The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose-catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16 ℃ in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni-NTA affinity column.Size-exclusion chromatography and SDS-PAGE analysis demonstrated that the puri-fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD+as a coenzyme to NADP+.The optimal temperature and pH of the TeXDH were 40 ℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26％of the initial enzyme activity,while the divalent metal ions Mg2+or Ca2+could recover the enzyme activity of TeXDH,reaching 103.32％and 110.69％of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn2+,Ni2+,Cu2+,Zn2+,Co2+,and Cd2+significantly inhibited the activity of TeXDH.ICP-MS and molecular doc-king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn2+ions and 1 mol/L Mg2+ion.Further-more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.

The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose-catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16 ℃ in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni-NTA affinity column.Size-exclusion chromatography and SDS-PAGE analysis demonstrated that the puri-fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD+as a coenzyme to NADP+.The optimal temperature and pH of the TeXDH were 40 ℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26％of the initial enzyme activity,while the divalent metal ions Mg2+or Ca2+could recover the enzyme activity of TeXDH,reaching 103.32％and 110.69％of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn2+,Ni2+,Cu2+,Zn2+,Co2+,and Cd2+significantly inhibited the activity of TeXDH.ICP-MS and molecular doc-king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn2+ions and 1 mol/L Mg2+ion.Further-more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors.

Objective:To investigate the completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients in the national multicenter real-world database.Methods:The prospective real-world study was conducted. The clinicopathological data of 1 074 patients who underwent surgical treatment for mid and low rectal cancer in 47 national medical institutions, including Peking Union Medical College Hospital et al, from May 12,2023 to May 11,2024 were collected. Observation indicators: (1) clinical characteristics of patients with mid and low rectal cancer; (2) initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer; (3) initial imaging evaluation of patients with mid and low rectal cancer; (4) imaging evaluation after neoadjuvant therapy for patients with mid and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M( Q1, Q3). Count data were described as absoluter numbers and/or percentages. Results:(1) Clinical characteristics of patients with mid and low rectal cancer. Of the 1 074 patients, there were 713 males and 361 females, aged 63(56,70)years. The body mass index of 1 074 patients was 24(21,26)kg/m 2.For American Society of Anesthesiologists classification, there were 147 cases of stage Ⅰ, 641 cases of stage Ⅱ, 157 cases of stage Ⅲ, 2 cases of stage Ⅳ, and there were 127 cases missing data. (2) Initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer. Of the 1 074 patients, there were 787 cases (73.28%) undergoing complete colonoscopy, and there were only 197 cases (18.34%) undergoing immunohistochemical evaluation of all four mismatch repair proteins. (3) Initial imaging evaluation of patients with mid and low rectal cancer. Of the 1 074 patients, there were 842(78.40%) patients completing magnetic resonance imaging (MRI) or ultrasound evaluation, and there were 914(85.10%) patients completing chest, abdomen, and pelvis enhanced computed tomography (CT) evaluation. In the 149 patients completing rectal ultrasound evaluation, there were 122 cases (81.88%) comple-ting T staging evaluation, and there were 81 cases (54.36%) completing N staging evaluation. In the 808 patients completing rectal MRI evaluation, there were 708 cases (87.62%) completing T staging evaluation, and there were 590 cases (73.02%) completing N staging evaluation. (4) Imaging evalua-tion after neoadjuvant therapy for patients with mid and low rectal cancer. Of the 388 patients with neoadjuvant therapy, there were 332 patients (85.57%) completing MRI or ultrasound evaluation, and there were 327 patients (84.28%) completing chest, abdomen, and pelvis enhanced CT evalua-tion. In the 70 patients completing rectal ultrasound evaluation, there were 65 cases (92.86%) com-pleting T staging evaluation, and there were 49 cases (70.00%) completing N staging evaluation. In the 327 patients completing rectal MRI evaluation, there were 246 cases (75.23%) completing T staging, and there were 228 cases (69.72%) completing N staging evaluation. Conclusion:The com-pletion rate of tumor imaging evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients on a national scale is relatively good.

Objective:To investigate the completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients in the national multicenter real-world database.Methods:The prospective real-world study was conducted. The clinicopathological data of 1 074 patients who underwent surgical treatment for mid and low rectal cancer in 47 national medical institutions, including Peking Union Medical College Hospital et al, from May 12,2023 to May 11,2024 were collected. Observation indicators: (1) clinical characteristics of patients with mid and low rectal cancer; (2) initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer; (3) initial imaging evaluation of patients with mid and low rectal cancer; (4) imaging evaluation after neoadjuvant therapy for patients with mid and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M( Q1, Q3). Count data were described as absoluter numbers and/or percentages. Results:(1) Clinical characteristics of patients with mid and low rectal cancer. Of the 1 074 patients, there were 713 males and 361 females, aged 63(56,70)years. The body mass index of 1 074 patients was 24(21,26)kg/m 2.For American Society of Anesthesiologists classification, there were 147 cases of stage Ⅰ, 641 cases of stage Ⅱ, 157 cases of stage Ⅲ, 2 cases of stage Ⅳ, and there were 127 cases missing data. (2) Initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer. Of the 1 074 patients, there were 787 cases (73.28%) undergoing complete colonoscopy, and there were only 197 cases (18.34%) undergoing immunohistochemical evaluation of all four mismatch repair proteins. (3) Initial imaging evaluation of patients with mid and low rectal cancer. Of the 1 074 patients, there were 842(78.40%) patients completing magnetic resonance imaging (MRI) or ultrasound evaluation, and there were 914(85.10%) patients completing chest, abdomen, and pelvis enhanced computed tomography (CT) evaluation. In the 149 patients completing rectal ultrasound evaluation, there were 122 cases (81.88%) comple-ting T staging evaluation, and there were 81 cases (54.36%) completing N staging evaluation. In the 808 patients completing rectal MRI evaluation, there were 708 cases (87.62%) completing T staging evaluation, and there were 590 cases (73.02%) completing N staging evaluation. (4) Imaging evalua-tion after neoadjuvant therapy for patients with mid and low rectal cancer. Of the 388 patients with neoadjuvant therapy, there were 332 patients (85.57%) completing MRI or ultrasound evaluation, and there were 327 patients (84.28%) completing chest, abdomen, and pelvis enhanced CT evalua-tion. In the 70 patients completing rectal ultrasound evaluation, there were 65 cases (92.86%) com-pleting T staging evaluation, and there were 49 cases (70.00%) completing N staging evaluation. In the 327 patients completing rectal MRI evaluation, there were 246 cases (75.23%) completing T staging, and there were 228 cases (69.72%) completing N staging evaluation. Conclusion:The com-pletion rate of tumor imaging evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients on a national scale is relatively good.

OBJECTIVETo investigate the function of dendritic cells (DC) of patients with immune related pancytopenia (IRP) and explore the role of DC in IRP.

METHODSThe expression of CD80 and CD86 on myeloid DC (mDC, Lin-HLA-DR(+) CD11c(+) cells) and plasmacytoid DC (pDC, Lin-HLA-DR(+) CD123(+) cells) of 65 IRP (37 untreated and 28 remitted) patients and 17 healthy controls were analyzed by flow cytometry.

RESULTSThe expression of CD86 on pDC was (82.47 ± 13.17)% in untreated group and (60.08 ± 14.29)% in remission group, which were significantly higher than that of controls (47.95 ± 18.59)% (P < 0.05), while the expression in untreated group was higher than that of remission group (P < 0.05). The expression of CD80 on pDC was (6.31 ± 4.49)% in untreated group, which was significantly higher than that of remitted patients (3.09 ± 2.93)% and controls (2.33 ± 2.25)% (P < 0.05). The expression of CD86 on mDC was (97.06 ± 4.82)% in untreated group and (91.35 ± 12.20)% in control group, while the expression in untreated group was higher than that of control group (P < 0.05). The expression of CD80 on mDC was (6.20 ± 5.44)% in untreated group and (3.97 ± 3.24)% in remission group, which were significantly higher than that of controls (1.86 ± 1.73)% (P < 0.05). The expression of CD86 on pDC was negatively correlated to Th1/Th2 (r = -0.733, P < 0.05), it was positively correlated to the antibody on membrane of BMMNC (r = 0.283, P < 0.05) and the quantity of CD5(+)B cells (r = 0.436, P < 0.05), while it was negatively correlated to the level of hemoglobin, platelets and white blood cells (r = -0.539, P < 0.05; r = -0.519, P < 0.05; r = -0.567, P < 0.05, respectively). The expression of CD80 on pDC was negatively correlated to the level of hemoglobin and platelets (r = -0.431, P < 0.05; r = -0.464, P < 0.05).

CONCLUSIONThe function of pDC in PB of IRP were strengthened, which was relevant to the immunopathogenesis of IRP.

Adolescent ; Adult ; Autoimmune Diseases ; complications ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; Case-Control Studies ; Child ; Child, Preschool ; Dendritic Cells ; metabolism ; Female ; Flow Cytometry ; Humans ; Male ; Middle Aged ; Pancytopenia ; blood ; etiology ; pathology ; Young Adult

OBJECTIVETo investigate the expression of Notch1 on the membrane of bone marrow CD38(+)CD138(+) plasma cells in the patients with multiple myeloma (MM), and explore the importance of Notch signaling pathway in the formation and progression of MM.

METHODSThirty three MM patients and 15 healthy controls were enrolled in this study. The expression of Notch1 on the membrane of bone marrow CD38(+)CD138(+) and CD38(+)CD138(-) plasma cells were analyzed by flow cytometry. The clinical data of MM patients were also analyzed.

RESULTSThe ratio of Notch1 on the membrane of CD38(+)CD138(+) plasma cells of MM patients was (60.21 ± 25.06)% which was significantly higher than those of CD38(+)CD138(-) plasma cells of MM patients (39.84 ± 18.94)% (P = 0.000) and controls (38.34 ± 19.39)% (P = 0.004). There was no statistical difference between the two latter groups (P > 0.05). The expression of Notch1 on CD38(+)CD138(+)plasma cells from 24 newly diagnosed MM patients was correlated to the level of malignant plasma cells in there bone marrow (r = 0.914, P = 0.000), serum level of lactate dehydrogenase (LDH) (r = 0.754, P = 0.007), and β(2)-MG(r = 0.716, P = 0.013). The ratio of Notch1 on the membrane of CD38(+)CD138(+) plasma cells of MM patients who had renal dysfunction was correlated to their abnormal serum creatinine levels. The expression of Notch1 on CD38(+)CD138(+) plasma cells from 17 MM patients who received VD (bortezamib and dexamethasone) chemotherapy was correlated to the ratio of plasma cell reduction after the first VD chemotherapy (r = 0.842, P = 0.000).

CONCLUSIONThe expression of Notch1 on the membrane of CD38(+)CD138(+) plasma cells of MM patients was significantly higher than those of CD38(+)CD138(-) plasma cells of MM patients and controls. Notch1 overexpressed plasma cells were sensitive to the early VD therapy, and correlated to the progression and long term outcome of MM.

ADP-ribosyl Cyclase 1 ; immunology ; Adult ; Aged ; Aged, 80 and over ; Bone Marrow ; metabolism ; Case-Control Studies ; Cell Count ; Female ; Humans ; Male ; Middle Aged ; Multiple Myeloma ; immunology ; metabolism ; Plasma Cells ; immunology ; metabolism ; Prognosis ; Receptor, Notch1 ; metabolism ; Syndecan-1 ; immunology

OBJECTIVETo investigate the expressions of STAT5 phosphorylation in CD34(+)CD38(-)CD123(+) bone marrow cells of the patients with myelodysplastic syndromes (MDS), and then evaluate the level of activation of STAT5 associated with cell proliferation in MDS clone cells.

METHODSThe bone marrow mononuclear cells (BMMNC) were extracted from 36 MDS patients and 14 normal controls. The mean fluorescence intensities (MFI) of phosphorylated STAT5(P-STAT5) in CD34(+)CD38(-)CD123(+) and CD34(+)CD38(-)CD123(-)cells, with or without the stimulation of 10 U/ml EPO, were examined by flow cytometry (FCM).

RESULTSWithout stimulation, the P-STAT5 MFI in CD34(+)CD38(-)CD123(+) cells of low/high risk MDS patients was 113.71 ± 67.22/173.05 ± 102.78, which was significantly higher than that of CD34(+)CD38(-)CD123(-) cells (58.84 ± 27.51/68.99 ± 50.42, P < 0.01, P < 0.05) and the normal controls CD34(+)CD38(-)CD123(-) cells (63.06 ± 21.06, P < 0.05), there was no significant difference between the CD34(+)CD38(-)CD123(-) cells of MDS patients and the normal control CD34(+)CD38(-)CD123(-) cells; With the EPO stimulation, the P-STAT5 MFI in CD34(+)CD38(-)CD123(+) cells of low/high risk MDS patients was 144.04 ± 58.11/239.45 ± 152.05, which was significantly higher than that of CD34(+)CD38(-)CD123(-) cells (68.41 ± 25, 10/64.21 ± 23.43, P < 0.01) and the normal controls CD34(+)CD38(-)CD123(-) cells (75.21 ± 27.02, P < 0.01), there was no significant difference between the CD34(+)CD38(-)CD123(-) cells of MDS patients and the normal control CD34(+)CD38(-)CD123(-) cells; The P-STAT5 MFI in the CD34(+)CD38(-)CD123(+) cells of low/high risk MDS patients with or without EPO stimulation were 21.80/28.86, which was significantly higher than that of CD34(+)CD38(-)CD123(-) cells (7.42/5.50, P < 0.01, P < 0.05) and the normal controls CD34(+)CD38(-)CD123(-) cells (6.39, P < 0.05), there was no significant difference between the CD34(+)CD38(-)CD123(-) cells of MDS patients and the normal controls CD34(+)CD38(-)CD123(-) cells; There was no significant difference of P-STAT5 MFI with or without EPO stimulation and the increased P-STAT5 MFI between the CD34(+)CD38(-)CD123(+) cells of low and high risk MDS.

CONCLUSIONSTAT5 associated with cell proliferation was activated in CD34(+)CD38(-)CD123(+) bone marrow cells in MDS, which had more significant reactions to EPO than CD34(+)CD38(-)CD123(-) cells, indicating that CD34(+)CD38(-)CD123(+) bone marrow cells might be the real malignant MDS clone cells in MDS.

Adult ; Aged ; Aged, 80 and over ; Antigens, CD34 ; metabolism ; Bone Marrow Cells ; cytology ; metabolism ; Cell Proliferation ; Cells, Cultured ; Female ; Flow Cytometry ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes ; metabolism ; pathology ; Phosphorylation ; STAT5 Transcription Factor ; metabolism

This study was aimed to explore whether the perforin gene 1 (PRF1) mutation is the basis of genetic susceptibility to pathogenesis of acquired severe aplastic anemia (SAA). DNA exon2 and exon3 of PRF1 gene in peripheral blood mononuclear cells in 31 SAA patients and 15 normal controls were amplified by PCR; the sequencing was performed by using ABI pRISM 373OXL sequencer; the mutation loci were sought through checking sequences with GenBank-reported sequences; after the mutation sequences were found, those were cloned into M13 phage vector, then the corresponding sequences of gained 2 chromosomes were sequenced respectively to determine the distribution of different mutations on chromosomes. The results showed that (1) one homozygous mutation (822 C > T, synonymous mutation) and one heterozygous mutation (907 G > A, methionine 303 valine) were found in PRF1 coding region of 2 SAA patients. These mutations were not detected in normal controls. (2) 1 SNP (rs885822) in the coding region was detected in SAA patients and controls, and the heterozygosity rate between the 2 groups was different (p < 0.05). It is concluded that perforin gene mutation may be one risk factor in the aberrant proliferation and activation of cytotoxic T cells in pathogenesis of a part of patients with aplastic anemia.
Adolescent ; Adult ; Aged ; Anemia, Aplastic ; genetics ; Base Sequence ; Case-Control Studies ; Child ; Child, Preschool ; Female ; Genetic Predisposition to Disease ; Heterozygote ; Humans ; Male ; Middle Aged ; Mutation ; Perforin ; Pore Forming Cytotoxic Proteins ; genetics ; Young Adult

This study was purposed to investigate the BCL-2/IgH gene rearrangement in major break point region (MBR) and IgH gene rearrangements of patients with non-Hodgkin's lymphoma (NHL), and explore their significance for improving early diagnosis and accurately evaluating chemotherapy effect. DNA for BCL-2/IgH and IgH gene assays was extracted from bone marrow mononuclear cells in 70 cases of lymphoma (60 cases of B-NHL and 10 cases of T-NHL), 7 cases of lymph node inflammatory and 20 healthy controls. The BCL-2/IgH, IgH gene rearrangements were assayed by polymerase chain reaction (PCR), the assayed results were compared with results of pathological biopsy; the factors related with occurrence of these 2 kinds of gene rearrangement were analyzed and the dynamic changes of BCL-2/IgH and IgH gene rearrangements after chemotherapy were compared, the chemotherapy effect was evaluated. The results indicated that (1) BCL-2/IgH gene rearrangement in bone marrow mononuclear cells was observed in 10 cases out of 30 DLBCL cases (33.3%), and was more frequent than that in 30 other B-NHL cases (6.7%), 10 T-NHL cases (0%), 7 lymph nodes inflammatory cases (0%) and 20 healthy controls (5%) (p < 0.05). (2) the quantity of rearranged BCL-2/IgH gene of 8 DLBCL cases reduced from 0.59 to 0.16 (p < 0.05) after 2 courses of R-CHOP chemotherapy and completely disappeared after 6 courses of R-CHOP chemotherapy. (3) 81.8% patients with BCL-2/IgH gene rearrangement showed high serum LDH level, while it was observed in 28.6% patients without this gene rearrangement (p < 0.05). Lymphoma staging, systemic symptoms, β(2)-MG level, bone marrow involvement, infiltration of liver and spleen were not significantly correlated with BCL-2/IgH gene rearrangement. (4) IgH gene rearrangement was found in 9 cases out of 20 DLBCL patients (all newly diagnosed patients) (45%), IgH rearrangement was observed in 14 cases out of 30 other B-NHL (all newly diagnosed or relapsed patients, except patients with DLBCL) (46.7%) and there was no statistical difference between these 2 groups, however IgH rearrangement all were not observed in 20 healthy persons, 10 T-NHL cases and 7 lymph nodes inflammatory cases. (5) the quantity of rearranged IgH gene in 7 DLBCL cases was reduced from 0.42 to 0.13 after one course of R-CHOP chemotherapy (p < 0.05) and completely disappeared after 2 courses of R-CHOP chemotherapy. (6) 90% patients with IgH gene rearrangement had high serum LDH level, while it was found in 30% patients without this gene rearrangement (p < 0.05). Lymphoma staging, systemic symptoms, β(2)-MG levels, bone marrow involvement, infiltrations liver and spleen all were not significantly correlated with IgH gene rearrangement. It is concluded that the BCL-2/IgH and IgH gene rearrangements may be used as specific indicators in early diagnosis and accurate evaluation of therapy efficacy in B-NHL, these 2 kind of rearrangement correlate with LDH level. The BCL-2/IgH gene rearrangement is more specific for in DLBCL.
Adult ; Aged ; Aged, 80 and over ; Bone Marrow Cells ; Case-Control Studies ; Female ; Gene Rearrangement, B-Lymphocyte, Heavy Chain ; genetics ; Humans ; Lymphoma, Non-Hodgkin ; blood ; genetics ; Male ; Middle Aged ; Young Adult

OBJECTIVETo study the expressions of erythropoietin receptor (EPOR) and thrombopoietin receptor (TPOR) on CD34+ CD59- and CD34+ CD59+ bone marrow (BM) cells from patients with paroxysmal nocturnal hemoglobinuria (PNH).

METHODS(1) The expressions of EPOR and TPOR on CD34+ CD59- and CD34+ CD59- BM cells from 26 PNH patients and 16 normal controls were examined by flow cytometry (FCM). (2) The mRNA expression of the EPOR and the TPOR in BM mononuclear cells (BMMNC) from 25 PNH patients and 13 normal controls were examined by RT-PCR.

RESULTS(1) The percentage of EPOR positive cells in PNH CD34+ CD59+ BMMNC [(30.67 +/- 18.30)%] was significantly higher than that in PNH CD34+ CD59- BMMNC [(8.05 +/- 3.51)%] (P < 0.01) and than that in control CD34+ CD59+ BMMNC [(8.24 +/- 6.51)%] (P < 0.01), but there was no obvious difference between the CD34+ CD59-BMMNC in PNH and CD34+ CD59+ BMMNC in control. (2) The percentage of TPOR positive cells in PNH CD34+ CD59+ BMMNC [(28.15 +/- 17.75)%] was significantly higher than that in PNH CD34+ CD59-BMMNC [(15.65 +/- 14.45)%] (P < 0.05) and than that in control CD34+ CD59+ BMMNC [(10.77 +/- .39)%] (P < 0.01), but there was no obvious difference between the CD34+ CD59- BMMNC in PNH and CD34+ CD59+ BMMNC in control. (3) There was no statistic difference in EPOR mRNA and TPOR mRNA expressions in BMMNCs between PNH patients group [(0.41 +/- 0.37) and (0.32 +/- 0.19), respectively] and control group [(0.47 +/- 0.33) and (0.40 +/- 0.29), respectively].

CONCLUSIONThe expression of EPOR and TPOR of PNH patients on BM CD34+ CD59+ cells are significantly higher than those on BM CD34+ CD59- cells. The difference may be due to abnormal transcription of both receptor coding genes.

Adult ; Bone Marrow Cells ; metabolism ; CD59 Antigens ; metabolism ; Case-Control Studies ; Cells, Cultured ; Female ; Flow Cytometry ; Hemoglobinuria, Paroxysmal ; metabolism ; Humans ; Male ; Middle Aged ; Receptors, Erythropoietin ; metabolism ; Receptors, Thrombopoietin ; metabolism ; Young Adult