NOD鼠胸腺及外周淋巴细胞亚群变化与年龄关系

ＮＯＤ鼠可自发地患糖尿病，该鼠的发病与自身免疫性淋巴细胞对胰岛的浸润，从而引起胰岛β细胞的不断破坏有关。这种破坏可能是由Ｔ淋巴细胞所引起的。雌性ＮＯＤ鼠胸腺及外周淋巴细胞随年龄的增加胸腺细胞数量减少而脾细胞数量增加。用ＣＤ４／ＣＤ８双抗双标检测显示，雌性ＮＯＤ糖尿病鼠胸腺双阴性与单阳性细胞的比例增加而双阳性细胞的比例减少。外周ＣＤ４比ＣＤ８阳性细胞的比值在胰岛炎期增高，在糖尿病期下降。     

Shielding Effect of Mineral Schungite during Electromagnetic Irradiation of Rats

We studied the effect of nonthermal 37-GHz radiation on hemopoiesis in schungite-shielded Wistar rats. Radiation with right-handed or left-handed rotation of the polarization plane of electromagnetic wave was used. Shielding with schungite decreased the severity of damage produced by high-frequency electromagnetic radiation.     

Lymphocyte proliferation in response to acute heavy resistance exercise in women: influence of muscle strength and total work

Little is understood about the immune responses to heavy resistance exercise. The purpose of this investigation was to determine the influence of physical strength and the ability to do more total work on lymphocyte proliferation after an acute bout of heavy resistance exercise. A group of 50 healthy but non-strength trained women were recruited for the study and tested for their one repetition maximum (i.e. 1 RM or maximal mass lifted once). From the normal distribution of strength the top and bottom 8 women [mean age 22.5 (SD 3.1) years] were asked to volunteer to define our two groups (i.e. high strength and low strength). The two groups were significantly different (P<0.05) in 1 RM squat strength [low strength 39.9 (SD 4.6) kg, 0.65 (SD 0.08) kg·kg body mass^–1 and high strength 72.2 (SD 10.7) kg, 1.1 (SD 0.12) kg·kg body mass^–1] but were not significantly different in body mass, age, activity levels, and menstrual status (all in same phase). Each performed a resistance exercise protocol consisting of six sets of 10 RM squats with 2 min rest between the sets. The 10 RM loads and total work were significantly greater in the high strength group than in the low strength group. Blood samples were obtained pre-exercise and immediately post-exercise for test for lactate (significant increase with exercise) and cortisol (no changes) concentrations with no differences noted between groups. Immunological assays on the blood samples determined the incorporation of tritiated thymidine by lymphocytes in responses to concanavalin A (ConA), phytohemagglutinin (PHA), and pokeweed mitogen (PWM). Following the squat exercise, there was a significant decrease in lymphocyte responsiveness to PWM in the high strength but not in the low strength group for both total proliferation and proliferation adjusted per B or T cell. On the other hand, lymphocytes from the low strength group proliferated to a significantly greater extent (adjusted per T cell) in response to ConA and PHA. These data indicate that the heavy resistance exercise protocol reduced the lymphocyte proliferative responses only in the stronger group of subjects. This effect may have been due to the high absolute total work and the greater exercise stress created by the resistance exercise protocol in the high strength group. Therefore, individuals performing at the same relative exercise intensity (i.e. 10 RM) in a resistance exercise protocol may have different immune responses stemming from differences in absolute total work performance. Electronic Publication     

Hemoglobin levels in Tibet: different effect of age and gender for Tibetans vs Han

Tibetans form a population which has resided on the Qinghai–Tibetan plateau for thousands of years, and are reported to have less hemoglobin than Han Chinese lowlanders who have migrated to the plateau. However, for various altitudes, detailed comparisons of hemoglobin in the two ethnic groups has not been reported. We investigated the hypothesis that the effects of altitude, age, and gender on hemoglobin concentration would differ between Han and Tibetan residents of the plateau. Hematological parameters for both genders were determined in healthy Tibetan adults (n=3,000) and children (n=332), and healthy Han Chinese adults (n=2,612) and children (n=275), aged 5–60 years living at four different altitudes (mean altitude of 2,664, 3,813, 4,525, and 5,200 m). Hemoglobin values increased with altitude for all ages in both ethnic groups and in both genders. The gain in hemoglobin with altitude had the rank order: Han males > Han females > Tibetan males and females. Even before puberty, Han children had more hemoglobin than Tibetan children. An effect of age on hemoglobin was seen at the time of puberty in men, but not in women. A positive correlation was found between hemoglobin concentration and age in adult Han males and females, but not in Tibetan males, and only at the higher altitudes, in Tibetan females. In both Tibetans and Hans, males had higher hemoglobin values than females at each altitude, but the gender differences increased with altitude in Han, whereas it either decreased or did not change in Tibetans. Examination of hemoglobin levels by histogram showed non-Gaussian distributions: Tibetan men and women had skewing to higher values, whereas Han men and women had skewing in the opposite direction. We conclude that increasing age and the effect of gender in Tibetans are associated with different hemoglobin responses to altitude than in Han, and we speculate that genetic influences may be involved.     

Total lymphocyte count of 1200 is not a sensitive predictor of CD4 lymphocyte count among patients with HIV disease in Kampala, Uganda

Introduction

Total Lymphocyte Count (TLC) has been found to be an inexpensive and useful marker for staging disease, predicting progression to AIDS and death and monitoring response to ART. However, the correlation between TLC and CD4 has not been consistent. Access to HAART is expanding in Kampala, Uganda, yet there are no published data evaluating the utility of TLC as inexpensive surrogate marker of CD4 cell count to help guide therapeutic decisions.

Objective

To evaluate clinical illnesses and total lymphocyte count (TLC) as surrogate markers of the CD4 cell count in HIV infected persons being considered for ART.

Methods

A total of 131 patients were enrolled and evaluated by clinical assessment, TLC and CD4 count. Clinical illnesses and TLC dichotomized at various cut-point values were used to determine the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for the diagnosis of CD4 count <200 cells/mm³ among 100 participants fulfilling criteria for WHO clinical stage 2 and 3.

Results

A strong correlation was observed between TLC and CD4 (r = 0.73, p<0.0001). For all clinical syndromes, except pulmonary tuberculosis, the positive predictive values (PPV) for a CD4 count <200 cells/mm³ were high (>80%) but the negative predictive values (NPV) were low. Using the WHO recommended TLC cut-off of 1200 cells/mm³ to diagnose a CD4 less than 200 cells/mm³, the PPV was 100%, and the NPV was 32%.

Conclusion

Our data showed a good correlation between TLC and CD4 cell count. However, the WHO recommended TLC cutoff of 1200 did not identify the majority of WHO stage 2 and 3 patients with CD4 counts less than 200 cells/mm³. A more rational use of TLC counts is to treat all patients with WHO stage 2 and 3 who have a TLC <1200 and to limit CD4 counts to patients who are symptomatic but have TLC of >1200.     

Lymphocyte Subsets and Mitogen Stimulation of Blood Lymphocytes in Normal Pregnancy

PROBLEM: In normal pregnancy the maternal immune system should be directed towards tolerance or suppression in order not to reject the partly foreign feto-placental unit. The aim of this investigation was to find hallmarks of systemic immunosuppression during normal pregnancy. METHODS: Five healthy primigravidae were examined during pregnancy and postpartum with flow cytometric analysis to define T and B lymphocyte subsets in peripheral blood. In addition, we studied the proliferative response of lymphocytes to mitogens or interleu-kin-2 (IL-2) alone or in combination with immunomodulating drugs or interleukin-4 (IL-4). The results were compared to healthy, non-pregnant women. RESULTS: During pregnancy and early puerperium we noted an immune balance in favour of suppression, as measured by increased numbers of T “helper/suppressor” (CD4+ CD45RA+) and “suppressor”/effector T cells (CD8+S6F1-), and decreased numbers of T “helper/inducer” (CD4+CD29+), T “helper/memory” (CD4+CD45RO+), killer/effector T cells (CD8+S6F1+), and Natural Killer cells (CD56+), as well as decreased numbers of activated lymphocytes expressing IL-2 receptor (CD25+) and T cells expressing HLA-DR (HLA-DR+CD3+). During pregnancy, lymphocyte proliferation was impaired in autologous serum with concanavalin A (ConA), phytohemagglutinin (PHA), or IL-2. A difference in proliferative response to PHA or IL-2 between cultures with AB serum and autologous serum is suggestive of an immunosuppressor factor in serum during pregnancy. Indomethacin significantly increased lymphocyte proliferation in autologous serum with ConA, indicating PGE₂ mediated suppressor activity during pregnancy. Chlorambucil and cimetidine modulated the proliferative response to ConA, indicating an alkylating agent sensitive and a histamine dependent suppressor activity during pregnancy. CONCLUSIONS: During normal pregnancy, a state of systemic suppression of the maternal immune system seems to be present.     

地塞米松对儿童自身免疫病患者外周血淋巴细胞早期凋亡的影响

目的　为了观察儿童自身免疫病患者 (以SLE为代表 )在应用地塞米松 2 4h前后细胞凋亡情况 ,对其外周血淋巴细胞早期凋亡率进行了检测。方法　应用最新的AnnexinV检测试剂盒及流式细胞仪检测早期凋亡细胞。结果　儿童SLE初发活动期患者外周血淋巴细胞早期凋亡率 (2 .36 6± 1.5 34% )明显低于经静脉注射地塞米松 2 4h后的患儿 (10 .6 96±2 .830 % )及同年龄段正常儿童 (12 .4 95± 2 .4 78% ) ;而后两者相比则无明显差异。结论　儿童SLE活动期患者经过静脉注射地塞米松以后 ,外周血淋巴细胞凋亡率明显升高。其可能的机制为固醇类激素通过激活促进凋亡基因 ,从而促进大量淋巴细胞凋亡 ,使自身免疫病的发生受到控制。     

Thrombocytosis in preterm infants: a possible involvement of thrombopoietin receptor gene expression

Transient thrombocytosis is commonly observed in preterm infants after birth, but its physiological mechanism is still unknown. To understand the mechanism of the transient thrombocytosis in preterm infants we firstly evaluated a correlation between platelet counts and thrombopoietin (TPO) levels in preterm infants and next c-mpl mRNA levels on platelets in healthy preterm infants longitudinally during a half-year of life. The mean platelet counts in 45 very low birth weight infants (mean gestational age 27.4±1.8 weeks, mean birth weight 1047±249 g) was 230±71×10⁹/l just after birth and thereafter gradually increased to 579±178×10⁹/l by 5 weeks of age. The platelet counts continued this level for about next 8 weeks. Serum TPO levels soon after birth and at 1 month of age were significantly higher than those at the age of 2–6 months. There was a significant negative correlation between platelet counts and serum TPO values. The c-mpl expression levels on platelets at birth and at 1 month of age tended to be lower than those on platelets from adults, and the c-mpl levels gradually increased through 6 months of age, although they were still lower than those of adults. Our results suggest that low expression of TPO receptor on platelets until 1 month after birth cause a decreased TPO clearance and keep a high level of free TPO in blood, thereby promoting platelet production from megakaryocytes or their progenitors in bone marrow, resulting in the subsequent thrombocytosis in preterm infants.     

Rapid accurate absolute granulocyte count determination during severe leukopenia using the flow cytometer

The absolute granulocyte count (AGC) in 125 blood samples from patients with total white blood cell counts of less than 1,000/microliter was estimated using three different methods, which were then compared for efficiency and accuracy. The three methods were 25 cell differential counts using Wright's-stained blood smears, granulocyte percentage estimates from WBC counting chambers, and combined narrow- and wide-angle light-scatter characteristics determined on a flow cytometer. A survey of clinical laboratories at University Hospital Cancer Centers revealed that the smear differential was the most-often-used method in those laboratories even when less than 25 cells could be counted. Consequently the data obtained from the counting chamber and flow cytometer methods were compared to the smear differential "standard" using linear regression, and outliers were identified. There was good correlation between AGC determined by smear differential and WBC counting chamber (correlation coefficient .911) and excellent correlation between the AGC determined by smear differential and the flow cytometer method (correlation coefficient .970). The flow cytometer method used in this investigation required minimal specimen preparation, and test results were available at a rate of 60 seconds/sample. The ease of sample preparation, speed, and statistical reliability of test results makes the flow cytometer an attractive alternate method of determining granulocyte counts on leukopenic patients as compared to the stained blood smear differential.