) of racemic secondary alcohols produces only R enantiomers. We report herein a method for obtaining S enantiomers by DKR of secondary 3-(trialkylsilyl)propargyl alcohols by using a well-known R-selective Pseudomonas fluorescens lipase in combination with a racemization catalyst VMPS4, in which the silyl group reverses the size relationship of substituents near the carbinol moiety. We have already reported R-selective DKR of the corresponding propargyl alcohols without substituents on the ethynyl terminal carbon, and the presence of an easily removable silyl group has enabled us to produce both enantiomers of propargyl alcohols in high chemical yields and with high enantiomeric excess. In addition, immobilization of the lipase on Celite was found to be important for achieving a high efficiency of the DKR.

Lipase-Catalyzed Kinetic Resolution of C1-Symmetric Heterocyclic Biaryls.

The highly enantioselective lipase-catalyzed kinetic resolution (KR) of racemic C1-symmetric biaryl compounds including heterocyclic moieties, such as carbazole and dibenzofuran, has been achieved for the first time. This enzymatic esterification was accelerated by the addition of disodium carbonate while maintaining its high enantioselectivities, and was particularly effective for biaryls having N-substituted carbazole moieties. Furthermore, mesoporous silica-supported oxovanadium-catalyzed cross-dehydrogenative coupling of 3-hydroxycarbazole and 2-naphthol was followed by the lipase-catalyzed KR in one-pot to synthesize the optically active heterocyclic biaryl compounds with high optical purity.

[CLINICAL MANIFESTATIONS AND SAFETY OF AN ORAL FOOD CHALLENGE USING BOILED EGG YOLK].

BACKGROUND: Allergenicity to heated egg yolks is known to be low in hen's egg allergy. However, there are few reports concerning the safety of an oral food challenge (OFC) with boiled egg yolks. This study aimed to determine the safety of a boiled egg yolk OFC and the clinical characteristics of patients who were OFC-positive. METHODS: We retrospectively examined the data of patients who underwent an OFC with one boiled egg yolk at Miyagi Children's Hospital between January 2013 and December 2020. Patients were included if they had a history of immediate symptoms due to hen's egg or positive specific IgE levels to egg yolk or egg white. RESULTS: Among 600 patients, 15.0% were positive for OFC, only one patient required an intramuscular adrenaline injection, and 70% of OFC-positive patients had gastrointestinal symptoms. CONCLUSION: Boiled egg yolk OFC had a low symptom induction rate; however, when symptoms were induced, gastrointestinal symptoms were most commonly observed. Given the low risk of developing severe symptoms, we conclude that the likelihood of safely performing an OFC is high.

Use of a home-visit nursing service to manage severe atopic dermatitis in a child with difficult family environment.

Maintenance therapy of atopic dermatitis (AD) with frequent exacerbations needs proactive use of topical corticosteroids or topical calcineurin inhibitors. However, it can be difficult for children in an unfavorable family environment. Home-visit nursing service (HVNS) plays an important role in delivering care to people who need medical help at home. We report a boy in a difficult family situation who received HVNS to successfully manage AD.

[CHARACTERISTICS OF THE SYMPTOMS DURING FOOD AND EXERCISE PROVOCATION TESTS IN PATIENTS AFTER ORAL IMMUNOTHERAPY: COMPARISON WITH FOOD-DEPENDENT EXERCISE-INDUCED ANAPHYLAXIS].

OBJECTIVE: We aim to examine the characteristics of the symptoms induced by exercise provocation tests following allergen consumption in patients who have undergone oral immunotherapy (OIT). METHOD: Patients who were positive for exercise provocation tests in Miyagi Children's Hospital from April 2012 to January 2019 were retrospectively analyzed. Patients were classified into food-dependent exerciseinduced anaphylaxis (FDEIA) group and post-OIT-FDEIA group. RESULT: Six patients in the FDEIA group and 19 patients in the post-OIT-FDEIA group were analyzed. There were no significant differences in age, sex, and number of complications between the FDEIA and post-OIT-FDEIA groups, except for level of total serum immunoglobulin E. The median time from the start of exercise to onset of symptoms was 20 min in the FDEIA group and 25 min in the post-OIT-FDEIA group. The rate of adrenaline administration in post-OIT-FDEIA group was significantly lower. The median time from exercise to onset of severe symptoms requiring adrenaline was 32.5 min in the FDEIA group and 25 min in the post-OIT-FDEIA group. CONCLUSION: These data suggest that FDEIA and post-OIT-FDEIA patients can exhibit similar clinical symptoms, and all symptoms occurred in 60 minutes after exercise.

[SAFETY OF A THREE-LEVEL STEPWISE ORAL FOOD CHALLENGE FOR PEANUT ALLERGY].

BACKGROUND: The present study aimed to assess the safety of a three-level stepwise oral food challenge (OFC) in patients with peanut allergy. METHODS: This retrospective analysis reviewed laboratory test results and food allergy histories (obtained from medical records) of participants who underwent OFC using peanut butter for the first time at Miyagi Children's Hospital between January 2015 and December 2017. Total food dose was classified as follows: step 1, 0.1 g peanut butter; step 2, 0.5g peanut butter; and step 3, 3g peanut butter. RESULTS: A total of 114 participants were included. OFC-positive rates were 52% (step 1), 35% (step 2), and 20% (step 3). Of the 41 OFC-positive participants, 1 required an intramuscular adrenaline injection during step 3. Peanut allergy history rates and peanut- and Ara h 2-specific immunoglobulin E (sIgE) titers were significantly higher during the low-dose step. CONCLUSION: The three-level stepwise OFC with peanut butter is safe for patients with peanut allergy, as indicated by peanut- and Ara h 2-sIgE titers.

[PROVOCATION TESTS OF FOOD AND EXERCISE AFTER ORAL IMMUNOTHERAPY].

BACKGROUND: Oral immunotherapy (OIT) for food allergy requires exercise restrictions following the regular consumption of allergens to prevent immediate symptoms. We investigated the efficacy and the safety of exercise provocation tests to assess exercise tolerance after consumption of allergens following OIT. METHODS: This study was based on data from patients who underwent exercise provocation tests with consumption of their allergen after OIT in Miyagi Children's Hospital between April 2012 and March 2019. The results of exercise provocation tests and patients' characteristics were retrospectively analyzed. RESULTS: Fifteen out of 91 patients were positive for exercise provocation tests. The positive rates were 12% (4/33) with egg, 15% (5/34) with cow's milk, and 25% (6/24) with wheat. Intramuscular adrenaline injections were administered to two patients with allergies to egg, one with cow's milk, and one with wheat. CONCLUSION: Following OIT, the assessment using exercise provocation tests should be performed prior to termination of exercise restriction because some patients remain intolerant to exercise.

Y chromosome-linked B and NK cell deficiency in mice.

There are no primary immunodeficiency diseases linked to the Y chromosome, because the Y chromosome does not contain any vital genes. We have established a novel mouse strain in which all males lack B and NK cells and have Peyer's patch defects. By 10 wk of age, 100% of the males had evident immunodeficiencies. Mating these immunodeficient males with wild-type females on two different genetic backgrounds for several generations demonstrated that the immunodeficiency is linked to the Y chromosome and is inherited in a Mendelian fashion. Although multicolor fluorescence in situ hybridization analysis showed that the Y chromosome in the mutant male mice was one third shorter than that in wild-type males, exome sequencing did not identify any significant gene mutations. The precise molecular mechanisms are still unknown. Bone marrow chimeric analyses demonstrated that an intrinsic abnormality in bone marrow hematopoietic cells causes the B and NK cell defects. Interestingly, fetal liver cells transplanted from the mutant male mice reconstituted B and NK cells in lymphocyte-deficient Il2rg(-/-) recipient mice, whereas adult bone marrow transplants did not. Transducing the EBF gene, a master transcription factor for B cell development, into mutant hematopoietic progenitor cells rescued B cell but not NK cell development both in vitro and in vivo. These Y chromosome-linked immunodeficient mice, which have preferential B and NK cell defects, may be a useful model of lymphocyte development.

Selective expansion of donor-derived regulatory T cells after allogeneic bone marrow transplantation in a patient with IPEX syndrome.

IPEX syndrome is a rare and fatal disorder caused by absence of regulatory T cells (Tregs) due to congenital mutations in the Forkhead box protein 3 gene. Here, we report a patient with IPEX syndrome treated with RIC followed by allogeneic BMT from an HLA-matched sibling donor. We could achieve engraftment and regimen-related toxicity was well tolerated. Although the patient was in mixed chimera and the ratio of donor cells in whole peripheral blood remained relatively low, selective and sustained expansion of Tregs determined as CD4+CD25+Foxp3+ cells was observed. Improvement in clinical symptoms was correlated with expansion of donor-derived Tregs and disappearance of anti-villin autoantibody, which was involved in the pathogenesis of gastrointestinal symptoms in IPEX syndrome. This clinical observation suggests that donor-derived Tregs have selective growth advantage in patients with IPEX syndrome even in mixed chimera after allogeneic BMT and contribute to the control of clinical symptoms caused by the defect of Tregs.

A case series of CAEBV of children and young adults treated with reduced-intensity conditioning and allogeneic bone marrow transplantation: a single-center study.

BACKGROUND: Epstein-Barr virus (EBV)-infected T or NK cells cause chronic active EBV infection (CAEBV). Allogeneic hematopoietic stem cell transplantation (HSCT) is curative treatment for CAEBV patients. However, chemotherapy prior to HSCT and optimal conditioning regimen for allogeneic HSCT are still controversial. PATIENTS AND METHODS: We retrospectively analyzed five patients with CAEBV treated with reduced-intensity conditioning (RIC) consisted of fludarabine, cyclophosphamide, and low-dose total-body irradiation followed by allogeneic bone marrow transplantation in a single institute. Only one of five patients received chemotherapy prior to transplantation. We analyzed EBV-infected cells in a patient whose EBV load increased after HSCT by T-cell repertoire assay, separation of T-cell subpopulations, in situ hybridization and microsatellite analysis. RESULTS: All five patients achieved engraftment, complete chimera, and eradication of EBV load. All patients have been alive without any serious regimen-related toxicity for more than 16 months following HSCT. However, one patient transplanted from HLA-matched sibling donor developed clonal proliferation of CD4+ Vß3+ T cells caused by monoclonal EBV infection on day 99 after transplantation. Further analysis revealed that the CD4+ Vß3+ T cells selectively harbored EBV genome, and these infected cells were derived from donor T cells. CONCLUSIONS: Allogeneic HSCT with RIC is a safe and effective treatment for better overall survival and less regimen-related toxicity in patients with CAEBV. Our first pediatric case reported in the literature suggests that we should consider the possibility of persistent EBV infection in donor T cells as well as the relapse in recipient cells if EBV load increases after allogeneic HSCT.

Successful cord blood transplantation with reduced-intensity conditioning for childhood cerebral X-linked adrenoleukodystrophy at advanced and early stages.

Childhood cerebral ALD is a rapidly progressive and neurodegenerative disorder for which HSCT is the curative therapy if carried out at early stages. We successfully treated two patients of childhood cerebral ALD by CBT with RIC. The proband was a seven-yr-old boy whose brain MRI severity score (Loes score) was 14.5. Unrelated CBT was performed in five wk. To minimize conditioning regimen-related neurotoxicity, the combination of fludarabine (125 mg/m(2)), melphalan (140 mg/m(2)), and 4 Gy of brain-sparing TBI was used. The second patient was a six-yr-old brother of the proband. Four wk after the detection of a single small lesion (Loes score 1), he received unrelated CBT with the same RIC as the proband. In both patients, the engraftment was fast and stable, and severe complications were not observed. Furthermore, gadolinium-enhanced inflammation on brain MRI rapidly disappeared after CBT. Now, 20 and 13 months have passed after CBT, respectively, and both patients are neurologically stable. The RIC we used was sufficient for stable engraftment of cord blood and also tolerable even to the patient with advanced ALD. RIC-CBT should be considered for the patients with cerebral ALD at advanced stages, as well as those at early stages.