Central neural mechanism of increased pain sensitivity induced by nicotine abstinence / 生理学报

Nicotine is the main addictive component in cigarettes that motivates dependence on tobacco use for smokers and makes it difficult to quit through regulating a variety of neurotransmitter release and receptor activations in the brain. Even though nicotine has an analgesic effect, clinical studies demonstrated that nicotine abstinence reduces pain threshold and increases pain sensitivity in smoking individuals. The demand for opioid analgesics in nicotine abstinent patients undergoing surgery has greatly increased, which results in many side effects, such as nausea, vomiting, and respiratory depression, etc. In addition, these side effects would hinder patients' physical and psychological recovery. Therefore, identifying the neural mechanism of the increase of pain sensitivity induced by nicotine abstinence and deriving a way to cope with the increased demand for postoperative analgesics would have enormous basic and clinical implications. In this review, we first discussed different experimental pain stimuli (e.g., cold, heat, and mechanical pain)-induced pain sensitivity changes after a period of nicotine dependence/abstinence from both animal and human studies. Then, we summarized the effects of the brain neurotransmitter release (e.g., serotonin, norepinephrine, endogenous opioids, dopamine, and γ-aminobutyric acid) and their corresponding receptor activation changes after nicotine abstinence on pain sensitivity. Finally, we discussed the limits in recent studies. We proposed that more attention should be paid to human studies, especially studies among chronic pain patients, and functional magnetic resonance imaging might be a useful tool to reveal the mechanisms of abstinence-induced pain sensitivity changes. Besides, considering the influence of duration of nicotine dependence/abstinence and gender on pain sensitivity, we proposed that the effects of nicotine abstinence and individual differences (e.g., duration of abstinence from smoking, chronic/acute abstinence, and gender) on abstinence-induced pain sensitivity should be fully considered in formulating pain treatment protocols. In summary, this paper could deepen our understanding of nicotine abstinence-induced pain sensitivity changes and its underlying neural mechanism, and could also provide effective scientific theories to guide clinical pain diagnosis and treatment, which has important clinical significance.

Influence of intra-bone marrow infusion of donor lymphocytes on development of graft-versus-host disease and level of IL-4 and IFN-gamma in peripheral blood / 中国实验血液学杂志

To investigate the effect of donor lymphocyte infusion (DLI) by intra-bone marrow (IBM) routes on the incidence of graft-versus-host disease(GVHD), level of IL-4 and IFN-gamma after allogeneic peripheral hematopoietic stem cell transplantation (allo-PBSCT). Female C57BL/6 mice as recipients received total body irradiation (TBI) on day 0, followed by injection of peripheral hematopoietic stem cells from mobilized donor of male BALB/c with the granulocyte-colony stimulating factor (rhG-CSF), and DLI was performed via ether IV or IBM routes. The severity of GVHD was compared in recipients received allogeneic IBM-DLI with those mice received IV-DLI; at 14 days after DLI, the levels of IL-4 and interferon (IFN)-gamma were tested by ELISA. The results showed that as compared with IV-DLI group the frequency and severity of GVHD were reduced in IBM-DLI (p < 0.01); the level of IL-4 significantly increased, while the level of IFN-gamma decreased in group IV-DLI (p < 0.01). It is concluded that IBM-DLI declines the incidence and severity of GVHD after allo-PBSCT.

Effect of recipient mouse splenocytes taken orally by donor mouse on GVHD after splenocyte transplantation / 中国实验血液学杂志

This study was aimed to explore whether the GVHD in mice can be ameliorated and the GVL effect in mice can be reserved by transfusion of lymphocytes of donors fed with recipient splenocytes effect. Male (DBA-2) mice (H-2(d)) as donors were fed with BALB/c splenocytes, DBA-2 splenocytes, bovine serum albumin, or regular chow, every other day. Induction of tolerance was assessed by a mixed lymphocyte reaction (MLR). Female (BALB/c) mice (H-2(d)) as recipients received total body irradiation (TBI) of 6.0 Gy ((60)Cogamma-ray) followed by inoculation of 3 x 10(3) P388 mouse leukemia cells on the same day. Subsequently, tail vein injection of 2 x 10(7) splenocytes supplied by DBA-2 was undertaken. Control groups were fed identically without leukemia cell inoculation. The results showed that GVHD was significantly ameliorated and CD4(+)/CD8(+) ratio increased in recipient-mice transplanted with splenocytes of tolerated donors, compared with control animals. There was no significant difference in survival rate between different groups of recipients inoculated with leukemia cell. It is concluded that the peroral recipient-mouse splenocytes can ameliorate GVHD without hampering effect on GVL.

Influence of intra-bone marrow infusion of peripheral hematopoietic stem cells on graft-versus-host disease / 中国实验血液学杂志

This study was aimed to explore whether the graft-versus-host disease (GVHD) could be alleviated by intra-bone marrow (IBM) infusion of allogeneic hematopoietic stem cells. Female C57BL/6 mice as recipients received total body irradiation (TBI) 4 Gy on day 0, followed by injection of peripheral hematopoietic stem cells (1 x 10(7)) from mobilized male BALB/c with granulocyte-colony stimulating factor (rhG-CSF), and cyclophosphamide (200 mg/kg) was injected intraperitoneally two days later. The results showed that the incidence and severity of GVHD were more low and alleviative in group IBM-PBSCT than that in group TV-PBSCT (p < 0.05). Y chromosome of donor mice could be detected in the bone marrow of recipient mice. It is concluded that the method of intra-bone marrow infusion is superior to injection via the tail vein in the engraftment of hematopoietic stem cells in terms of stem cell homing while the frequency and severity of GVHD in allogeneic mice decrease.

Selective elimination of alloreactive donor lymphocytes by using TBI and cyclophosphamide / 中国实验血液学杂志

This study was aimed to investigate a new method of avoiding graft-vs-host disease (GVHD) through selective elimination of alloreactive donor lymphocytes by using total body irradiation (TBI) and cyclophosphamide (Cy). Female (BALB/c x C57BL/6) F1 mice (H-2(d/b)) as recipients received (60)Co gamma-ray sublethal TBI of 4 Gy on day 0 followed by being inoculated with P388D1 leukemia cell line on day 1, injection of allogeneic splenocytes from C57BL/6 male mice (H-2(b)) was carried out for induction of graft-vs-leukemia (GVL) effect prior to stem cell transplantation (SCT), intraperitoneally injection of cyclophosphamide (Cy) (200 mg/kg) and TBI (9 Gy) was given on day 6. One day later, treated mice were rescued with bone marrow hematopoietic stem cells from (BALB/c x C57BL/6) F1 male mice (H-2(d/b)). The results showed that recipients had no occurrence of leukemia and GVHD through selective elimination of alloreactive donor lymphocytes by Cy and TBI, survived more than 210 days, the complete-donor chimerism occurred on day 21 after transplantation. The ratio of chimerism descended subsequently, but still displayed mixed-chimerism at 90 days. Control mice died of GVHD, leukemia or other death-related-transplantation within 20 to 36 days (P<0.01). It is concluded that to induce GVL effects by MHC mismatched splenocytes given before syngeneic bone marrow transplantation followed by selective elimination of alloreactive donor lymphocytes through TBI and Cy, graft-vs-host disease was thus avoided.

Effects of sensitized donor lymphocyte infusion on the chimerism and graft-versus-host disease after nonmyeloablative allogeneic stem cell transplantation / 中国实验血液学杂志

To explore whether the complete donor chimerism could be achieved and graft-versus-host disease could be alleviated by donor lymphocyte infusion which was sensitized by the skin of the recipient, female C57BL/6 mice (H-2(b), B6) as recipients received total body irradiation (TBI) of 5.5 Gy ((60)Co gamma-ray) on day 0 followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). The allo-grafts consisted of 2 x 10(7) peripheral hematopoietic stem cells from mobilized male BALB/c (H-2(d)) donor mice with the granulocyte colony-stimulating factor (G-CSF). Day 2 after allo-HSCT, the recipient mice were given 200 mg/kg cyclophosphamide intraperitoneally. Afterwards these recipient mice were infused 2 x 10(6) sensitized or unsensitized-donor lymphocytes at the 28 days after transplantation. The results showed that the mice receiving sensitized-donor lymphocyte infusion did not suffer from GVHD and the phenotypic character of the recipient mice (black color) converted to that of the donor mice (white color), and to become full-donor chimerism. It was found that the ratio of CD4(+)/CD8(+) T lymphocytes of them decreased at the earlier period and increased after half month, but which were also lower than that of the normal value. While various grades of acute GVHD was observed in that of the control group and the mixed-chimeras were maintained, though it increased a little, and the ratio of CD4(+)/CD8(+) T lymphocytes increased at first, then decreased to the normal level half month later. It is concluded that sensitized DLI converted mixed to complete donor chimerism without GVHD, and the rate of CD4(+)/CD8(+) has close relation to the incidence of GVHD.

Induction of immune tolerance for allogenic recipient mice by non-myeloablative bone marrow transplantation / 中国实验血液学杂志

This study was aimed to explore the effects and mechanisms of transplantation tolerance induced by "TBI + cyclophosphamide (CTX)" regimen combined with intra-bone marrow injection of allogenic BMCs. On day 0 C57BL/6 (H-2(b), B6) mice received sublethal dose of total body irradiation (TBI) ((60)Co gamma-ray) followed by intrabone marrow-bone marrow transplantation (IBM-BMT) of 3 x 10(7) cells/30 microl BMCs from BALB/c (H-2(d)) mice. The recipient mice were given CTX intraperitoneally 2 days after IBM-BMT. On day 7 skin grafting was performed and the skin survival was observed. The tolerance mechanism was investigated by mixed lymphocyte reaction (MLR), IL-2 reverse test, adoptive transfer assay in vitro. The results showed that the mean survival time (MST) of skin allografts in group treated with TBI + CTX + BMT was significantly longer, compared with that of other groups (P < 0.01). On day 90 after IBM-BMT, the phenotypic character of the recipient mice (black color) began to convert to that of the donor mice (white color). The MLR demonstrated that the immune responses of recipient mice were donor-specific tolerance. Suppressive activity in the spleen cells of tolerant B6 mice was observed in adoptive transfer assay in vitro. IL-2 reversal and the phenotypic conversion showed that the tolerance mechanisms were involved in clonal anergy and the development of chimerism. It is concluded that the nonmyeloablative regimen combined with IBM-BMT can induce a long-term tolerance, and the multiple mechanisms including clonal anergy, suppressor cells and chimerism were involved in transplantation immune tolerance.