Potential interference of agents on radioiodide thyroid uptake in the euthyroid rat.

The objective of this research was to investigate the merits of controlled studies with euthyroid rats as a means of determining the influence of dose and time after administration of agents that may interfere with radioiodide uptake in the thyroid. METHODS: Potassium iodide (KI), propylthiouracil (PTU), diatrizoate meglumine, and iohexol were selected to represent interfering agents. Two dose levels per agent were investigated. Doses used were 1 and 2 mg/kg of body weight for KI, 3.5 and 7 mg/kg of body weight for PTU, 1 mL/kg (282 mg I/kg) and 2 mL/kg (564 mg I/kg) of body weight for diatrizoate meglumine, and 1 mL/kg (300 mg I/kg) and 2 mL/kg (600 mg I/kg) of body weight for iohexol. The 24-h radioiodide thyroid uptake was determined after (131)I was given at 1, 8, 15, and 22 d after administration of interfering agents. RESULTS: The percentage radioiodide uptake value for the thyroid decreased significantly compared with controls for all agents and both doses on day 1 but returned to control levels by day 22 for all agents and both doses The time to return to normal varied between agents and doses. CONCLUSION: We conclude that the interfering agent, the dose given, and the length of time after administration influence the potential for an agent to affect radioiodide uptake in the thyroid. Further studies with the rat, preferably hyperthyroid, would be beneficial in generating data to reduce confusing contradictory information on the length and severity of interference of agents in radioiodide thyroid studies.     

嗜铬细胞瘤患者围手术期处理的改进

目的：探讨提高嗜铬细胞瘤患者围手术期安全性的措施。方法：对15例嗜铬细胞瘤患者、术前采用选择性α1受体阻滞剂多沙唑嗪控释片(可多华)控制高血压；11例患者采用3D DCEMRA进行肿瘤定位；术中均采用联合高容量血液稀释(AHH)和术中患者自体血回输纠正血容量。结果：除1例持续性高血压患者需联合钙离子拮抗剂和ACEI药物降压外．其余患者血压控制均为满意；根据3D DCEMRA定位选择手术径路者均顺利完成手术；AHH联合术中自体血回输使14例患者避免了异体输血。结论：本文围手术期处理改进．可多华可明显减少药物的不良反应；采用3D DCEMRA进行肿瘤定位，可增加手术安全性；AHH联合术中自体血回输可减少医疗成本和异体输血，以及由此而引起的并发症。     

Immunoregulatory effects of phospholipase A2 (PLA2) on the proliferation of human lymphocytes

Extracellular phospholipase A2 (PLA2) is a proinflammatory enzyme found especially in the inflammatory exudate to modulate blood flow to areas of antigen stimulation. In this study we found that PLA2 exerted a biphasic effect on the proliferation of phytohemagglutinin (PHA)-stimulated human mononuclear cells (PHA MNC). At low concentrations range from 0.001 to 1 U/ml, PLA2 enhanced the proliferation of PHA MNC (maximal increase was 37.0 +/- 5.67%). Conversely, at concentrations over 10 U/ml, PLA2 markedly suppressed the PHA-induced MNC proliferation (maximal decrease was 88.86 +/- 2.89%). PLA2 was non-toxic to lymphocytes after three days culture, unless the concentration was higher than 100 U/ml. The membrane polarization of PHA-stimulated lymphocytes was also increased by PLA2 at a low concentration. In addition, PLA2 displayed a similar effect on the proliferation of streptokinase-streptodornase (SK/SD) or allogeneic cell stimulated lymphocytes. The change of lymphocyte proliferation by PLA2, was parallel to the change of percentage of helper T cells. Furthermore--a CD4-rich population was proved more susceptible to PLA2 effect than a CD8-rich population. Para-bromophenacyl bromide (pBPB), an irreversible inhibitor of PLA2, abrogated the biphasic effect of PLA2 on PHA MNC proliferation. These results suggest that PLA2 plays a regulatory role on immune reactions by modulating the percentage of helper T cells.     

Reversible changes in tumor growth and metastatic behavior induced by immune pressure

Prolonged exposure to host immunity was studied for its effect on several characteristics of a cloned 3-methylcholanthrene-induced fibrosarcoma. One million cells of a clone 10-O were injected subcutaneously into normal C3H/HeJ mice (clone 10-N) or tumor-immune mice (clone 10-I). After 10 passages in immune mice, 1 X 10(6) cells from 10-I tumor were transferred back into normal mice (clone 10-R). After 5 to 10 additional in vivo passages, clone 10-O, 10-N, 10-I, and 10-R tumors were transplanted into normal mice and observed for tumor growth rate, tumorigenicity, antigen specificity, metastatic potential, and plating efficiency. Clone 10-I after 10 passages in immunized mice grew significantly more slowly than did 10-O or 10-N clones, required more tumor cells to cause 50% tumor incidence in normal mice (tumorigenicity), and completely lost its capacity to metastasize spontaneously or experimentally. The plating efficiency in vitro of 10-I was also less than that of 10-O or 10-N. All these changes reversed after 5 to 10 passages of 10-I clone back into normal mice (10-R). Although immune pressure induced qualitative antigenic changes, as demonstrated by a tumor-rejection assay, and resulted in no cross-reactivity with control tumor clones (antigen specificity), the degree of immune response to its autologous clone in immune mice (immunogenicity) remained constant. These results suggest that several unrelated characteristics of this clone 10 can be phenotypically changed during the same period by immune pressure.     

Antiarrhythmic effect ofRodiola rosea and its possible mechanism

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 8, pp. 175–176, August, 1993     

Penetration of Schistosoma japonicum cercaria into host skin.

The anterior part of Schistosoma japonicum cercaria is a specialized head organ which can slightly stretch out and retract. There are three different types of large unicellular glands in cercarial body, consisting of one head gland, 2 pairs of pre- and 3 pairs of postacetabular glands. These glands differ in position, gross feature, histochemistry and functions. Both polysaccharase and protease activities are demonstrated in the secretions from these glands. Mode of cercarial penetration is described in detail and the penetration is effected by a combination of lytic secretions and mechanical movements. The schematic representation of the process of cercarial penetration is presented. The dynamic distributions of schistosomula in skin at different time intervals after skin penetration in various mammalian hosts are shown. Some newly transformed schistosomula die while penetrating into the skin of 7 mammalian species and the mortality rate varies with the host species, and that can also be affected by the age of cercariae following emergence from the snail. Some physiological aspects between cercariae and newly transformed schistosomula are compared. In contrast to cercariae, schistosomula are saline-adapted and water-intolerant. They were modified histochemically and antigenically.