Cytokine production by human fetal microglia and astrocytes. Differential induction by lipopolysaccharide and IL-1 beta

As part of a study on the role of cytokines in central nervous system development and dysfunction, we determined the pattern of cytokine production in highly purified cultures of microglia and astrocytes isolated from second-trimester human fetal brains. Levels of TNF-alpha, IL-1 beta, and IL-6 mRNA and protein were determined by Northern blot analysis and ELISA before and after stimulation with LPS, TNF-alpha, or IL-1 beta. In microglia, LPS induced mRNA for all three cytokines. High protein levels of IL-6 and TNF-alpha were also found in the medium, whereas IL-1 beta protein was mostly cell associated. IL-1 beta also induced message for all three cytokines, in the rank order of IL-1 beta > IL-6 > TNF-alpha. TNF-alpha induced mRNA and protein for IL-1 beta but not for TNF-alpha or IL-6. In contrast, LPS failed to stimulate either mRNA or protein expression for any of the three cytokines in astrocytes. On the other hand, IL-1 beta provided a strong stimulus for astrocytes. IL-1 beta induced mRNA and protein for both TNF-alpha and IL-6, but the kinetics of the response differed for the two cytokines. TNF-alpha mRNA and protein levels peaked early (at 4 h and 16 h, respectively) and were undetectable by 72 h, whereas IL-6 mRNA peaked later (at 16 h) and protein levels continued to accumulate in the medium through 72 h. IL-1 beta did not induce IL-1 beta mRNA or protein in astrocytes. TNF-alpha did not induce expression of any of the cytokines in astrocytes. In conclusion, our results demonstrate that cytokine production can be induced in human fetal microglia and astrocytes but that the stimuli for induction differed significantly for the two cell types. Whereas LPS was a potent stimulus for microglia, astrocytes primarily responded to IL-1 beta. The data further suggest that microglia may be key regulators of astrocyte response, working primarily through the expression of cell-associated IL-1 beta.

Cytokine production by human fetal microglia and astrocytes. Differential induction by lipopolysaccharide and IL-1 beta

As part of a study on the role of cytokines in central nervous system development and dysfunction, we determined the pattern of cytokine production in highly purified cultures of microglia and astrocytes isolated from second-trimester human fetal brains. Levels of TNF-alpha, IL-1 beta, and IL-6 mRNA and protein were determined by Northern blot analysis and ELISA before and after stimulation with LPS, TNF-alpha, or IL-1 beta. In microglia, LPS induced mRNA for all three cytokines. High protein levels of IL-6 and TNF-alpha were also found in the medium, whereas IL-1 beta protein was mostly cell associated. IL-1 beta also induced message for all three cytokines, in the rank order of IL-1 beta > IL-6 > TNF-alpha. TNF-alpha induced mRNA and protein for IL-1 beta but not for TNF-alpha or IL-6. In contrast, LPS failed to stimulate either mRNA or protein expression for any of the three cytokines in astrocytes. On the other hand, IL-1 beta provided a strong stimulus for astrocytes. IL-1 beta induced mRNA and protein for both TNF-alpha and IL-6, but the kinetics of the response differed for the two cytokines. TNF-alpha mRNA and protein levels peaked early (at 4 h and 16 h, respectively) and were undetectable by 72 h, whereas IL-6 mRNA peaked later (at 16 h) and protein levels continued to accumulate in the medium through 72 h. IL-1 beta did not induce IL-1 beta mRNA or protein in astrocytes. TNF-alpha did not induce expression of any of the cytokines in astrocytes. In conclusion, our results demonstrate that cytokine production can be induced in human fetal microglia and astrocytes but that the stimuli for induction differed significantly for the two cell types. Whereas LPS was a potent stimulus for microglia, astrocytes primarily responded to IL-1 beta. The data further suggest that microglia may be key regulators of astrocyte response, working primarily through the expression of cell-associated IL-1 beta.

[The number, distribution and effects of interleukin-2 receptor and CD4 antigens in benign and malignant lymphoproliferative diseases]

An analysis of immunophenotypes was made in benign and malignant lymphoproliferative diseases (35 cases) and short cultured lymphocytes of chronic tonsillitis (15 cases). The number, distribution and variation of interleukin-2 receptor (IL-2R, CD25) and CD4 positive cells in the above lesions were studied. The results showed that (1) there were more or less IL-2R+ and CD4+ cells presented in the tissues of benign lymphoproliferative lesions; (2) IL-2R antigen was also presented in some tumor and non-tumor cells with CD4+ reaction but it was not found in the cells with CD1+ or/and CD8+ reactions; (3) IL-2R and CD4 antigens were expressed in the proliferated lymphocytes stimulated by PHA. Although IL-2R antigen is not a specific marker to certain types of lymphocytes, it has some relations with immunophenotypes of lymphocytes. The functions and effects of IL-2, IL-2R and helper T lymphocytes were also discussed.

[A clinicopathological and immunohistochemical study of 49 cases of necrotizing lymphadenitis]

A clinicopathological and immunohistiochemical study of 49 cases of necrotizing lymphadenitis was made. Twenty-four patients were male and twenty-five female with the M:F ratio of 0.96:1. The patients ranged in age from 9 to 62 years with a mean of 26. Forty-nine patients had superficial lymphadenopathy, and twenty-two were accompanied by fever. The results also showed that there was multifoci necrosis present in the involved lymph nodes, particularly in the cortex or/and paracortex, with variable numbers of small lymphocytes, immunoblasts, histocytes and phagocytes, the latter with phagocytized nuclear debris derived from necrotizing T lymphocytes. However, granulocytes and plasmacytes were generally absent, and B lymphocytes rare. The pathogenesis of this disease remains unknown and the pathogen has not been found by Gram, Giemsa, PAS, Ziehl-Neelsen and Warthin-Starry stain. The diagnosis, differential diagnosis and etiology of this disease are discussed. We support the suggestion that this entity be called "Kikuchi-Fujimoto's disease" rather than "Histiocytic necrotizing lymphadenitis".

The antimicrobial effect of a structural variant of subtilin against outgrowing Bacillus cereus T spores and vegetative cells occurs by different mechanisms

Subtilin is a ribosomally synthesized antimicrobial peptide that contains several unusual amino acids as a result of posttranslational modifications. Site-directed mutagenesis was employed to construct a structural variant of subtilin in which the unusual dehydroalanine (Dha) residue at position 5 was changed to alanine. Proton nuclear magnetic resonance spectroscopy, amino acid composition, and N-terminal sequence analysis established that the mutation did not disrupt posttranslational processing of the precursor peptide. This mutant subtilin was devoid of antimicrobial activity as assessed by its lack of inhibitory effects on outgrowth of Bacillus cereus T spores. However, this same mutant subtilin was fully active with respect to its ability to induce lysis of vegetative B. cereus T cells. Because an intact Dha-5 residue is required in the one instance but not in the other, it was concluded that the molecular mechanism by which subtilin inhibits (without lysis) spore outgrowth is not the same as the mechanism by which it inhibits (with lysis) vegetative cells.

Macrophage colony-stimulating factor in human fetal astrocytes and microglia. Differential regulation by cytokines and lipopolysaccharide, and modulation of class II MHC on microglia

CSF-1 is a growth factor that selectively promotes the proliferation, survival, and differentiation of cells of the mononuclear phagocyte series. As part of a study on the role of cytokine and hematopoietic growth factors in central nervous system (CNS) development and inflammation, we examined the expression of CSF-1 in dissociated glial cells cultured from human fetal CNS tissue. CSF-1 mRNA and protein were constitutively expressed by astrocytes. The steady state level of CSF-1 mRNA was markedly up-regulated by both IL-1 beta and TNF-alpha in a time- and dose-dependent manner, whereas only a minimal increase was detected after stimulation with LPS. In unstimulated astrocyte cultures, CSF-1 protein levels gradually increased to 3.5-fold base-line values by 96 h and were significantly increased by all three stimulants in the order of IL-1 > or = TNF > LPS. Low levels of CSF-1 mRNA and protein were also detected in unstimulated microglia cultures. In contrast to astrocyte cultures, CSF-1 mRNA and protein increased significantly after stimulation with LPS, but changed only minimally after exposure to TNF-alpha or IL-1 beta. The effect of CSF-1 on cell proliferation, morphology, and class II MHC Ag expression was determined in highly enriched cultures of microglia and astrocytes. Microglia treated with CSF-1 showed a modest level of proliferation and differentiation into rod-shaped cells, whereas neither cell number nor shape was changed in astrocyte cultures. Interestingly, marked inhibition of both basal and IFN gamma-induced class II MHC Ag expression was observed in microglial cells cultured in the presence of CSF-1, whereas no effect was detected in astrocytes. These results suggest the possibility that in situ production of CSF-1 in the CNS may regulate normal glial cell development and contribute to the immunologic status of the CNS through the down-regulation of class II MHC expression.

Macrophage colony-stimulating factor in human fetal astrocytes and microglia. Differential regulation by cytokines and lipopolysaccharide, and modulation of class II MHC on microglia

CSF-1 is a growth factor that selectively promotes the proliferation, survival, and differentiation of cells of the mononuclear phagocyte series. As part of a study on the role of cytokine and hematopoietic growth factors in central nervous system (CNS) development and inflammation, we examined the expression of CSF-1 in dissociated glial cells cultured from human fetal CNS tissue. CSF-1 mRNA and protein were constitutively expressed by astrocytes. The steady state level of CSF-1 mRNA was markedly up-regulated by both IL-1 beta and TNF-alpha in a time- and dose-dependent manner, whereas only a minimal increase was detected after stimulation with LPS. In unstimulated astrocyte cultures, CSF-1 protein levels gradually increased to 3.5-fold base-line values by 96 h and were significantly increased by all three stimulants in the order of IL-1 > or = TNF > LPS. Low levels of CSF-1 mRNA and protein were also detected in unstimulated microglia cultures. In contrast to astrocyte cultures, CSF-1 mRNA and protein increased significantly after stimulation with LPS, but changed only minimally after exposure to TNF-alpha or IL-1 beta. The effect of CSF-1 on cell proliferation, morphology, and class II MHC Ag expression was determined in highly enriched cultures of microglia and astrocytes. Microglia treated with CSF-1 showed a modest level of proliferation and differentiation into rod-shaped cells, whereas neither cell number nor shape was changed in astrocyte cultures. Interestingly, marked inhibition of both basal and IFN gamma-induced class II MHC Ag expression was observed in microglial cells cultured in the presence of CSF-1, whereas no effect was detected in astrocytes. These results suggest the possibility that in situ production of CSF-1 in the CNS may regulate normal glial cell development and contribute to the immunologic status of the CNS through the down-regulation of class II MHC expression.

An intermediate loading rate technique for the determination of mechanical properties of human femoral cortical bone

An experimental method to evaluate the mechanical properties of human femoral cortical bone under an intermediate strain rate of 4 x 10(-2) s-1 is presented. The dynamic loading was developed by dropping weights from various heights; results were obtained for Young's modulus and Poisson's ratio when the specimens were loaded along the longitudinal axis of the femur. The results were compared with those under a slow strain rate of 2 x 10(-5) s-1 and a fast strain rate of 1 x 10(-2) s-1. It was found that Young's modulus for the intermediate strain rate is 10.5% higher than for the slow strain rate and 10% lower than for the fast strain rate. Poisson's ratio did not show any significant variation for the above three strain rates. The results were compared with those given previously by other investigators.

Enhancement of the chemical and antimicrobial properties of subtilin by site-directed mutagenesis

Subtilin and nisin are gene-encoded antibiotic peptides that are ribosomally synthesized by Bacillus subtilis and Lactococcus lactis, respectively. Gene-encoded antibiotics are unique in that their structures can be manipulated by mutagenesis of their structural genes. Although subtilin and nisin share considerable structural homology, subtilin has a greater tendency than nisin to undergo spontaneous inactivation. This inactivation is a accompanied by chemical modification of the dehydroalanine at position 5 (DHA5) with a kinetic first-order t1/2 of 0.8 days. It was hypothesized that the R group carboxyl of Glu4 in subtilin participates in the chemical modification of the adjacent DHA5. Noting that nisin has Ile at position 4, site-directed mutagenesis was used to change Glu4 of subtilin to Ile, in order to eliminate this carboxyl-group participation. The DHA5 of this mutant subtilin (E4I-subtilin) underwent modification with a t1/2 of 48 days, which is 57-fold slower than natural subtilin, and the rate of loss of biological activity dropped by a like amount. These results suggest that an intact DHA5 is critical for subtilin activity against bacterial spore outgrowth. A double mutant of subtilin, in which the DHA5 residue of E4I-subtilin was mutated to Ala was devoid of detectable inhibition against spore outgrowth. The specific activity of E4I-subtilin was 3-4-fold higher than natural subtilin, suggesting that an increase in the hydrophobicity of the N-terminal end of the molecule enhances activity. These are the first mutants of subtilin that have been reported, and E4I-subtilin is the first example of any lantibiotic whose properties have been improved by mutagenesis. In order to carry out the mutagenesis, a host-vector pair was constructed that permits a deletion replacement in which the natural subtilin gene is replaced by the mutant gene at the normal location in the chromosome. This maintains normal gene dosage and regulatory responses, as well as eliminates ambiguities caused by expression of the normal and mutant genes in the same cell.

[The preparation and clinical use of a radioimmunoassay CA125 kit for the diagnosis of epithelial ovarian cancer]

A self-made radioimmunoassay CA125 kit (using OC125 monoclonal antibody ascites offered by Dr. Bast Laboratory which was purified, solidified and labelled with 125I) was used for serum determination in 80 patients with epithelial ovarian cancer and in 40 standard antigen samples. The results demonstrated a statistically significant correlation between our self-made CA125 kit and an imported CENTOCOR CA125 kit (P < 0.001). Clinical experience before operation in 40 patients with epithelial ovarian cancer, 34 with endometriosis and 39 with other malignant ovarian tumors suggested that the self-made CA125 kit was more sensitive in diagnosing epithelial ovarian cancer than the other two diseases. Post-operative follow-up in 86 non-recurrent cases and 101 recurrent cases showed a 96% positive predictive rate and 91% negative predictive rate. It is concluded that self-made CA125 kit is very useful in monitoring epithelial ovarian cancer.

Effects of the expression of mammalian annexins in yeast secretory mutants

The hypothesis that calcium-dependent membrane-binding proteins of the annexin family can influence intracellular membrane trafficking was tested by expressing five mammalian annexins in wild-type yeast cells (Saccharomyces cerevisiae) and in 13 yeast secretory (sec) mutants. Expression of human synexin (annexin VII) inhibited the growth of sec2, sec4 and sec15 mutants at a semi-permissive temperature. These three sec mutants are defective in the final step in the secretory pathway, the process of exocytosis. The inhibition of growth correlated with reduced viability and increased accumulation of internal invertase in these mutants when expressing synexin. Bovine endonexin (annexin IV) partially suppressed the growth defect of a sec2 mutant incubated at a semi-permissive temperature. Human synexin, human lipocortin (annexin I), and murine p68 (annexin VI) reduced the lag time associated with adaptation of sec2 mutants to galactose-containing medium. These interactions suggest that the annexins may influence specific steps in membrane trafficking associated with cell growth, secretion and plasma membrane remodelling.

Primary care arrangements and access to care among African-American women in three Chicago communities

African-American women of child-bearing age residing in three high-risk communities in Chicago were surveyed regarding their primary care arrangements and access to care (n = 552). This study examined factors which differentiated women who used office-based practices from those who used institutional settings (community clinics, health department clinics, hospital-based clinics) for primary care. Results of multivariate analysis indicate that women who used office-based practices were more likely than those who used institutional settings to see the same provider, to walk to their provider, to have less travel time and to walk in without an appointment. They were less likely to be hospitalized in the past year and less likely to report the availability of family planning at their usual source of care. Satisfaction with care, insurance status and sociodemographic characteristics were not associated with use of a particular facility type. Implications for organizing comprehensive health services for this population are discussed.

[Detection of human papillomavirus (HPV) DNA in carcinoma of uterine cervix and genital tract diseases in Jiangsu province, China]

Pst-1 cleaved DNA restriction fragment length polymorphism (RFLP) of biopsy samples from 41 patients with squamous cell carcinoma of uterine cervix collected in Jiangsu province, China were examined for HPVs by Southern blot hybridization using HPV 16 DNA as a probe. 20 of the 41 samples were positive for HPVs when hybridized under non-stringent condition. HPV was not detectable in samples collected in the same time period from patients with cervical adenocarcinoma (N = 2), vaginal carcinoma (N = 3), vulval carcinoma (N = 1) and benign cervicitis (N = 8). Of the 20 positive samples, 7 (17.1%) had CHPV X1, a new type of NPV previously discovered is China, 6 (14.6%) had HPV 16, 4 (9.9%) had HPV 31, and in 3 (7.2%) the HPV type is as yet undetermined. Our data indicate that HPV 16 and CHPV X1 may be more closely related to cancer of the uterine cervix in Jiangsu province.

Characterization of the rate-dependent effects of ethmozine on conduction, in vivo, and on the sodium current, in vitro, in the newborn heart

We evaluated the effects of ethmozine on resting conduction intervals, myocardial refractory periods and His-Purkinje and intraventricular conduction in vivo in 11 neonatal dogs aged 7 to 16 days. Ethmozine produced significant prolongation in resting sinus cycle length (P < .05), in the atrioventricular nodal (P < .001) and His-Purkinje conduction time (P < .01) intervals and in the QRS duration (P < .01). Ventricular, but not atrial refractory periods were significantly prolonged (P < .05). Rate-dependent changes in His-Purkinje and intraventricular conduction were demonstrated after ethmozine by direct pacing of the bundle of His and right ventricular pacing. The development of steady-state conduction delay at a paced cycle length of 200 msec was characterized by a time constant (tau on) of 23.5 beats. The time constant of diastolic recovery (tau off) from rate-dependent conduction delay, determined during His bundle extrastimulation, was 171 msec. Ethmozine was highly proarrhythmic. A total of 7 arrhythmias were induced in 6 out of 12 neonates after administration of ethmozine. We also characterized ethmozine block of cardiac sodium channels in isolated neonatal canine ventricular myocytes using the whole cell variation of the patch clamp technique. Ethmozine (1.3-40 microM) produced a use-dependent block of cardiac Na channels that was dependent upon both drug concentration and pulse duration. Drug binding to inactivated channel states accounted for the observed use-dependent block. The time constant of recovery from use-dependent block ranged between 10 and 30 sec at 16 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Enzymatic semisynthesis of a superpotent analog of human growth hormone-releasing factor

A superpotent analog of human growth hormone-releasing factor, [desNH2Tyr1,D-Ala2,Ala15]-GRF(1-29)-NH2 (4), was prepared from the precursor, [Ala15,29]-GRF(4-29)-OH (1), by a two-step enzymatic semisynthesis. The amidated C-terminus, essential for high biological potency, was obtained via a carboxypeptidase Y-catalyzed exchange of Ala29-OH for Arg29-NH2 to produce [Ala15]-GRF(4-29)-NH2 (2). The N-terminal desNH2Tyr-D-Ala moiety, which greatly increases in vivo duration of action, was then incorporated by V8 protease-catalyzed condensation of segment 2 with desNH2Tyr-D-Ala-Asp(OH)-OR [R = CH3CH2- (3a) or 4-NO2C6H4CH2-(3b)]. The main focus of this report was to develop conditions to use the V8 protease-catalyzed coupling while avoiding a competing cleavage of the proteolytically-sensitive Asp25-Ile26 bond in GRF. Conversion of 2 to 4 in couplings employing the alpha-ethyl ester of the acyl component 3a was limited to about 60% by competing proteolysis at Asp25-Ile26. This system was adequate for preparing, isolating, and fully characterizing the target analog 4 and identifying the side products. The 4-nitrobenzyl ester 3b proved to be a superior substrate, resulting in 90% conversion of 2 to 4 with no detectable loss to proteolysis and requiring significantly lesser amounts of catalyst. These results demonstrate that enzymatic semisynthesis of a biologically-active peptide amide which contains unnatural amino acids at the N-terminus can be achieved from a biosynthetic precursor in good yield and purity.