Divergent cytokine production profile in Behçet's disease. Altered Th1/Th2 cell cytokine pattern

OBJECTIVE

To determine Th1/Th2 cell response cytokine production profile in Behçet's disease (BD).

METHODS

Interleukin 2 (IL-2), interferon-gamma (IFN-gamma) and IL-12 (Th1 cell response), and IL-4, IL-10, and IL-13 (Th2 cell response) cytokine production from anti-CD3/anti-CD40 stimulated peripheral blood mononuclear cells (PBMC) were measured by ELISA.

RESULTS

PBMC from patients with BD produced higher levels of IL-4, IL-10, and IL-13 (Th2 cell response), almost normal levels of IL-2 (Th1 cell response), but highly deficient IFN-gamma and IL-12 (Th1 cell response). The additions of exogenous recombinant IFN-gamma to the anti-CD3 stimulated PBMC dramatically changed this pattern with enhanced IL-12 and concomitantly decreased IL-4 and IL-10 production.

CONCLUSION

The immune system in BD may be characterized by a divergent cytokine production profile of mixed Th1/Th2 (Th0) cell type; IFN-gamma is critical in modulating the IL-4, IL-10, and IL-12 cytokine network pathway in this disease.

Prostanoid production in the umbilicoplacental arterial tree relative to impaired glucose tolerance

The purpose of this study was to investigate prostanoid synthesis in different segments of the umbilicoplacental vascular tree and its relationship to impaired maternal glucose tolerance. Segments from the umbilical artery and vein, allantochorionic artery branches, and the cotyledon artery from 21 women with diabetes or impaired glucose tolerance and 10 healthy women were studied. Production of prostacyclin (PGI2) and thromboxane (TxA2) metabolites was determined. The Mann-Whitney U test, Wilcoxon signed-ranks matched-pairs test, Kruskal-Wallis test, analysis of variance, and simple linear regression analysis were used. A two-tailed P value of < 0.05 was considered statistically significant. From the umbilical artery distal to the cotyledon artery, the PGI2 synthesis decreased and the TxA2 synthesis increased gradually towards the periphery in normal pregnancy. The PGI2/TxA2 ratio was more than 200 times higher in the umbilical artery than in the cotyledon artery. The TxA2 production tended in general to be higher in the diabetic group than in the control group, resulting in significantly lower PGI2/TxA2 ratios in some vessels. The prostanoid production was not significantly correlated to maternal HbA1c or cord C-peptide concentrations. The balance between vascular prostacyclin and thromboxane synthesis in the umbilicoplacental arterial tree changed gradually towards the periphery: the more peripheral, the lower the prostacyclin and the higher the thromboxane production. The physiological role of this phenomenon is unknown, but may be of importance for the equilibration of vascular tone between arteries of different calibers. The altered prostanoid balance found in diabetic pregnancy was not directly attributable to the degree of maternal glycemic control, but may reflect increased free radical activity and peroxide production in diabetes.

Activation of naive xenogeneic but not allogeneic endothelial cells by human naive neutrophils: a potential occult barrier to xenotransplantation

Here we demonstrate that human neutrophils, the predominant circulating leukocytes in intimate contact with endothelial cells lining the vasculature, directly recognize xenogeneic endothelium independently of xenoreactive natural antibody and complement. A rapid and calcium-dependent activation of native (unstimulated) xenogenic endothelial cells by human neutrophils leads to 1) translocation of P-selectin from the Wiebel-Palade bodies to the surface of xenogeneic endothelial cells, 2) increased synthesis and expression of vascular cell adhesion molecule-1 on the xenogeneic endothelial cells, and 3) enhanced killing of the xenogeneic endothelium by natural killer cells. Our data directly implicate naive neutrophils as major early participants in xenograft recognition and endothelial activation independent of xenoreactive natural antibodies and complement.

Activation of coagulation and fibrinolysis in heatstroke

Hemorrhagic diathesis and widespread microthrombosis are common in heatstroke. To assess the early stages of coagulopathy in heatstroke, thrombin-antithrombin III (TAT), fibrin monomers, plasmin-alpha 2-antiplasmin (PAP), plasminogen and D-Dimer were measured in 16 heatstroke patients (means +/- SE rectal temperature 42.3 +/- 0.2 degrees C) pre- and postcooling and compared with 8 heatstressed and 23 normal controls. Comparing heatstroke patients with normal controls, TAT, fibrin monomers, PAP and D-Dimer were elevated to (median (range)) 16.5 (4-1000) versus 3.5 (2-7.2) micrograms/l p < 0.001, 16 (4-113) versus 2 (2-9) nM p < 0.001; 3300 (1000-36500) versus 255 (136-462) micrograms/l p < 0.001 and 0.72 (0.22-64.8) versus 0.15 (0.05-0.25) microgram/ml p < 0.01 respectively. Plasminogen decreased to 81% (34-106); PAP, TAT and D-Dimer correlated significantly with hyperthermia (r = 0.577, p = 0.02; r = 0.635, p = 0.01; r = 0.76, p = 0.003). Postcooling PAP decreased to 545 (260-850) micrograms/l p < 0.005, TAT 10 (6-70) micrograms/l, and fibrin monomers 22 (18-86) nM remained unchanged. Heatstressed controls showed mild but significant increase in all markers. Activation of coagulation and fibrinolysis occurs early and is profound and sustained in heatstroke. Cooling seems to attenuate the activation of fibrinolysis only, however, this requires confirmation in a larger study population.

Prostanoid production in umbilical vessels and its relation to glucose tolerance and umbilical artery flow resistance

OBJECTIVE

To study prostanoid synthesis in umbilical vessels relative to maternal glucose tolerance and umbilical artery blood flow resistance.

STUDY DESIGN

Umbilical artery pulsatility index was determined by Doppler velocimetry in 21 women with diabetes or impaired glucose tolerance and 10 healthy women. Segments from the umbilical artery and vein were incubated and prostacyclin (PGI2) and thromboxane (TxA2) metabolites determined. Statistical analyses with the Mann-Whitney U test, Kruskal-Wallis test, Wilcoxon signed-ranks matched-pairs test, contingency table analysis, Fisher's exact test, and simple linear regression analysis were used and a two-tailed P value of < 0.05 considered statistically significant.

RESULTS

No significant difference in PGI2 or TxA2 production was found in umbilical vessels between the women with diabetes/impaired glucose tolerance and controls, but the PGI2/TxA2 ratio in the vein was significantly lower in the diabetes/impaired glucose tolerance group. The umbilical artery pulsatility index was positively correlated to the PGI2/TxA2 ratio in cord vessel segments and to cord plasma TxA2 concentration. The cord plasma TxA2 concentration was significantly higher in cases with a high umbilical artery pulsatility index. The prostanoid production was not correlated to maternal HbA1c or cord plasma C-peptide concentrations.

CONCLUSIONS

In association with diabetes, an increased 'peroxide vascular tone' and an enhanced 'endoperoxide shift' between platelets and vascular endothelium may explain the unexpected positive correlation found between the umbilical artery pulsatility index and the vascular PGI2/TxA2 synthesis ratio.

Evidence for endothelial cell activation/injury in heatstroke

OBJECTIVES

We treated the hypothesis that heatstroke is associated with endothelial cell activation/injury and examined the possibility that the markers of endothelial cell activation/injury may be associated with its severity and complications such as disseminated intravascular coagulation, lung injury, and renal dysfunction.

DESIGN

Prospective analyses.

SETTING

Heatstroke Center in Makkah, Saudi Arabia.

PATIENTS

Twenty-two adult patients with heatstroke.

INTERVENTIONS

The plasma concentration of endothelin, circulating intercellular adhesion molecule-1 (ICAM-1), and von Willebrand factor-antigen values were measured, respectively, by radioimmunoassay, enzyme-linked immunosorbent assay, and rocket electroimmunoassay, in heatstroke patients on admission (precooling) and after complete cooling (postcooling), and in ten normal control patients.

MEASUREMENTS AND MAIN RESULTS

Precooling heatstroke patients (rectal temperature 40.9 +/- 1.1 [SD] degrees C) had increased circulating concentrations of endothelin, c-ICAM-1, and von Willebrand factor-antigen in 100%, 80%, and 77% of patients to 126.4 +/- 11.2 pmol/L, 523.1 +/- 154.4 ng/mL, and 3.85 +/- 2.3 U/mL, respectively (control values: 13.7 +/- 4.2 pmol/L [p < .001]; 247.4 +/- 68.2 ng/ml [p < .001]; and < 1.5 U/mL, respectively). There was a significant (r2 = .68, p < .01) correlation between circulating ICAM-1 and endothelin concentrations. Plasma endothelin concentration correlated negatively with temperature (r2 = .35, p < .05). Mean endothelin concentration was similar in patients with or without renal dysfunction, and mean von Willebrand factor-antigen concentration was similar in patients with or without lung injury or disseminated intravascular coagulation. There were no significant correlations between circulating ICAM-1, endothelin, or von Willebrand factor-antigen concentration and the Simplified Acute Physiology core. After cooling, mean circulating ICAM-1 and endothelin concentrations decreased significantly to 400 +/- 109 ng/mL and 93 +/- 38.5 pmol/L, respectively, whereas the mean von Willebrand factor-antigen concentration increased to 5.55 +/- 2.18 U/mL (p > .05).

CONCLUSIONS

Our findings of increased circulating concentrations of circulating ICAM-1, endothelin, and von Willebrand factor-antigen are consistent with the hypothesis that heatstroke is associated with endothelial cell activation/injury. Whether the endothelial cell activation/injury is implicated in the pathophysiology of this disorder merits further studies.

The expression of the MDM2 gene, a p53 binding protein, in thyroid carcinogenesis

BACKGROUND

The authors previously found p53 mutations in 24% of malignant thyroid tumors, representing a wide stating spectrum. Overexpression of MDM2, most often due to gene amplification, has been suggested to be an additional mechanism for abrogation of the p53 function. In the current study, MDM2 gene expression and amplification were examined in a randomly selected subset of these tumors to explore the possibility that wild-type p53 may be inactivated by complexing with MDM2 in specimens without p53 mutations.

METHODS

MDM2 gene expression and amplification were studied by Northern and Southern blot analysis, respectively. Twenty-two thyroid tumors were included: 16 papillary carcinomas, 1 follicular carcinoma, 3 anaplastic carcinomas, and 2 multinodular goiters (adenomatous goiters).

RESULTS

A two- to threefold increase in MDM2 expression in 4 of 20 thyroid carcinomas was found. It was noteworthy that all of these four samples harbored p53 mutations. The association between increased MDM2 expression and p53 mutation was statistically significant (P < 0.005). No evidence of MDM2 gene amplification or rearrangement accounting for such an increase in MDM2 expression was found.

CONCLUSIONS

Genetic and/or environmental factors contributing to random p53 mutations also may cause increased MDM2 expression. Given the moderate increase in MDM2 expression without associated genetic alterations such as gene amplification and rearrangement, MDM2 may not play any significant role in the development and progression of thyroid carcinoma.

Enhanced interleukin 8 secretion in circulation of patients with Behçet's disease

OBJECTIVE

The pathogenesis of Behçet's disease (BD) has not yet been determined. Several hypotheses have been postulated and cytokines that control growth proliferation and hematopoiesis of progenitor cells play a role in relation to immune response and inflammatory dysfunction. We investigated whether cytokines play a role in pathogenesis of BD.

METHODS

We employed the quantitative sandwich enzyme immunoassay technique, in which antibody is already coated on the microtiter plate standard and samples are pipetted into the wells. Antigen present is bound by immobilized antibody. After incubation and washing steps, conjugate, which is enzyme linked polyclonal antibody specific for the antigen is added to the wells. Following a wash to remove any unbound antibody enzyme reagent, a substrate solution is added to the wells, and color develops in proportion to the antigen bound in the initial steps, which can be read in terms of optical density present in the standards and in the samples.

RESULTS

Of a total of 53 samples with BD, 33 (64%) had detectable levels of interleukin 8 (IL-8). Levels of IL-6, tumor necrosis factor alpha and interferon-gamma were not significantly elevated in patients with BD.

CONCLUSION

We found that IL-8 levels are higher in patients with active BD, and since IL-8 has a potent effect on the neutrophil, this cytokine most likely participates in the inflammatory response of this disease.

Post-irradiation DNA synthesis inhibition and G2 phase delay in radiosensitive body cells from non-Hodgkin's lymphoma patients: an indication of cell cycle defects

In the present study, both post-irradiation DNA synthesis and G2 phase accumulation were analyzed in lymphoblastoid cell lines (LCLs) and fibroblast cell strains derived from (Saudi) patients with non-Hodgkin's lymphoma (NHL), ataxia telangiectasia (AT), AT heterozygotes and normal subjects. A comparison of the percent DNA synthesis inhibition (assayed by 3H-thymidine uptake 30 min after irradiation), and a 24 h post-irradiation G2 phase accumulation determined by flow cytometry placed the AT heterozygotes and the NHL patients in an intermediate position between the normal subjects (with maximum DNA synthesis inhibition and minimum G2 phase accumulation) and the AT homozygotes (with minimum DNA synthesis inhibition and maximum G2 accumulation). The similarity between AT heterozygotes and the NHL patients with respect to the two parameters studied after irradiation was statistically significant. The data indicating a moderate abnormality in the control of cell cycle progression after irradiation in the LCLs and fibroblasts from NHL patients may explain the enhanced cellular and chromosomal radiosensitivity in these patients reported by us earlier. In addition to demonstrating a link between cell cycle abnormality and radiosensitivity as a possible basis for cancer susceptibility, particularly in the NHL patients, the present studies emphasized the usefulness of the assay for 24 h post-irradiation G2 phase accumulation developed by Lavin et al. (1992) in characterizing AT heterozygote-like cell cycle anomaly in cancer patients irrespective of whether they carried the AT gene or any other affecting the cell cycle.

Reduced induction of P53 protein by gamma-irradiation in ataxia telangiectasia cells without constitutional mutations in exons 5, 6, 7, and 8 of the p53 gene

Ataxia telangiectasia (AT) is an autosomal recessive disease of childhood with several phenotypic characteristics. One of the hallmarks of this syndrome is its hypersensitivity to ionizing radiation, which is believed to be due to defects in DNA repair/processing. In addition to radio-resistant DNA synthesis, both fibroblasts and lymphoblastoid cell lines derived from these patients have been shown to have an impaired G1 arrest and prolonged G2 accumulation of cells indicating a defect in the regulation of cell cycle after irradiation. Since the (tumor suppressor) p53 protein has been reported to participate in the regulation of G1 arrest after irradiation, the possibility of p53 gene mutation and deregulating cell cycle in AT needed to be examined. We used the PCR amplification and DNA sequencing methods to detect mutations in the hypermutable exons (5-8) of germline p53 in fibroblast cells from 3 AT homozygotes. No mutation was found in any of these exons. In order to determine the role of the p53 protein in G1 arrest, its levels were measured before and after gamma-irradiation by flow cytometry in both AT and normal cells. Radiation-induced p53 protein levels in the AT cells varied from 6 to 60% compared to the normal cells, indicating a reduced induction of the protein in AT. These results suggest that mutation in the AT gene affects the p53 induction by irradiation and may, thus, alter the cell cycle regulation in the AT patients.

Differential nm23 gene expression at the fetal-maternal interface

The product of the nm23 gene has been proposed as a candidate tumour metastasis suppressor protein. A strong association has been observed between reduced expression of the nm23 gene and acquisition of metastatic behaviour in some tumour cells, including breast cancer and melanoma, but not in others, such as neuroblastoma and colon, cervical and thyroid cancers. During the early gestation period both human and murine trophoblast cells exhibit in vitro invasive properties similar to those of neoplastic cells. Such invasive properties, however, disappear in the late stage of gestation. In the present study, we examined the abundance of nm23 mRNA from various fetal-maternal interface tissues (uterus, decidua, placenta and embryo) during early (day 8), mid (day 14) and late (day 18) stages of gestation in CD1 mice, in order to determine whether nm23 plays any anti-invasive and/or biological roles during gestation. nm23 was found to be expressed in all the tissues during the early and mid stages of gestation. The expression levels were, however, variable among different tissues and development stages. In the early stage, nm23 mRNA levels were the highest and similar among tissues from the uterus, decidua, placenta and embryo. In the mid stage, the mRNA levels were reduced significantly in the uterus, decidua and placenta, but not in the embryo. In the late stage, nm23 mRNA was further reduced to the extent that it could not be seen in the decidua, was barely seen in the uterus and was weakly present in the placenta. However, the mRNA level of the embryo in the late stage was still high and similar to the early stage. We also examined nm23 expression in trophoblast cells from normal human term placenta and a highly metastatic human choriocarcinoma cell line, JAR. nm23 expression was significantly higher in JAR than in normal placenta, indicating that nm23 does not appear to have an anti-metastatic function in this cell line. Several cytokines--interleukin 2 (IL-2), tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma)--and prostaglandin E2 (PGE2) known to modulate tumour growth and metastasis were examined to determine whether they regulate nm23 expression in JAR in vitro. The B16F10 melanoma cell line was used as control. No effect was found in the JAR cell line, whereas TNF-alpha, IFN-gamma and PGE2 down-regulated nm23 expression in the B16F10 cell line.(ABSTRACT TRUNCATED AT 400 WORDS)

A molecular study of EBV DNA and p53 mutations in nasopharyngeal carcinoma of Saudi Arab patients

Tumor biopsies obtained from 25 Saudi Arab patients with nasopharyngeal carcinoma (NPC) were examined for the presence of Epstein-Barr virus (EBV) DNA detected by the polymerase chain reaction (PCR) and for the incidence of p53 mutations screened by a combination of PCR, single strand conformation polymorphism (SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP). DNA sequencing was carried out to confirm the occurrence of p53 mutation. While 92% of the tumor specimens were found to carry EBV DNA, only 1/25 showed the incidence of a homozygous mutation at codon 248 of the p53 gene. The data showed that despite a high association of EBV infection with Saudi NPC, the frequency of p53 mutations was very low. Our results are consistent with the worldwide observation of infrequent p53 mutations in NPC.

Inhibition of neutrophil functions by human immunoglobulin E

Incubation of human neutrophils with human immunoglobulin (Ig) E caused dose-dependent inhibition of adhesion, phagocytosis, secretion of myeloperoxidase, and oxygen radical production. The concentrations of IgE that caused 50% inhibition of adhesion, phagocytosis, and secretion were 2 +/- 0.3, 2.16 +/- 0.21, and 1.95 +/- 0.28 ng/ml, respectively. Oxidase activation as measured by luminol-dependent chemiluminescence by the receptor-mediated N-formyl-methionyl-leucyl-phenylalanine, phorbol 12-myristate 13-acetate, or the particulate stimulus Staphylococcus aureus was inhibited by IgE with concentrations causing 50% effect of 1.2 +/- 0.13, 1.09 +/- 0.16, and 0.6 +/- 0.09 ng/ml, respectively. IgE also inhibited oxygen consumption rate and cytochrome c reduction with similar K0.5 values. The effect of IgE was unlikely to be due to nonspecific cytotoxicity because trypan blue exclusion test and the cytoplasmic marker lactate dehydrogenase revealed that the cells retained their viability after IgE treatment. Similar or higher concentrations of IgG invoked either no inhibition or a slight enhancement of neutrophil functions. Pretreatment of neutrophils with IgG failed to affect the IgE-induced inhibition. Because the effect of IgE occurs at concentrations less than those reported in hyperimmunoglobulinemia E, we propose that direct inhibition of neutrophil functions may underlie the pathogenesis of recurrent infection associated with hyperimmunoglobulinemia E.

Elevated pyrogenic cytokines in heatstroke

STUDY OBJECTIVES

Heatstroke, characterized by hyperthermia and neurologic abnormalities, can cause shock, adult respiratory distress syndrome, and multiorgan failure culminating in death. The mediation of metabolic changes and tissue damage is not fully understood. Recent evidence suggests the involvement of endotoxin, tumor necrosis factor alpha (TNF-alpha), and interleukin 1 alpha (IL-1 alpha) and we hypothesized that other pyrogenic cytokines may be implicated.

DESIGN

Prospective analysis.

SETTING

Heatstroke Center in Makkah (Mecca), Saudi Arabia.

MEASUREMENTS AND RESULTS

We measured plasma IL-1 beta, IL-6, and interferon gamma (INF-gamma) concentrations by enzyme-linked immunosorbent assay in 28 heatstroke patients at the time of hospital admission (precooling) and after complete cooling (postcooling), and in 10 normal control subjects. We measured C-reactive protein (CRP) as a marker of acute phase response and calculated severity of illness using the simplified acute physiology score. Twenty-five male and 3 female subjects had mean (+/- SEM) rectal temperature of 41.2 +/- 0.2 degrees C. IL-6, IL-1 beta, and INF-gamma concentrations were elevated in 100 percent, 39 percent, and 50 percent of patients to (mean +/- SEM) 220 +/- 44 pg/ml, 42 +/- 14 pg/ml, and 1,180 +/- 879 pg/ml, respectively (normal control values: < 3.5 pg/ml, < 4.5 pg/ml, < 20 pg/ml). The CRP value was elevated in 72 percent of patients to 152 +/- 40 mg/L (control value: 0 to 17 mg/L). The IL-6 concentrations correlated with severity of illness (r = 0.516, p = 0.03); two patients with the highest concentrations died. There was no significant correlation between circulating levels of IL-6, IL-1 beta, INF-gamma, and temperature, or between IL-6, IL-1 beta, and CRP. Postcooling, IL-6, and IL-1 beta were still above normal control values; INF-gamma could be detected in one patient only.

CONCLUSION

Our findings of elevated circulating IL-6, IL-1 beta, and INF-gamma in the presence of acute phase response, and correlation with severity of illness, suggest that these cytokines have a role in the pathogenesis of heatstroke, which could lead to new therapeutic strategies.

Effectiveness of four intravenous IgG preparations in prevention of phagocytosis of anti-Rh-(D)-coated erythrocytes by mononuclear phagocytes

Four commercial intravenous immunoglobulin G (IGIV) preparations, Sandoglobulin (Sandoz), Intraglobin (Biotest), Gammonativ (Kabivitrum) and Gammaogard (Kabivitrum) showed percent inhibition of Fc receptor-mediated phagocytosis of anti-Rh(D)-coated erythrocytes as follows: 45 +/- 14 SD, 41 +/- 23 SD, 35 +/- 14 SD, 25 +/- 13 SD, respectively. Pre-incubation of Rh(D)-positive and antibody-coated Rh(D)-positive erythrocytes with IGIV did not lead to any inhibitory effects on phagocytosis. However, preincubation of mononuclear phagocytes with IGIV gave marked inhibition of phagocytosis of antibody-coated erythrocytes. In summary, all four IGIV preparations showed Fc receptor-mediated inhibition of phagocytosis of anti-Rh(D)-coated erythrocytes by mononuclear phagocytes.

High levels of Nm23 gene expression in advanced stage of thyroid carcinomas

The product of Nm23 gene has been proposed as a candidate tumour metastasis suppressor protein. A strong association has been observed between reduced expression of Nm23 gene and acquisition of metastatic behaviour in some tumour cells including breast cancer and melanoma, but not in others such as colon cancer, neuroblastoma, and cervical cancer. In the present study, we examined the abundance of Nm23 mRNA in 39 thyroid tissue specimens including five multinodular goitres, one follicular adenoma, 26 papillary and three follicular carcinomas, and four anaplastic carcinomas. Nm23 was found to be expressed in all the tissue specimens. The expression was, however, variable in different stages of thyroid carcinoma. In stages I through III of differentiated thyroid carcinoma, the average level of Nm23 gene expression was comparable to that in multinodular goitres. In advanced stage of thyroid carcinoma (stage IV and anaplastic), 2-fold increase of Nm23 expression was noted. No mutations were found in the coding region of the gene. Nm23 mRNA level cannot, therefore, be used as a marker of low metastatic potential in thyroid carcinomas. The association of high level Nm23 expression with anaplastic thyroid carcinoma suggests its correlation with rapid cell proliferation.

Alteration of taurine homeostasis in acute heatstroke

OBJECTIVE

To investigate the potential role of taurine as a hypothermic modulator during heatstroke.

DESIGN

Prospective analyses.

SETTING

Heatstroke Center in makkah, Saudi Arabia.

PATIENTS

Twenty-nine adult patients with heatstroke.

INTERVENTIONS

High-performance liquid chromatography was used to measure plasma and urine taurine concentrations in heatstroke patients on admission (precooling) and 24 hrs after complete cooling (postcooling).

MEASUREMENTS AND MAIN RESULTS

There were 18 males and 11 females with a mean rectal temperature of 42.2 +/- 0.14 degrees C. At the precooling time period, the taurine concentrations were increased (plasma 180 +/- 14 mumol/L; urine 4142 +/- 720 mumol/L [normal ranges 45.5 to 138.2 and 168 to 1890 mumol/L, respectively]). At the postcooling time period, taurine concentrations were significantly (p < .0001) decreased (54 +/- 6 and 802 +/- 160 mumol/L for plasma and urine, respectively). No correlation was found between taurine and creatine kinase activity, or between precooling temperature and taurinemia or taurinuria.

CONCLUSIONS

The source and clinical significance of the increased taurine concentrations are to be determined. The involvement of taurine in the regulation of core body temperature suggests that it may have an adaptive role in heatstroke.

Changes in peripheral blood lymphocyte subsets associated with marathon running

The percentage of peripheral blood mononuclear leukocytes that reacted with monoclonal antibodies specific for T-lymphocytes (CD3 cells), the helper/inducer subsets (CD4 cells), and cytotoxic/suppressor subsets (CD8 cells) of T-lymphocytes, and cells with NK activity (CD16 cells) were enumerated by fluorescence-activated flow cytometry for samples obtained immediately before and after the marathon running. It was found that long-term physical exercise resulted in a significant (P < 0.04 for relative and P < 0.008 for absolute lymphocytes) reduction in CD3 cells. A significant (P < 0.009) percentage change was also observed in B lymphocytes (CD19 cells) right after the marathon. The number of NK (CD16 cells) lymphocyte subsets was significantly (P < 0.05 for relative and P < 0.03 for absolute lymphocytes) changed. No significant changes were recorded for CD4, CD8, or CD4/CD8 ratios after the marathon run. A marked leukocytosis was noticed after the endurance exercise and the mean white blood cell (WBC number was increased from 7.8 +/- 2.6 to 22.9 +/- 2.8 x 10(9) cells x 1-1) count was changed by a factor of 2.9. The mean serum cortisol was significantly (P < 0.0001) increased. No hematocrit change was recorded in subjects pre- to post-run. The results of this study demonstrated that long-term physical exercise (marathon running) influenced the T-cell subsets remarkably and produced leukocytosis that was stress dependent and correlated with the increased serum cortisol levels and not the hemoconcentration.

Rearrangements of chromosome arm 3q in poorly differentiated nasopharyngeal carcinoma

Cell lines were established from fresh tumor biopsies from two Saudi patients with poorly differentiated nasopharyngeal carcinoma (NPC). Cytogenetic analysis on Giemsa-banded metaphase cells revealed complex, abnormal karyotypes in both patients with modal chromosome numbers of 77 and 52. A der(3)dup(3)(q25-q2?7) or t(3;?)(q27;?) was observed in both cell lines. The rearrangements involving chromosomes X, 1, 4, 6, 7, 8, 12, 13, 15, 17, and 22 in the first patient and 1, 6, and 22 in the second patient could represent clonal evolution.

Immunosuppression by human seminal plasma fractionated by DEAE Sephadex A-50 ion exchange chromatography

We fractionated the whole human seminal plasma on DEAE Sephadex A-50 ion exchange columns. Complete separation was achieved in seven peaks using different salt concentrations in phosphate buffer pH 6. The seminal plasma proteins were separated by sodium dodecyl-sulphate polyacrylamide gel electrophoresis. Human seminal plasma (SP) and its fractions were used in mixed lymphocyte reaction in vitro. Fractions 3, 4, and 7 were found to suppress the proliferation of human peripheral blood mononuclear cells to phytohemagglutinin and pokweed mitogen at a concentration of 10 micrograms ml-1 while stimulatory effect was observed at lower concentrations (1 microgram and 2.5 micrograms ml-1). Whole human SP and other fractions failed to suppress the proliferation of lymphocytes in vitro. Furthermore, the effect of human SP and its fractions was also investigated on phagocytic function of polymorphonuclear leukocytes (PMNs) using luminol dependent chemiluminescence assay stimulated with phorbol myristate acetate and opsonized yeast. Fractionated SP was found to have a suppressive effect on the luminol-dependent chemiluminescence of PMNs in the whole blood.

Peripheral T-cell lymphomas. Immunophenotype, lymphokine production, and immunologic functional characteristics of the lymph-node malignant T cells

Immunophenotype and functions of the malignant T cells to secrete various T-cell derived lymphokines and to respond in autologous mixed lymphocyte reaction (AMLR) and allogeneic mixed lymphocyte reaction (MLR) of the six patients with peripheral T-cell lymphomas (PTL) are presented. Three cases showed CD3/TcR alpha beta discordance (1 CD3+/TcR alpha beta-; 2 CD3-/TcR alpha beta+) and one showed absence of both these antigens (CD3-/TcR alpha beta-). In addition, we found that 50% of cases expressed CD25+, CD38+, and CD71+ activation antigens. The CD3/TcR alpha beta discordance and expressions of activation antigen noted in these cases were typical and similar to those reported from elsewhere. These malignant T cells from all cases whether CD25+ or CD25- (resting) expressed elevated interleukin-2 receptors (IL-2R) on stimulation with phytohemagglutinin (PHA) or human recombinant interleukin-2(rIL-2), and secreted elevated IL-2 by PHA, than do T cells from patients with tuberculosis (TB) or normal healthy controls. These malignant T cells also demonstrated elevated AMLR but deficient MLR B cells growth factor (BCGF) (except in one unusual case) secretion was increased, whereas B-cell differentiation factor (BCDF) secretion decreased. These results suggest that malignant T cells from lymph nodes of patients with PTL have uniform multiple immunologic defects in IL-2, BCGF, and BCDF lymphokine secretion and respond in AMLR and MLR, which do not correlate with immunophenotype or histologic types. These functions differentiate them from lymph-node T cells of patients with TB or blood T cells of normal healthy controls.

Cytogenetic investigations in three cell types of a Saudi family with ataxia telangiectasia

Chromosomal analyses were performed on lymphocytes, fibroblasts and lymphoblastoid cell lines derived from a Saudi family with ataxia telangiectasia (AT). The three siblings of a consanguineous marriage were all affected. The lymphocytes of the AT homozygotes (probands) showed an increase of 2- to 6-fold and 4- to 8-fold respectively, in the frequency of spontaneous and X-ray-induced chromosomal aberrations compared with controls, while the parents (obligate heterozygotes) of the patients showed no notable difference. The unirradiated lymphocytes from the oldest AT sibling, an 11-year-old boy (AT1), showed specific rearrangements involving chromosomes 7 and 14 [t(7;14)(q35;q12)] and 12 and 14 [t(12;14)(q23;q12)] in two different clones. The most severely affected sibling was a 9-year-old girl (AT2) who presented with a clone showing a novel rearrangement involving chromosomes 14 and 17, namely: del(14) (q31q32) and dup(17)(q21-q24). The lymphocytes from the third sibling, a 2-year-old boy (AT3), showed a t(2;14)(p24;q12). In addition, an inv(14)(q12q32) was observed in all three AT patients, while inv(7)(p14q35) was found only in patients 2 and 3. The lymphocytes from the AT parents and controls showed normal karyotypes. The breakpoints involving chromosomes 2, 12 and 17, observed in our studies, have rarely been reported in other series of AT patients. No non-random chromosomal rearrangements were observed either in the skin fibroblasts or in the lymphoblastoid cell lines derived from the AT patients, although all cell lines showed an increase in both spontaneous and radiation-induced chromosomal breaks per cell. The present study constitutes the first report on a cytogenetic analysis of a Saudi family with three AT siblings.

Endotoxemia and release of tumor necrosis factor and interleukin 1 alpha in acute heatstroke

To determine whether endotoxemia and release of tumor necrosis factor (TNF-alpha) and/or interleukin 1 alpha (IL-1 alpha) are involved in the pathogenesis of heatstroke, 17 adult patients with a mean rectal temperature of 42.1 +/- 0.2 degrees C were studied. Blood samples were taken on admission and after cooling was completed. TNF-alpha and IL-1 alpha levels were measured by enzyme-linked immunosorbent assay, and lipopolysaccharide (LPS) content was measured by the chromogenic substrate modification of the Limulus amebocyte lysate. TNF-alpha, IL-1 alpha, and LPS were elevated in all patients [199 +/- 25 (SE) pg/ml, 480.5 +/- 68.3 pg/ml, and 8.60 +/- 1.19 ng/ml, respectively, compared with normal control values of 31.4 +/- 8.4 pg/ml, 53.7 +/- 5.32 pg/ml, and less than 9 pg/ml]. There was no significant correlation between temperature and the circulating concentration of TNF-alpha, IL-1 alpha, and LPS. Postcooling TNF-alpha, IL-1 alpha, and LPS concentrations were significantly decreased but still above normal control values. The findings suggest that these mediators may have a role in the pathogenesis of heatstroke that could change the strategy of management.

Cytogenetic characterization of ataxia telangiectasia (AT) heterozygotes using lymphoblastoid cell lines and chronic gamma-irradiation

Lymphoblastoid cell lines (LCLs) derived from two patients identified as ataxia telangiectasia (AT), two obligate AT heterozygotes and two controls (healthy subjects with no known genetic disease or relationship to AT patients) were compared with respect to the induction of chromosomal breaks by acute and chronic gamma-irradiation. Although there was a considerable increase in the frequency of chromosomal breaks per cell in the LCLs of AT patients resulting from acute irradiation, the small increase occurring in the LCLs of the AT heterozygotes made it difficult to distinguish them from the controls. Following chronic gamma-irradiation, however, the frequency of chromosomal breaks per cell in the LCLs of the AT heterozygotes occupied a significantly distinct position from that of the controls. These observations suggested that the use of chronic irradiation may be a better choice in the cytogenetic characterization of AT heterozygotes.

Antibacterial activity of lomefloxacin against Brucella melitensis

The in vitro activity of lomefloxacin was tested against 114 clinical isolates of Brucella melitensis. Comparison was made with ciprofloxacin, tetracycline, gentamicin, rifampin, and trimethoprim-sulfamethoxazole. Lomefloxacin inhibited 113 (99.1%) of the 114 strains tested at less than or equal to 0.5 microgram/ml. It was comparable to ciprofloxacin, tetracycline and gentamicin in antimicrobial potency. One strain that was previously susceptible to ciprofloxacin and had become resistant after the patient was treated with ciprofloxacin showed cross-resistance to lomefloxacin.