The Japanese Epidemiologic Study for Perioperative Anaphylaxis, a prospective nationwide study: allergen exposure, epidemiology, and diagnosis of anaphylaxis during general anaesthesia.

BACKGROUND: Diagnosis of perioperative anaphylaxis is often challenging. This study describes the utility of a newly developed tool for identifying patients with a high possibility of anaphylaxis, and aimed to investigate the frequency of anaphylaxis with each drug during the perioperative period in Japan. METHODS: This study included patients with anaphylaxis of Grade 2 or higher severity during general anaesthesia at 42 facilities across Japan in 2019 and 2020. We developed and adopted a unique objective evaluation tool yielding a composite score for diagnosing anaphylaxis, which includes the results of skin tests and basophil activation tests, and clinical scores for perioperative anaphylaxis. The number of cases using each drug and the total number of anaphylaxis cases were investigated to calculate the frequency of anaphylaxis. RESULTS: General anaesthesia was performed in 218 936 cases, which included 55 patients with suspected perioperative anaphylaxis. The developed composite score diagnosed 43 of them with a high probability of anaphylaxis. The causative agent was identified in 32 cases. Plasma histamine levels showed high diagnostic accuracy for anaphylaxis. The top causative agents were rocuronium (10 cases in 210 852 patients, 0.005%), sugammadex (7 cases in 150 629 patients, 0.005%), and cefazolin (7 cases in 106 005 patients, 0.007%). CONCLUSIONS: We developed a composite tool to diagnose anaphylaxis, and found that the combination of tryptase levels, skin testing, and basophil activation testing results and clinical score improved the certainty of anaphylaxis diagnosis. The incidence of perioperative anaphylaxis in our study was 1 in about 5000 general anaesthesia cases. CLINICAL TRIAL REGISTRATION: UMIN000035350.

Liquid Enteral Nutrients Alter the Pharmacokinetics of Orally Administered Carbamazepine in Rats.

The interaction between enteral nutrients (ENs) and drugs co-administered through a nasogastric (NG) tube reportedly affects the absorption and resultant plasma concentrations of the respective drugs. However, the gastrointestinal absorption of carbamazepine (CBZ), an antiepileptic drug, co-administered with liquid ENs through an NG tube has not been clarified. In this study, we measured the recovery rate (%) of CBZ (Tegretol® powder) passed through an NG tube when co-administered with distilled water or ENs (F2α®, Racol® NF, Ensure Liquid®, and Renalen® LP) of different compositions, frequently used in Japan. We also measured the plasma CBZ level in 26 rats after oral co-administration of CBZ with liquid ENs. The CBZ recovery rate was close to 100% in rats of all EN groups after passage through the NG tube. Furthermore, CBZ area under the plasma concentration-time curve from time zero to 9 h (AUC0→9h) of the Ensure liquid® group decreased compared with that of control group (P < 0.05) and Renalen® LP group (P < 0.01). However, the AUC0→9h of CBZ remained unchanged when co-administered with Ensure liquid® 2 h after initial CBZ administration. In conclusion, the co-administration of CBZ with Ensure Liquid® caused a reduction in the absorption of CBZ from the gastrointestinal tract, without adsorption on the NG tube. The administration of Ensure Liquid® 2 h after CBZ is a way to prevent a decrease in plasma CBZ concentration. Our findings suggest that carefully monitoring the plasma levels of CBZ is necessary in co-administation with Ensure liquid® to prevent the unintended effects of the interaction between CBZ and liquid EN.

Transcriptome analysis of Pará rubber tree (H. brasiliensis) seedlings under ethylene stimulation.

BACKGROUND: Natural rubber (cis-1,4-polyioprene, NR) is an indispensable industrial raw material obtained from the Pará rubber tree (H. brasiliensis). Natural rubber cannot be replaced by synthetic rubber compounds because of the superior resilience, elasticity, abrasion resistance, efficient heat dispersion, and impact resistance of NR. In NR production, latex is harvested by periodical tapping of the trunk bark. Ethylene enhances and prolongs latex flow and latex regeneration. Ethephon, which is an ethylene-releasing compound, applied to the trunk before tapping usually results in a 1.5- to 2-fold increase in latex yield. However, intense mechanical damage to bark tissues by excessive tapping and/or over-stimulation with ethephon induces severe oxidative stress in laticifer cells, which often causes tapping panel dryness (TPD) syndrome. To enhance NR production without causing TPD, an improved understanding of the molecular mechanism of the ethylene response in the Pará rubber tree is required. Therefore, we investigated gene expression in response to ethephon treatment using Pará rubber tree seedlings as a model system. RESULTS: After ethephon treatment, 3270 genes showed significant differences in expression compared with the mock treatment. Genes associated with carotenoids, flavonoids, and abscisic acid biosynthesis were significantly upregulated by ethephon treatment, which might contribute to an increase in latex flow. Genes associated with secondary cell wall formation were downregulated, which might be because of the reduced sugar supply. Given that sucrose is an important molecule for NR production, a trade-off may arise between NR production and cell wall formation for plant growth and for wound healing at the tapping panel. CONCLUSIONS: Dynamic changes in gene expression occur specifically in response to ethephon treatment. Certain genes identified may potentially contribute to latex production or TPD suppression. These data provide valuable information to understand the mechanism of ethylene stimulation, and will contribute to improved management practices and/or molecular breeding to attain higher yields of latex from Pará rubber trees.

Deletion of B-cell translocation gene 2 (BTG2) alters the responses of glial cells in white matter to chronic cerebral hypoperfusion.

BACKGROUND: Subcortical ischemic vascular dementia, one of the major subtypes of vascular dementia, is characterized by lacunar infarcts and white matter lesions caused by chronic cerebral hypoperfusion. In this study, we used a mouse model of bilateral common carotid artery stenosis (BCAS) to investigate the role of B-cell translocation gene 2 (BTG2), an antiproliferation gene, in the white matter glial response to chronic cerebral hypoperfusion. METHODS: Btg2-/- mice and littermate wild-type control mice underwent BCAS or sham operation. Behavior phenotypes were assessed by open-field test and Morris water maze test. Brain tissues were analyzed for the degree of white matter lesions and glial changes. To further confirm the effects of Btg2 deletion on proliferation of glial cells in vitro, BrdU incorporation was investigated in mixed glial cells derived from wild-type and Btg2-/- mice. RESULTS: Relative to wild-type mice with or without BCAS, BCAS-treated Btg2-/- mice exhibited elevated spontaneous locomotor activity and poorer spatial learning ability. Although the severities of white matter lesions did not significantly differ between wild-type and Btg2-/- mice after BCAS, the immunoreactivities of GFAP, a marker of astrocytes, and Mac2, a marker of activated microglia and macrophages, in the white matter of the optic tract were higher in BCAS-treated Btg2-/- mice than in BCAS-treated wild-type mice. The expression level of Gfap was also significantly elevated in BCAS-treated Btg2-/- mice. In vitro analysis showed that BrdU incorporation in mixed glial cells in response to inflammatory stimulation associated with cerebral hypoperfusion was higher in Btg2-/- mice than in wild-type mice. CONCLUSION: BTG2 negatively regulates glial cell proliferation in response to cerebral hypoperfusion, resulting in behavioral changes.

Increased levels of Aß42 decrease the lifespan of ob/ob mice with dysregulation of microglia and astrocytes.

Clinical studies have indicated that obesity and diabetes are associated with Alzheimer's disease (AD) and neurodegeneration. Although the mechanisms underlying these associations remain elusive, the bidirectional interactions between obesity/diabetes and Alzheimer's disease (AD) may be involved in them. Both obesity/diabetes and AD significantly reduce life expectancy. We generated AppNL-F/wt knock-in; ob/ob mice by crossing AppNL-F/wt knock-in mice and ob/ob mice to investigate whether amyloid-ß (Aß) affects the lifespan of ob/ob mice. AppNL-F/wt knock-in; ob/ob mice displayed the shortest lifespan compared to wild-type mice, AppNL-F/wt knock-in mice, and ob/ob mice. Notably, the Aß42 levels were increased at minimum levels before deposition in AppNL-F/wt knock-in mice and AppNL-F/wt knock-in; ob/ob mice at 18 months of age. No differences in the levels of several neuronal markers were observed between mice at this age. However, we observed increased levels of glial fibrillary acidic protein (GFAP), an astrocyte marker, in AppNL-F/wt knock-in; ob/ob mice, while the levels of several microglial markers, including CD11b, TREM2, and DAP12, were decreased in both ob/ob mice and AppNL-F/wt knock-in; ob/ob mice. The increase in GFAP levels was not observed in young AppNL-F/wt knock-in; ob/ob mice. Thus, the increased Aß42 levels may decrease the lifespan of ob/ob mice, which is associated with the dysregulation of microglia and astrocytes in an age-dependent manner. Based on these findings, the imbalance in these neuroinflammatory cells may provide a clue to the mechanisms by which the interaction between obesity/diabetes and early AD reduces life expectancy.

Prognosis of Incomplete Avulsion of the Proximal Hamstring Tendon Is Determined by the Avulsion Location of the Proximal Hamstring Tendon Footprint.

OBJECTIVE: To test the hypothesis that prognosis of incomplete avulsion of the proximal hamstring tendon would be worse whether avulsion location reached the proximal part of the conjoined tendon (CJ) footprint or not. DESIGN: Retrospective chart review. SETTING: Outpatient specialty clinic. PATIENTS: We reviewed 345 consecutive athletes with hamstring injury. INTERVENTIONS: Based on magnetic resonance imaging, incomplete avulsion of the proximal hamstring tendon was divided into 2 cases according to avulsion location without (cases A) or with (cases B) avulsion of the proximal part of the CJ footprint. OUTCOME MEASURES: We compared the time until return to play, subjective outcomes, and success rate of avoiding surgery between cases. RESULTS: Incomplete avulsion of the proximal hamstring tendon was detected in 47 athletes (13.6%). Thirty-four athletes were classified as cases A, and 13 as cases B. Forty-two athletes (89.4%) were followed up until return to play. The median time from pain onset to return to play was significantly longer in cases B than in cases A (B, 39.3 weeks; A, 8.0 weeks; P = 0.00015). Subjective outcomes at return to play were significantly poorer in cases B than in cases A (P = 0.00054). Success rate of avoiding surgery were significantly poorer in cases B (55%) than in cases A (100%) (P = 0.00062). CONCLUSIONS: Incomplete avulsion of the proximal hamstring tendon was observed in 13.6% of hamstring injuries. Return to play, subjective outcomes, and success rate of avoiding surgery were significantly poorer with avulsion of the proximal part of the CJ footprint.

Observational study to determine the optimal dose of daptomycin based on pharmacokinetic/pharmacodynamic analysis.

High doses of daptomycin (DAP) (>6 mg/kg/day) have been preliminarily recommended in recent practical guidelines for methicillin-resistant Staphylococcus aureus infection, to achieve better clinical effects. While such doses can elevate the plasma trough concentration (Cmin) of DAP, there is an associated risk of creatine phosphokinase (CPK) elevation warranting further investigation. In the current study relationships between DAP Cmin and CPK elevation were investigated, and optimal DAP doses were determined. Plasma DAP concentrations were measured in 20 patients. Logistic regression analysis was performed to assess relationships between DAP Cmin and CPK elevation, then a population pharmacokinetic model of DAP was developed. To determine an optimal DAP dose a Monte Carlo simulation (MCS) was performed to minimize the risk of CPK elevation and maximize the probability of successful treatment. In logistic regression analysis DAP Cmin was significantly associated with CPK elevation (odds ratio 1.21, p = 0.048). With respect to dose-dependent increases in the probability of CPK elevation and exposure to DAP, MCS estimated an optimal DAP dose of 4-6 mg/kg/day, corresponding to a minimum inhibitory concentration (MIC) of ≤0.5 µg/mL. For an MIC of 1 µg/mL, MCS estimated an optimal DAP dose of 10 mg/kg/day. However, the probability of CPK elevation associated with high doses of DAP was higher than that associated with the approved doses. In cases where high doses of DAP are administered, close CPK monitoring is required and therapeutic drug monitoring of DAP may be desirable.

Saline Solution Irrigation of the Bile Duct after Stone Removal Reduces the Recurrence of Common Bile Duct Stones.

Common bile duct (CBD) stone is a relatively common but potentially life-threatening disease. Endoscopic sphincterotomy (EST) has been performed as standard therapy for CBD stones, but the rate of recurrence of CBD stones is high. Risk factors have been poorly defined, and no effective means for the prevention of the recurrence of CBD stones have been established so far. We aimed to identify significant risk factors for the recurrence of bile duct stones. This study included 477 patients (231 women; mean age, 80.5 years) who underwent EST and cleared CBD stones on cholangiography. A retrospective analysis was performed for the consecutively collected data. During the follow-up period of 6-75 months, the recurrence of CBD stones was observed in 99 patients (20.8%). The median time to the recurrence was 19.0 months (range 4-72 months). Multivariate analysis identified the need for mechanical lithotripsy, which was used for stone fragmentation, as a risk factor. Mechanical lithotripsy caused cholangiography-negative small residua. Notably, saline solution irrigation of the bile duct reduced the recurrence of CBD stones. These results demonstrate that subsequent biliary irrigation after stone removal may prevent the recurrence of CBD stones by clearing small residual fragments.

Clinical and molecular genetic characterization of two siblings with trisomy 2p24.3-pter and monosomy 5p14.3-pter.

Partial trisomy 2p syndrome is occasionally associated with neural tube defects (NTDs), such as anencephaly, encephalocele, and spina bifida, in addition to common features of intellectual disability, developmental delay, and characteristic facial appearance. The 2p24 region has been reported to be associated with NTDs. Here, we report the cases of 2 siblings with trisomy 2p24.3-pter and monosomy 5p14.3-pter caused by the paternal translocation t(2;5)(p24.3;p14.3). Of the two siblings, the elder sister had spina bifida. We determined the nucleotide sequences of the chromosomal breakpoints and found that the sizes of trisomy 2p and monosomy 5p segments were 18.77 and 17.89 Mb, respectively. NTDs were present in four of seven previously reported patients with trisomy 2p and monosomy 5p as well as in one of the two patients examined in the present study. Although the monosomy 5p of the nine patients were similar in size, the two patients reported here had the smallest size of trisomy 2p. When the clinical features of the nine patients were compared to the present two patients, the elder sister had postaxial polydactyly of the left foot in addition to the characteristic facial appearance and spina bifida, indicating that these features were associated with trisomy 2p24.3-pter. To our knowledge, this is the first study on spina bifida to determine the nucleotide sequences of breakpoints for trisomy 2p24.3-pter and monosomy 5p14.3-pter. Increased gene dosages of dosage-sensitive genes or genes at the trisomy segment (2p24.3) of the presented patients could be associated with NTDs of patients with trisomy 2p.

A bHLH-type transcription factor, ABA-INDUCIBLE BHLH-TYPE TRANSCRIPTION FACTOR/JA-ASSOCIATED MYC2-LIKE1, acts as a repressor to negatively regulate jasmonate signaling in arabidopsis.

Jasmonates (JAs) are plant hormones that regulate the balance between plant growth and responses to biotic and abiotic stresses. Although recent studies have uncovered the mechanisms for JA-induced responses in Arabidopsis thaliana, the mechanisms by which plants attenuate the JA-induced responses remain elusive. Here, we report that a basic helix-loop-helix-type transcription factor, ABA-INDUCIBLE BHLH-TYPE TRANSCRIPTION FACTOR/JA-ASSOCIATED MYC2-LIKE1 (JAM1), acts as a transcriptional repressor and negatively regulates JA signaling. Gain-of-function transgenic plants expressing the chimeric repressor for JAM1 exhibited substantial reduction of JA responses, including JA-induced inhibition of root growth, accumulation of anthocyanin, and male fertility. These plants were also compromised in resistance to attack by the insect herbivore Spodoptera exigua. Conversely, jam1 loss-of-function mutants showed enhanced JA responsiveness, including increased resistance to insect attack. JAM1 and MYC2 competitively bind to the target sequence of MYC2, which likely provides the mechanism for negative regulation of JA signaling and suppression of MYC2 functions by JAM1. These results indicate that JAM1 negatively regulates JA signaling, thereby playing a pivotal role in fine-tuning of JA-mediated stress responses and plant growth.

Analysis of cysteine and histidine residues required for zinc response of the transcription factor human MTF-1.

Metal responsive element (MRE)-binding transcription factor-1 (MTF-1) is a zinc finger (ZF) transcription factor that plays a key role in heavy metal homeostasis by regulating relevant genes in response to metals. MTF-1 is known to be activated by heavy metals such as Zn and Cd, but the mechanism of activation remains unclear. In the present study, Cys and His residues of human MTF-1 (hMTF-1), some of which may be involved in interaction with metals or with each other, were screened for their contribution to Zn-dependent transcription. To avoid poor induction ratios of previous transfection assays, we re-examined experimental conditions to establish an assay able to correctly detect Zn-responsive transcription. Using this assay, a series of Cys and/or His substitution mutants were analyzed over the entire hMTF-1 molecule. In five out of the six ZFs (ZF1 to ZF5), Cys mutations that disrupt the ZF structure abolished response to Zn. Of these, ZF5 was shown for the first time to be essential for Zn-responsive transcription, despite it being unnecessary for Zn-induced DNA binding. These results indicate that Zn activation of hMTF-1 involves an additional process besides induction of DNA binding activity. Our assay also confirmed the importance of Cys in the acidic activation domain, as well as those in the C-terminal Cys cluster, implicated in transcription in other studies. The identified Cys residues might contribute to metal response of hMTF-1 through direct metal binding and/or intramolecular interactions, analysis of which will be helpful in understanding the mechanism of metal response.

Structures of DNA duplexes containing O6-carboxymethylguanine, a lesion associated with gastrointestinal cancer, reveal a mechanism for inducing pyrimidine transition mutations.

N-nitrosation of glycine and its derivatives generates potent alkylating agents that can lead to the formation of O(6)-carboxymethylguanine (O(6)-CMG) in DNA. O(6)-CMG has been identified in DNA derived from human colon tissue, and its occurrence has been linked to diets high in red and processed meats. By analogy to O(6)-methylguanine, O(6)-CMG is expected to be highly mutagenic, inducing G to A mutations during DNA replication that can increase the risk of gastrointestinal and other cancers. Two crystal structures of DNA dodecamers d(CGCG[O(6)-CMG]ATTCGCG) and d(CGC[O(6)-CMG]AATTCGCG) in complex with Hoechst33258 reveal that each can form a self-complementary duplex to retain the B-form conformation. Electron density maps clearly show that O(6)-CMG forms a Watson-Crick-type pair with thymine similar to the canonical A:T pair, and it forms a reversed wobble pair with cytosine. In situ structural modeling suggests that a DNA polymerase can accept the Watson-Crick-type pair of O(6)-CMG with thymine, but might also accept the reversed wobble pair of O(6)-CMG with cytosine. Thus, O(6)-CMG would permit the mis-incorporation of dTTP during DNA replication. Alternatively, the triphosphate that would be formed by carboxymethylation of the nucleotide triphosphate pool d[O(6)-CMG]TP might compete with dATP incorporation opposite thymine in a DNA template.

[Examination of Measures for Preventing Exposure in Nurses Who Handle Cyclophosphamide].

Health hazards due to long-term exposure to anticancer drugs have been reported among health care professionals. In Yamagata Prefectural Central Hospital, constant use of personal protective equipment(gloves and mask with face shield)is mandatory, but there is no clear description of the protective gown. To verify the exposure status of nurses while handling cyclophosphamide and the usefulness of a protective gown as a protective measure, urinary concentration of cyclophosphamide was measured for nurses who handled cyclophosphamide. No cyclophosphamide was detected in the urine samples collected from nurses who handled cyclophosphamide while wearing protective gowns or in the samples collected from nurses who handled cyclophosphamide without protective gowns. This finding suggests that gloves and a mask with a face shield are sufficient for preventing exposure to cyclophosphamide. However, considering that only experienced nurses were included as subjects in this study, we cannot conclude that a protective gown is unnecessary, because inexperienced nurses may be exposed to cyclophosphamide. Our study's findings may be one reference to examine measures for preventing exposure in nurses.

The characteristic structure of anti-HIV actinohivin in complex with three HMTG D1 chains of HIV-gp120.

The anti-HIV lectin actinohivin (AH) specifically interacts with HMTG (high-mannose-type glycan), which is attached to the glycoprotein gp120 of HIV-1 in a process in which the three branched mannotriose chains (D1, D2, and D3) of HMTG exhibit different binding affinities, it being estimated that that of D1 is the strongest, that of D3 is weaker, and that of D2 is undetectable. These properties have been ascribed to the stereochemical differences in linkages between the second and the third mannose residues of the three chains. In order to clarify the interaction geometry between AH and the major target D1, an X-ray determination of the crystal structure of AH in complex with D1-which is α(1,2)mannotriose composed of three mannose (Man) residues linked together only by α(1,2) bonding-has been performed. In each of the three D1-binding pockets of AH, two Man residues of D1 are accommodated at zones 1 and 2 in the pocket, in the same way as those found in the α(1,2)mannobiose-bound AH crystals. However, an OMIT map shows poor densities at both ends of the two residues. This suggests the existence of positional disorder of D1 in the pocket: the two zones are each occupied by two Man residues in two different modes, with mode A involving the Man1 and Man2 residues and mode B the Man2 and Man3 residues. In each mode, D1 is stabilized by adopting a double-bracket-shaped conformation through CH⋅⋅⋅O interactions. In mode B, however, the Man1 residue, which is the most sensitive residue to AH binding, protrudes wholly into the solvent region without contacts with AH. In mode A, in contrast, the Man3 residue interacts with the essential hydrophobic amino acid residues (Tyr and Leu conserved between the three pockets) of AH. Therefore, mode A is likely to be the one that occurs when whole HMTG is bound. In this mode, the two hydroxy groups (O3 and O4) of the Man2 residue are anchored in zone 2 by four hydrogen bonds with Asp, Asn, and Tyr residues of AH. In addition, it has been found that an isolated water molecule buried in the hydrophobic long loop bridges between Asp of AH and the hydroxy group of Man2 through hydrogen bonds. The most interesting feature is found in the interaction of the Man1 and Man3 residues with AH. All eight hydroxy groups of the two residues are completely exposed in the solvent region, whereas their hydrophobic parts make contacts with a Leu residue and two Tyr residues so that the shape of D1 and the surface of AH fit well over a wide area. These structural characteristics are potentially useful for development of AH to produce more effective antiretroviral drugs to suppress the infectious expansion of HIV/AIDS and to help expedite an end to the HIV/AIDS pandemic in the near future.

Chimeric repressor analysis identifies MYB87 as a possible regulator of morphogenesis via cell wall organization and remodeling in Arabidopsis.

Plant growth and development require proper cell wall organization but little is known about the transcription factors responsible for the regulation of gene expression involved in cell wall organization. Here we show, using Arabidopsis thaliana, that constitutive expression of the chimeric repressor for the MYB87 transcription factor causes suppression of longitudinal elongation, aberrant radial growth, and radially expanded or swollen cells in multiple organs. Microarray analysis revealed that plants expressing the chimeric repressor have altered expression of various cell wall related genes. MYB87 may therefore function as a regulator of genes affecting cell wall organization and remodeling. These findings improve our understanding of cell wall regulation and its roles in plant growth and development and also contribute information that may allow engineering of plant growth and architecture.

[Decision making support for chemotherapy outpatients and their families: role of the home care professional].

The intervention of palliative care from the early stages of cancer is advocated, however, current situation remains virtually unchanged. Since the Baptist Home Hospice Palliative Care Clinic opened, the percentage of patients who have been introduced to the clinic during chemotherapy and have received home-visit care is 16.1%. Of those, the percentage of patients who passed away more than two months since the start of home-visit care is 45.7%. We determine the direction in care by listening closely to our patients and their families, and putting advance care planning (ACP) into effect. One of our roles is to offer support in deciding to discontinue the treatment in the final stages of chemotherapy. It is recognized that a number of patients are undergoing ineffective chemotherapy, despite the strong side effects. Our clinic strives to help these patients spend time the way they want by providing home-visit care and home-visit nursing.

[Palliative care for patients with hematological malignancies in the Japan Baptist Medical Foundation].

The Japan Baptist Medical Foundation has established a "hospice triangle" system consisting of the hospice ward, general ward, and home hospice. Palliative care is provided for patients with various types of cancer, including hematological malignancies, in the place where they desire to receive care. From December 2010 to December 2013, 37 patients with hematological malignancies received palliative care and died at our foundation. Eleven (30%) patients died in the hospice ward, 24 (65%) in the general ward, and 2 (5%) at home. The median interval between the final dose of chemotherapy and death was 12 (1- 88) days. Twenty (54%) patients received transfusions during the last 2 weeks prior to death. Quick response to patient situations and early introduction of palliative care are essential to support end-of-life decision-making processes, because the clinical course of hematological malignancies generally differs from that of other cancers.

Peculiarity in crystal packing of anti-HIV lectin actinohivin in complex with α(1-2)mannobiose.

Previously, the anti-HIV lectin actinohivin (AH) was cocrystallized with the target α(1-2)mannobiose (MB) in the apparent space group P213. However, three MB-bound AH rotamers generated by ±120° rotations around the molecular pseudo-threefold rotation axis are packed randomly in the unit cell according to P212121 symmetry [Hoque et al. (2012). Acta Cryst. D68, 1671-1679]. It was found that the AH used for crystallization contains short peptides attached to the N-terminus [Suzuki et al. (2012). Acta Cryst. F68, 1060-1063], which cause packing disorder. In the present study, the fully mature homogeneous AH has been cocrystallized with MB into two new crystal forms at different pH. X-ray analyses of the two forms reveal that they have peculiar character in that the space groups are the same, P22121, and the unit-cell parameters are almost the same with the exception of the length of the a axis, which is doubled in one form. The use of homogeneous AH resulted in the absence of disorder in both crystals and an improvement in the resolution, thereby establishing the basis for AH binding to the target MB. In addition, the two crystal structures clarify the interaction modes between AH molecules, which is important knowledge for understanding the multiple binding effect generated when two AH molecules are linked together with a short peptide [Takahashi et al. (2011). J. Antibiot. 64, 551-557].