OBJECTIVETo investigate whether Shen-Fu Injection (, SFI) reduces post-resuscitation immune dysfunction in a porcine model of cardiac arrest by modulating apoptosis of regulatory T lymphocytes (Treg) in the spleen.

METHODSAfter 8-min untreated ventricular fibrillation and 2-min basic life support, 24 pigs were divided into 3 groups with a random number table, i.e. SFI group, epinephrine (EP) group, and saline (SA) group (8 in each group), which received central venous injection of SFI (1.0 mL/kg), EP (0.02 mg/kg) and SA, respectively. The same procedure without CA initiation was achieved in the sham-operated (sham) group (n=6). After successful return of spontaneous circulation (ROSC), apoptosis rate of splenic Treg was detected by flow cytometry; and the mRNA expression of forkhead/winged helix transcription factor (Foxp3) of splenic Treg was detected by real time-polymerase chain reaction; and the levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in porcine splenic Treg were detected by using enzyme-linked immunosorbent assay (ELISA).

RESULTSCompared with the sham group, the apoptosis rate of Treg was significantly decreased, and the levels of Foxp3 mRNA expression, IFN-γ, IL-4 and IFN-γ/IL-4 were increased in the SA group (P<0.05 or P<0.01). Compared with the EP and SA groups, SFI treatment increased the apoptosis rate of Treg and reduced the levels of Foxp3 mRNA expression, IFN-γ and IFN-γ/IL-4 (P<0.05).

CONCLUSIONSSFI has signifificant effects in attenuating post-resuscitation immune dysfunction by modulating apoptosis of Treg in the spleen.

Animals ; Apoptosis ; drug effects ; Cardiopulmonary Resuscitation ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Forkhead Transcription Factors ; genetics ; metabolism ; Heart Arrest ; drug therapy ; immunology ; pathology ; physiopathology ; Hemodynamics ; drug effects ; Injections ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Lymphocyte Subsets ; drug effects ; metabolism ; Male ; Oxygen ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Spleen ; immunology ; Survival Analysis ; Swine ; Swine, Miniature ; T-Lymphocytes, Regulatory ; drug effects ; immunology

OBJECTIVE: To explore the effects of pure adenoidectomy,adenoidectomy with partial tonsillectomy,and adenoidectomy with total tonsillectomy on humoral and cellular immunity of children with OSAHS. METHOD: The children with OSAHS diagnosed by polysomnography were divided into pure adenoidectomy group(group A),adenoidectomy with partial tonsillectomy group(group B), and adenoidectomy with total tonsillectomy(group C), and there were 50 cases in each group. The serum IgG, IgA, IgM level and peripheral blood T cell subgroup per-centage were detected at 6 months preoperatively and postoperatively. Tonsil grading and polysomnography wereconducted, recording symptoms improvement situation at postoperative 6 months. RESULT: There was no statisticallysignificant difference compared with preoperative(P>0. 05) in humoral immunity and cellular immunity index ofpostoperative 6 months. There was no significani difference(P>C. 05) in curative effect among three groups in the 6th month post-operatively. CONCLUSION All of these three surgical procedures had no obvious effect on humoral orcellular immune function in children, and could effectively treat children OSAHS.
Adenoidectomy ; Antibodies ; blood ; Child ; Humans ; Immunity, Cellular ; Immunity, Humoral ; Palatine Tonsil ; pathology ; Polysomnography ; Postoperative Period ; Sleep Apnea, Obstructive ; immunology ; surgery ; T-Lymphocyte Subsets ; cytology ; Tonsillectomy

OBJECTIVETo investigate the characteristics and clinical significance of changes in gamma delta T cells in patients with chronic hepatitis B (CHB), including during the immune tolerant (IT) phase and the immune activated (IA) phase.

METHODSFlow cytometry was used to analyze the frequencies and absolute numbers of γδT cells and their subsets in peripheral blood and in liver from 80 CHB cases, including 20 IT carriers and 60 IA patients. Blood samples were obtained from all CHB cases and 5 healthy controls (HCs). Liver biopsies were collected from 22 IA patients and 5 IT carriers undergoing diagnosis, and from the 5 HCs.

RESULTSCompared to HCs and IT carriers, the IA patients displayed significantly lower levels of peripheral and intrahepatic γδT cells as well as the Vδ2 subsets. The levels of peripheral and intrahepatic VγδT cells were closely associated with the liver histological activity index and serum alanine aminotransferase levels.

CONCLUSIONγδT cells, especially the Vδ2 subsets, may play a protective role in decreasing liver damage in CHB patients.

Alanine Transaminase ; blood ; Case-Control Studies ; Flow Cytometry ; Hepatitis B, Chronic ; immunology ; pathology ; Humans ; Liver Cirrhosis ; immunology ; T-Lymphocyte Subsets ; cytology

Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play crucial roles in a variety of diseases, including autoimmunity, infectious diseases, and cancers. However, little is known about the roles of these invariant T cells in acute cholecystitis. The purposes of this study were to examine the levels of MAIT cells and NKT cells in patients with acute cholecystitis and to investigate potential relationships between clinical parameters and these cell levels. Thirty patients with pathologically proven acute cholecystitis and 47 age- and sex-matched healthy controls were enrolled. Disease grades were classified according to the revised Tokyo guidelines (TG13) for the severity assessment for acute cholecystitis. Levels of MAIT and NKT cells in peripheral blood were measured by flow cytometry. Circulating MAIT and NKT cell numbers were significantly lower in acute cholecystitis patients than in healthy controls, and these deficiencies in MAIT cells and NKT cell numbers were associated with aging in acute cholecystitis patients. Notably, a reduction in NKT cell numbers was found to be associated with severe TG13 grade, death, and high blood urea nitrogen levels. The study shows numerical deficiencies of circulating MAIT and NKT cells and age-related decline of these invariant T cells. In addition, NKT cell deficiency was associated with acute cholecystitis severity and outcome. These findings provide an information regarding the monitoring of these changes in circulating MAIT and NKT cell numbers during the course of acute cholecystitis and predicting prognosis.
Aged ; Antibodies, Monoclonal/immunology ; Case-Control Studies ; Cholecystitis, Acute/*diagnosis/immunology/pathology ; Female ; Flow Cytometry ; Humans ; Leukocytes, Mononuclear/cytology ; Male ; Middle Aged ; Natural Killer T-Cells/*cytology/immunology ; Patients ; Prognosis ; Severity of Illness Index ; T-Lymphocyte Subsets/*cytology/immunology

OBJECTIVETo observe the effects of astragalus polysaccharide (AP) on the intestinal mucosal morphology, level of secretory IgA (s-IgA) in intestinal mucus, and distribution of T lymphocyte subsets in Peyer's patch in rats with severe scald injury.

METHODSOne hundred and thirty SD rats were divided into sham injury group (SI, sham injured, n = 10), scald group (S, n = 30), low dosage group (LD, n = 30), moderate dosage group (MD, n = 30), and high dosage group (HD, n = 30) according to the random number table. Rats in the latter 4 groups were inflicted with 30% TBSA full-thickness scald on the back. From post injury hour 2, rats in groups LD, MD, and HD were intraperitoneally injected with 0.5 mL AP solution with the dosage of 100, 200, and 300 mg/kg each day respectively, and rats in group S were injected with 0.5 mL normal saline instead. Ten rats from group SI immediately after injury and 10 rats from each of the latter 4 groups on post injury day (PID) 3, 7, 14 were sacrificed, and their intestines were harvested. The morphology of ileal mucosa was examined after HE staining; the level of s-IgA in ileal mucus was determined with double-antibody sandwich ELISA method; the proportions of CD3⁺, CD4⁺, CD8⁺ T lymphocytes in Peyer's patches of intestine were determined with flow cytometer, and the proportion of CD4⁺ to CD8⁺ was calculated. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and SNK test.

RESULTS(1) Villi in normal form and intact villus epithelial cells were observed in rats of group SI immediately after injury, while edema of villi and necrosis and desquamation of an enormous amount of villi were observed in groups with scalded rats on PID 3, with significant infiltration of inflammatory cells. On PID 7, no obvious improvement in intestinal mucosal lesion was observed in groups with scalded rats. On PID 14, the pathology in intestinal mucosa of rats remained nearly the same in group S, and it was alleviated obviously in groups LD and MD, and the morphology of intestinal mucosa of rats in group HD was recovered to that of group SI. (2) On PID 3, 7, and 14, the level of s-IgA in intestinal mucus significantly decreased in groups S, LD, MD, and HD [(43 ± 5), (45 ± 5), (46 ± 5) µg/mL; (47 ± 5), (48 ± 5), (49 ± 6) µg/mL; (50 ± 6), (51 ± 5), (52 ± 5) µg/mL; (53 ± 6), (54 ± 5), (55 ± 5) µg/mL] as compared with that of rats in group SI immediately after injury [(69 ± 4) µg/mL, with P values below 0.05]. The level of s-IgA in intestinal mucus of rats in group MD was significantly higher than that in group S at each time point (with P values below 0.05), and that of group HD was significantly higher than that in groups S and LD at each time point (with P values below 0.05). (3) Compared with those of rats in group SI immediately after injury, the proportions of CD3⁺ T lymphocytes and CD4⁺ T lymphocytes significantly decreased in groups with scalded rats at each time point (with P values below 0.05), except for those in group HD on PID 14. The proportion of CD4⁺ T lymphocytes of rats in group LD was significantly higher than that in group S on PID 3 (P < 0.05). The proportions of CD3⁺ T lymphocytes and CD4⁺ T lymphocytes were significantly higher in groups MD and HD than in groups S and LD (except for the proportion of CD4⁺ T lymphocytes in group MD on PID 3 and 14) at each time point (with P values below 0.05). The proportion of CD3⁺ T lymphocytes on PID 7 and 14 and that of CD4⁺ T lymphocytes on PID 3 were significantly higher in group HD than in group MD (with P values below 0.05). Compared with that of rats in group SI immediately after injury, the proportion of CD8⁺ T lymphocytes significantly increased in the other 4 groups at each time point (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group LD on PID 7 and 14 and groups MD and HD at each time point than in group S (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group MD on PID 7 and 14 and group HD at each time point than in group LD (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group HD on PID 7 and 14 than in group MD (with P values below 0.05). On PID 3, 7, and 14, the proportion of CD4⁺ to CD8⁺ was significantly lower in groups S, LD, MD, and HD (0.65 ± 0.11, 0.68 ± 0.13, 0.73 ± 0.22; 0.76 ± 0.15, 0.78 ± 0.14, 0.90 ± 0.10; 0.85 ± 0.21, 0.89 ± 0.18, 1.08 ± 0.19; 0.99 ± 0.20, 1.05 ± 0.21, 1.25 ± 0.23) as compared with that of rats in group SI immediately after injury (1.74 ± 0.20, with P values below 0.05). The proportion of CD4⁺ to CD8⁺ was significantly higher in rats of group HD than in group MD on PID 7 (P < 0.05), and the proportion was significantly higher in these two groups than in group S at each time point (with P values below 0.05). The proportion of CD4⁺ to CD8⁺ was significantly higher in rats of group MD on PID 14 and group HD at each time point than in group LD (with P values below 0.05). Compared within each group, the proportions of CD3⁺, CD4⁺, CD8⁺ T lymphocytes and the proportion of CD4⁺ to CD8⁺ of rats in groups LD, MD, and HD showed a trend of gradual elevation along with passage of time.

CONCLUSIONSAP can improve the injury to intestinal mucosa and modulate the balance of T lymphocyte subsets in Peyer's patch in a time- and dose-dependent manner, and it can promote s-IgA secretion of intestinal mucosa in a dose-dependent manner.

Animals ; Astragalus Plant ; adverse effects ; Burns ; immunology ; pathology ; physiopathology ; Dose-Response Relationship, Drug ; Immunity, Mucosal ; Immunoglobulin A ; metabolism ; Intestinal Mucosa ; metabolism ; physiology ; Intestine, Small ; metabolism ; Peyer's Patches ; immunology ; physiopathology ; Polysaccharides ; Rats ; Rats, Sprague-Dawley ; Soft Tissue Injuries ; T-Lymphocyte Subsets ; immunology

OBJECTIVETo investigate the role played by γδ T cells in acute liver injury using the concanavalin A (ConA)-induced liver injury mouse model.

METHODSAcute liver injury was induced by intravenous injection of 10 mug/g of ConA into male C57BL/6J mice with wild-type or T cell receptor-γ knockout (TCR δ-/-) genetic backgrounds. Mice injected with PBS alone served as negative controls. The degree of liver damage was assessed by measuring serum levels of transaminase and cytokines at post-injection hours 3, 6, 12, 24, 48, and 72. The percentage of γδ T cells and proportions of different subsets in liver lymphocytes were measured by flow cytometry.

RESULTSThe TCR δ-/- mice showed significantly higher levels of the inflammatory cytokines IFN-γ, TNFα and IL-4 than the wild-type mice at post-injection hour 3. The percentage of liver γδ T cells increased with increased injury degree, and the extent of increase was significantly higher in the TCR δ-/- mice than the wild-type mice (post-injection hour 6: 6302.61+/-592.06 vs. 1319.26+/-355.48, 12: 6569.44+/-1060.98 vs. 3415.53+/-343.90, 24: 6514.29+/-757.26 vs. 2062.73+/-365.67, 48: 1262.61+/-558.07 vs. 113.66+/-113.26, and 72: 226.54+/-98.20 vs. 42.35+/-21.51 U/L; all P less than 0.05). In addition, compared to the negative control mice, the ConA-induced mice showed a higher proportions of Vγ4 γδ T cells to total γδ T cells (17.78+/-2.95 vs. 25.26+/-2.43) and to total liver lymphocytes (0.47+/-0.07 vs. 0.66+/-0.05). Similarly, compared to the negative control mice, the ConA-induced mice showed a higher proportion of Vγ1 γδ T cells to total γδ T cells (38.37+/-6.10 vs. 50.19+/-5.52) but the proportion to total liver lymphocytes was not significantly different among the groups (0.76+/-0.18 vs. 0.78+/-0.25). Reinfusion of Vγ4 γδ T lymphocytes into TCR δ-/- mice led to lower serum ALT levels than reinfusion of Vγ1 γδ T lymphocytes (5054.10+/-1748.51 vs. 12333.56+/-663.535 U/L).

CONCLUSIONγδ T cells play a protective role in ConA-induced liver injury and this effect maybe mediated by the Vγ4 γδ T cell subset.

Animals ; Chemical and Drug Induced Liver Injury ; immunology ; pathology ; Concanavalin A ; toxicity ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Liver ; drug effects ; immunology ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Receptors, Antigen, T-Cell, gamma-delta ; metabolism ; T-Lymphocyte Subsets ; immunology ; Tumor Necrosis Factor-alpha ; immunology

OBJECTIVETo investigate the relationship between the immunity and invasiveness in differentiated thyroid cancer (DTC).

METHODSTotally 74 DTC who were treated in Peking Union Medical College Hospital from September 2012 to December 2012 were enrolled in this study. These 74 patients were divided into membrane invasion group (n=36) and without membrane invasion group (n=38); also, they were divided into distant metastasis group (n=18) and without distant metastasis group (n=56). Natural killer (NK) cells and T-cell subsets were chosen as indicators for cellular immunity to investigate the correlation between cellular immunity and invasiveness in DTC.

RESULTSUnivariate analysis showed that the membrane invasion (Χ(2)=12.175, P=0.000) and distant metastasis (Χ(2)=8.139, P=0.006) correlated with cell immunity, whereas distant metastasis correlated with lymphocytic thyroiditis (Χ(2)=7.094, P=0.008). Further investigation shows that distant metastasis was associated with the percentage of CD8+T cell subgroup (Χ(2)=5.429, P=0.020), and membrane invasion was significantly associated with NK cells (Χ(2)=2.445, P=0.018) and CD4/CD8 disorder subgroup (Χ(2)=8.079, P=0.002). Multivariate analysis showed that cell immunity disorder was a risk factor for membrane invasion [OR=5.701,95%CI(2.075~15.666), P=0.001] and distant metastasis [OR=5.063,95%CI (1.571~16.320), P=0.008]. Further analysis showed that CD8+T cell was a risk factor for metastasis [OR=2.236,95%CI( 1.084~4.613), P=0.029], and CD4/CD8 disorders were the risk factors for membrane invasion [OR=2.802,95%CI(1.257~6.244), P=0.012].

CONCLUSIONCell immunity in thyroid cancer has close relationship with membrane invasion and distant metastasis, especially when the percentage of CD8+T cells decreases and when the NK cells and CD4/CD8 are abnormal, which may lead to membrane invasion and distant metastasis.

Adenocarcinoma ; immunology ; pathology ; Adolescent ; Adult ; Child ; Female ; Humans ; Immunity, Cellular ; Killer Cells, Natural ; immunology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Invasiveness ; T-Lymphocyte Subsets ; immunology ; Thyroid Neoplasms ; immunology ; pathology ; Young Adult

OBJECTIVETo investigate the changes of relative telomere length (RTL) of peripheral blood (PB) CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺T lymphocytes, CD19⁺B lymphocytes and bone marrow (BM) CD34⁺ cells and its association with disease severity in untreated patients with immuno-related pancytopenia (IRP).

METHODSThe PB CD3⁺ , CD3⁺ CD4⁺ , CD3⁺ CD8⁺ T lymphocytes, CD19⁺ B lymphocytes, and BM CD34⁺ cells were purified by magnetic activated cell sorting (MACS), and RTL were measured with flow-fluorescence in situ hybridization (FLOW-FISH).

RESULTSThe RTL of CD3⁺, CD3⁺CD4⁺ , and CD3⁺CD8⁺T lymphocytes in untreated IRP patients were (27.754 ± 16.323)%, (7.526 ± 3.745)% and (25.854 ± 14.789)%, respectivly, which were significantly shorter than those in healthy-controls (54.555 ± 19.782)%, (12.096 ± 2.805)%, and (38.367 ± 4.626)% (P<0.05). The RTL of CD19⁺ lymphocytes in untreated IRP patients was (22.136 ± 16.142)%, which was significantly shorter than that in healthy controls (42.846 ± 16.353)% (P<0.01). There was no significant difference of BM CD34⁺ cells RTL between the untreated IRP patients (22.528 ± 21.601)% and the healthy controls (23.936 ± 19.822)% (P>0.05). There were significantly positive correlations between the RTL of B lymphocytes and the count of white blood cell (r=0.706, P=0.015). There were negative correlations between RTL of B lymphocytes and the clinical symptoms (r=-0.613, P=0.045) and positive correlations with therapeutic effect (r=0.775, P=0.005).

CONCLUSIONThe shorter RTL of CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, CD19⁺ lymphocytes, and the normal RTL of BM CD34⁺ cells in untreated IRP patients were identified, which might imply that IRP is a type of acquired autoimmune diseases.

Adolescent ; Adult ; B-Lymphocyte Subsets ; immunology ; Child ; Female ; Humans ; Lymphocytes ; ultrastructure ; Male ; Middle Aged ; Pancytopenia ; immunology ; pathology ; T-Lymphocyte Subsets ; immunology ; Telomere ; ultrastructure ; Young Adult

OBJECTIVETo investigate the change of lymphocyte subsets before and after chemotherapy in colorectal carcinoma patients.

METHODSTwenty-one peripheral blood lymphocyte subsets from 62 colorectal carcinoma patients before and after FOLFOX4(including oxaliplatin, 5-fluorouracil and leucovorin) , FOLFRI(including irinotecan, 5-fluorouracil and leucovorin) , or XELOX(including oxaliplatin and capecitabine) regimen chemotherapy were examined by flow cytometry.The differences of these lymphocyte subsets were analyzed.

RESULTSAfter chemotherapy, the percentages of CD3(+), CD3(+)CD8(+), CD29(+), CD4(+)CD29(+), and CD4(+)CD25(+) cells in peripheral blood of colorectal carcinoma patients increased significantly, while the percentages of CD19(+) and human leukocyte antigen(locus) DR(HLA-DR) (+) cells decreased significantly(P<0.05) .The results of subgroup analysis showed that the patients' CD3(+)CD8(+) and CD4(+)CD25(+) cells increased significantly, CD19(+) and HLA-DR(+) cells decreased significantly after FOLFOX4 regimen chemotherapy(P<0.05) ;CD3(+)CD8(+) cells increased significantly and CD19(+) cells decreased significantly after XELOX regimen chemotherapy(P<0.05) ;while after FOLFRI regimen chemotherapy, there were no significant changes in all 21 lymphocyte subsets(P>0.05) . CD3(+), CD3(+)CD8(+), memory T lymphoctye(45RO(+)) , and CD4(+)CD45RO(+) cells increased significantly(P<0.05) in patients who received no more than 4 cycles of chemotherapy. However, in patients that received 5 to 8 cycles and more than 9 cycles chemotherapy, we only found significant decrease of HLADR(+) cells and significant increase of CD29(+) cells, respectively(P<0.05) .

CONCLUSIONSThe humoral immunity is attenuated after chemotherapy in colorectal carcinoma patients. FOLFOX4 may suppress the cellular immunity.Chemotherapy that is less than 4 cycles will strengthens the cellular immunity by modulating body immunity arrangement;however, along with the increase of chemotherapy cycles, the cellular immunity gradually declines in these patients.

Adult ; Aged ; Aged, 80 and over ; Antigens, CD19 ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; administration & dosage ; Camptothecin ; administration & dosage ; analogs & derivatives ; Colorectal Neoplasms ; drug therapy ; immunology ; Deoxycytidine ; administration & dosage ; analogs & derivatives ; Female ; Fluorouracil ; administration & dosage ; analogs & derivatives ; Humans ; Leucovorin ; administration & dosage ; Lymphocyte Subsets ; pathology ; Male ; Middle Aged ; Organoplatinum Compounds ; administration & dosage

OBJECTIVETo analyze the correlation between the pneumoconiosis severity and the cytokines levels in serum and bronchoalveolar lavage fluid (BALF) or blood T cell subsets.

METHODSThe subjects were divided into five groups: control group (6 cases), group exposed to dusts (6 cases) and 3 pneumoconiosis groups (36 in stage I, 12 in stage II and 10 in stage III). ELISA was used to detect IL-6, sIL-2R and TNF-α levels in serum and BALF. The subsets of blood T cells were classified by flow cytometer.

RESULTSAs compared with control group and group exposed to dusts, the levels of serum IL-6 and sIL-2R in patients with II or III stages significantly increased, which were positively correlated with pneumoconiosis stages (r(1) = 0.74, r(2) = 0.81, P < 0.05). The level of serum TNF-α significantly decreased in patients with III stages, as compared with control group and group exposed to dusts. There was a negative correlation between serum TNF-α level and pneumoconiosis severity (r = -0.58, P < 0.05). There was a positive correlation between the levels of IL-6, sIL-2R and TNF-α in BALF and the levels of IL-6, sIL-2R and TNF-α in serum (r(1) = 0.77, r(2) = 0.96 and r(3) = 0.88, P < 0.05). The proportion of CD(4)(+)T cells and the ratio of CD(4)(+)/CD(8)(+) decreased dramatically in patients with II and III stages. But there was no correlation between these values and disease severity.

CONCLUSIONThe immune function in Th cell was inhibited. The levels of IL-6, sIL-2R and TNF-α in serum and BALF were associated with the severity of pneumoconiosis.

Bronchoalveolar Lavage Fluid ; immunology ; CD4-CD8 Ratio ; Case-Control Studies ; Cytokines ; blood ; metabolism ; Female ; Humans ; Interleukin-6 ; blood ; metabolism ; Male ; Pneumoconiosis ; immunology ; metabolism ; pathology ; Receptors, Interleukin-2 ; blood ; metabolism ; T-Lymphocyte Subsets ; Tumor Necrosis Factor-alpha ; blood ; metabolism