Cytokine production by T helper cell subpopulations during prolonged in vitro stimulation.

In man, CD4+ T cells can be divided into phenotypically distinguishable subsets with different function whereas CD4+ T cells with the opposite pheno-CD45RO and low levels of CD45RA antigen provide help for mitogen-induced immunoglobulin production whereas CD4+ cells with the opposite phenotype suppress immunoglobulin production. However, studies examining cytokine production by phenotypically defined CD4+ T cell subsets have led to different conclusions. Further, very few studies have examined cytokine production by freshly isolated CD4+ T cell subsets during extended culture periods. Thus, we examined the production of several cytokines (at various time points) by CD4+ T cell subsets that were isolated in several ways, and stimulated with PWM, Con A, and PHA in a well-defined serum-free culture system. We found that CD4+, CD45RA- (or CD45RO+) T cells consistently produced the most IL-2, IFN-gamma, and TNF-alpha after mitogen stimulation for 2 days. PWM induced the largest quantities of each cytokine, although a similar pattern of production was observed in response to Con A and PHA. We were unable to detect IL-4 production by mononuclear cells and CD4+ T cell subsets suggesting that, if it is produced at all, IL-4 is produced in extremely small quantities. When the culture period of initially CD45RO- T cells was extended beyond 2 days, the culture supernatant contained increased quantities of each cytokine and the cells in the culture had an increased number of cells expressing CD45RO antigen. Together, these data indicate that CD4, CD45RA- (or CD45RO+) T cells in peripheral blood are the major producers of IL-2, IFN-gamma, and TNF-alpha following short-term mitogen stimulation, and that phenotypically defined peripheral blood T cell subsets do not maintain a distinct pattern of cytokines during extended culture periods.     

Effect of liposomes containing sodium butyrate conjugated with anti-CD19 monoclonal antibody on in vitro and in vivo growth of malignant lymphoma.

A differentiation-inducer, sodium butyrate (SB), encapsulated in liposomes conjugated covalently to a monoclonal antibody directed to CD19 antigen, was successfully targeted to human lymphoma cell lines SKLY-18 and Ramos grown in vitro and in vivo in nude mice. Various control liposomes (lacking SB, lacking antibody, containing SB alone, or coupled to irrelevant antibody) were not effective targeters. Growth of tumor cells not expressing the relevant antigen was unaffected by the antibody-SB-liposome complex. Suppression of lymphoma growth in vivo was remarkable, and tumor regression was observed under certain conditions, although changes in morphology were not clearly observed. In view of the practical nonexistence of "tumor-specific" antigens, targeting of differentiation-inducers or growth modifiers, rather than cytotoxic drugs, to tumor cells, as exemplified in these experiments, may provide a useful approach for conversion of highly malignant to less malignant tumors, although the exact mechanism of the growth inhibitory effect on B-cell lymphoma of the anti-CD19 antibody-SB-liposome complex is unknown.     

Posterior chamber collamer phakic intraocular lens for myopia and hyperopia.

PURPOSE: To assess the feasibility of correcting refractive errors using a foldable posterior chamber phakic intraocular lens. METHODS: Thirty-four foldable posterior chamber phakic intraocular lenses (STAAR Collamer intraocular lens) were consecutively implanted by the same surgeon (PMP) in 19 myopic eyes and 15 hyperopic eyes. In myopic eyes, mean preoperative spherical equivalent refraction was -16.65 +/-3.37 D (range, -8.12 to -21.25 D). In hyperopic eyes, mean preoperative spherical equivalent refraction was +7.77+/-2.08 D (range, +4.75 to +11.75 D). Mean follow-up was 12 months (range, 6 to 18 mo). Two hyperopic eyes were not included in the data analysis because of removal of the intraocular lens due to pupillary block. RESULTS: Myopic eyes (n=19)-Mean spherical equivalent postoperative refraction was -1.51+/-1.37 D (range, -5.50 to+0.38 D). Postoperative refraction was within +/-0.50 D in 4 eyes (21.05%) and within +/-1.00 D in 8 eyes (42.10%). Uncorrected visual acuity was 20/40 or better in 12 eyes (63.15%) and 20/25 or better in 3 eyes (15.78%). No eye had an uncorrected visual acuity of 20/20 or better. Spectacle-corrected visual acuity was 20/40 or better in all eyes, 20/25 or better in 12 eyes (63.15%), and 20/20 or better in 1 eye (5.26%). Spectacle-corrected visual acuity was unchanged in 10 eyes (52.63%) and improved in 9 eyes (47.36%). A retinal detachment developed in 1 eye (5.26%). Hyperopic eyes (n=15)-Mean spherical equivalent postoperative refraction was +0.02+/-0.64 D (range, -1.00 to +1.50 D). Postoperative refraction was within +/-0.50 D in 9 eyes (69.25%) and +/-1.00 D in 12 eyes (92.30%). Uncorrected visual acuity was 20/40 or better in 6 eyes (46.15%) and 20/25 or better in 3 eyes (20.25%). No eye had an uncorrected visual acuity of 20/20 or better. Spectacle-corrected visual acuity was 20/40 or better in 7 eyes (53.84%), 20/25 or better in 6 eyes (46.15%), and 20/20 or better in 2 eyes (15.38%). Spectacle-corrected visual acuity was unchanged in 10 eyes (76.92%), significantly improved in 2 eyes (15.38%), and worse in 1 eye (7.69%). Two of 15 eyes (13.33%) developed a severe pupillary block necessitating removal of the implants. One eye (7.69%) developed an anterior subcapsular cataract. CONCLUSIONS: Refractive predictability appears better for hyeropia than for myopia using the STAAR Collamer foldable posterior chamber phakic intraocular lens. In hyperopic eyes, development of pupillary block may occur.     

Nonhuman primates express human leukemia-associated antigens

Serologic studies using four murine monoclonal antibodies specific for the common acute lymphoblastic leukemia antigen (CALLA) and five monoclonal antibodies specific for the gp24 surface antigen indicate that these leukemia-associated antigens are present on cells of comparable tissues in man and in four nonhuman primates. As in man, adherent cell populations obtained from skin, lung, and bone marrow of Macaca fascicularis, M mulatta, M nemestrina, and Papio cynocephalus react with these antibodies. Similarly, granulocytes from both man and these nonhuman primates bind CALLA- and gp24-specific antibodies. Radioimmune precipitation experiments confirm the identity of these antigens. Our studies suggest that nonhuman primates can be used to screen serologic reagents to leukemia-associated antigens for potential toxic effects on normal tissues prior to their use in man. Similarly, nonhuman primates could be employed to assess the possible role of antigen-positive stromal cells in the reconstitution of bone marrow following transplantation.     

Effects of methoxychlor, dieldrin and lindane on sea urchin fertilization and early development

We have studied the effects of methoxychlor (MXC), dieldrin, and lindane on fertilization and early development of sea urchin egg. These organochlorine pesticides have often been found in polluted ground and water near agricultural sites, and have therefore been detected from time to time in the food chain and in drinking water. They have been reported to alter various reproduction functions in various animals including marine populations. We observed that the rate of fertilization decreased when the sperm was incubated with dieldrin or lindane. Treatment of eggs with each pesticide did not prevent fertilization, but increased the rate in polyspermy, delayed or blocked the first mitotic divisions, and altered early embryonic development. Moreover, all pesticides could alter several intracellular biochemical pathways that control first mitotic divisions and early development, including intracellular calcium homeostasis, MPF (mitosis promoting factor) activity and formation of the bipolar mitotic spindle. We found that lindane was the most potent of the three pesticides to alter all biochemical events. All these effects were observed at relatively high concentrations. However, bio-accumulation in sediments and aquatic organisms have been reported. Sea urchin eggs may then be in contact with very high concentrations of these pesticides in areas where these pesticides are not handled or stocked properly, and then develop into abnormal embryos.     

Assessment of peri-neonatal mortality and morbidity risk in twin pregnancy

A case control study on peri-neonatal mortality and morbidity rates in 154 twin pregnancies has been performed. The mortality rates along with main neonatal morbidity factors were evaluated in relation to the birth weight and gestational age. The risk of death in peri-neonatal period was 17 times greater (relative risk 17.30) (p less than .00005) in newborns weighing less than 2000 g and about 15 times (r.r. 14.53) (p less than .00005) in twins born before 34th week of gestational age with respect to the controls. The Apgar score of the 2nd twin was lower than that of the 1st, both at 1' (p less than .05) and 5' (p less than .025). The development of HMD was strongly influenced by the gestational age when less than 34th week (r.r. 15.89) (p less than .00005). No difference in incidence was found between the newborns with gestational age between 34-37 weeks and those at term. The potential implications of these findings on obstetric and neonatologic treatment of LBW and VLBW twins was discussed.     

Ia determinants on human T-cell subsets defined by monoclonal antibody. Activation stimuli required for expression

The nature of Ia antigens which appear on human T cells after activation and the stimuli required for their expression was examined utilizing a monoclonal antibody reactive with the Ia antigen framework. T cells were purified using monoclonal antibodies directed either at the entire T-cell population (OKT3) or the T-cell inducer subset (OKT4). By indirect immunofluorescence, it was shown that the human T-cell population contains no detectable Ia+ cells in the resting state. In contrast, in excess of 60% of the T-cell population expresses Ia antigen after alloactivation in the mixed lymphocyte culture. Moreover, these Ia antigens are expressed within both the OKT4+ and OKT4- subsets. Similarly, phytohemagglutinin and concanavalin A induced approximately 20% of peripheral T cells to express Ia antigen and the expression of these antigens is not restricted to either OKT4 subset. In contrast, only the inducer T-cell population which proliferates maximally to soluble antigen expresses Ia antigens after activation by tetanus toxoid. Thus, the expression of human Ia antigens on unique T-cell subsets depends upon the activation stimuli utilized and ability of the individual subset to respond to a given stimulus. Additional studies indicated that Ia antigens appear on previously Ia- T cells after activation and do not result from clonal expansion of a small subset of Ia+ T cells.