Vertebral compression fracture as a presenting feature of acute lymphoblastic leukemia in children

Twenty-four (1.6%) of 1466 children with acute lymphoblastic leukemia (ALL) treated at St. Jude Children's Research Hospital had vertebral compression fractures at diagnosis. When compared with patients without this complication, they were more likely to have good prognostic features, including a leukocyte count of greater than 25 X 10(9)/l, a leukemic cell DNA index of greater than 1.15, and hyperdiploidy (greater than 50 chromosomes). Complete remission of ALL was induced in all patients, and symptoms of vertebral compression fractures abated following antileukemia therapy. Although the diagnosis of ALL was delayed for some patients because this unusual presenting complication was not recognized as such, their treatment outcome was as good as that for other children with "standard-risk" ALL.     

Evaluation of Twenty-Three Blood Culture Media

Several investigators have evaluated clinically a variety of commercially available blood culture media. No agreement has been reached as to which of these media is optimal for detection of bacteremia. The purpose of this study was to determine the rate of recovery of microorganisms from various blood culture media. A total of 23 blood culture media were inoculated with 7 to 15 microorganisms per bottle in the presence or absence of an erythrocyte-serum mixture. The results demonstrated that blood culture media differed in their ability to support the growth of microorganisms. At 4 days after inoculation, only 10 of the 23 blood culture media supported the growth of 91% (10 of the 11) or more of the test microorganisms. The recovery rate of microorganisms depended not only upon the type of medium but also upon the manufacturer of the type of blood culture medium. The addition of an erythrocyte-serum mixture to the blood culture media did not influence the difference in the recovery rate of microorganisms among media and the same type of medium prepared by different manufacturers. The majority (15 of the 23) of the blood culture media supplemented with the erythrocyte-serum mixture failed to support the growth of 91% or more of the test microorganisms at 4 days after inoculation. These results have demonstrated that blood culture media need to be improved. Better quality control measures should also be implemented to evaluate commercial blood culture media.     

Comparison of modified Bordet-Gengou and modified Regan-Lowe media for the isolation of Bordetella pertussis and Bordetella parapertussis.

Culture and fluorescent-antibody methods for detection of Bordetella species were evaluated by two state public health laboratories. Field-inoculated plates of Regan-Lowe agar medium were most useful if incubation was initiated on the day of collection. Regan-Lowe and Bordet-Gengou media were comparable for subculturing nasopharyngeal specimens that were transported and enriched in half-strength Regan-Lowe agar. Maximum sensitivity was achieved when the media were used in parallel. Fluorescent-antibody-stained smears of nasopharyngeal specimens were more sensitive for detection of Bordetella pertussis than for detection of Bordetella parapertussis. The fluorescent-antibody method, however, was too insensitive for use without culture.     

Greater Resistance to Extinction of Electrodermal Responses Conditioned to Potentially Phobic CSs: A Noncognitive Process?

Previous results have suggested that electrodermal responses classically conditioned to potentially phobic CSs (e.g., pictures of snakes or spiders) are highly resistant to extinction and occur largely independently of cognitive expectancies. In order to test stringently for these possibilities, 144 college student subjects were administered differential classical conditioning acquisition and extinction paradigms while expectancies of the shock UCS were closely monitored. Half the subjects had potentially phobic CSs, whereas the other half had neutral CSs. Regardless of type of CS, during acquisition no evidence of electrodermal conditioning was found among subjects unaware of the CS?UCS contingency, nor was conditioning found on the pre-aware trials of subjects who became aware. During extinction, there was significantly greater resistance to extinction of electrodermal responses conditioned to potentially phobic CSs as well as a similar trend with expectancies of the UCS. However, when expectancies were equated, there was no greater resistance to extinction of electrodermal responses conditioned to potentially phobic CSs. Thus, while electrodermal responses conditioned to potentially phobic CSs did exhibit greater resistance to extinction, this conditioning was no more independent of expectancies than is conditioning with neutral CSs.     

Passive transfer of resistance to frambesial infection in hamsters.

The immune mechanism by which hamsters acquire resistance to infection with Treponema pertenue, the causative agent of frambesia, or yaws, has not been elucidated. Serum or cells (spleen or lymph node) obtained from hamsters resistant to frambesial infection were transferred to normal syngenic recipients, who are subsequently infected with T. pertenue. The following parameters were used to measure the ability of immune serum of cells to confer resistance on recipient hamsters to frambesial infection: inhibition of the development of cutaneous lesions, decreased weight, and number of treponemes in the inguinal lymph nodes. This investigation demonstrated that immune serum conferred protection on recipient hamsters infected with T. pertenue. Discontinuation of the administration of immune serum (18 days after frambesial infection) did not result in the development of cutaneous lesions. Since the inguinal lymph nodes contained a sizeable number of treponemes (2.6 X 10(5)), immune serum failed to prevent frambesial infection. Recipients of immune spleen or lymph node cells initially developed frambesial lesions 9 days after infection. The frambesial lesions began to resolve 12 to 14 days after infection and by day 21 had completely regressed. These results illustrated that humoral factors and cells are involved in resistance of the hamster to frambesial infection.     

Role of L3T4+ and 38+ T-cell subsets in resistance against infection with Treponema pallidum subsp. pertenue in hamsters.

The protective immunity conferred by T-cell subsets against infection with Treponema pallidum subsp. pertenue was studied. We demonstrated that hamster T cells can be separated into two subsets by monoclonal antibody (MAb) GK 1.5 (anti-L3T4) and MAb 38. Eighty-five percent of hamster thymocytes were L3T4+ and 87% were 38+ cells; 84% were dual positive for MAbs anti-L3T4 and 38. In the peripheral lymph nodes, however, the L3T4+ and 38+ T cells were mutually exclusive according to two-color immunofluorescence analysis. The two T-cell subsets were found to be functionally distinct according to their secretion of interleukin 2 (IL-2) when stimulated with concanavalin A. The L3T4+ cells secreted IL-2 and had characteristics of T helper cells, while the 38+ cells did not secrete IL-2 and appeared to be T cytotoxic-suppressor cells. Transfer of 4 x 10(6) helper or cytotoxic-suppressor T lymphocytes from T. pallidum subsp. pertenue-immune hamsters protected irradiated naive hamsters against challenge with this subspecies. IL-2 production could still be detected in the irradiated recipients 12 days after irradiation of naive recipients, although at a low level. This suggests that the remaining lymph node cells could support the survival and expansion of the infused cytotoxic-suppressor T cells. No accumulation of macrophages was observed in regional lymph nodes of immune T-cell recipients within 10 days of infection. Instead, there was an influx of polymorphonuclear neutrophils in all animals injected with T. pallidum subsp. pertenue. This report demonstrates that hamster T cells can be separated into two phenotypically and functionally distinct subsets and that both T-cell subsets confer protection against challenge with T. pallidum subsp. pertenue.     

Phagocytosis of opsonized Treponema pallidum subsp. pallidum proceeds slowly.

Macrophages were found to phagocytize Treponema pallidum subsp. pallidum attached to polycarbonate filters. This environment simulated the in vivo interaction of surface-adherent treponemes with macrophages. The phagocytosis of T. pallidum subsp. pallidum was found to proceed slowly. Heat-killed T. pallidum subsp. pallidum were susceptible to opsonization with 2% immune serum, whereas live treponemes were resistant to this concentration of antibody. High concentrations of immune serum were found to increase phagocytosis of the spirochetes. Live T. pallidum subsp. pallidum had bound limited quantities of immunoglobulin G in vivo, and only opsonization with 20% immune serum resulted in a detectable increase in surface-bound immunoglobulin in vitro. Kinetic studies suggested a steady rate of phagocytosis that is considerably slower than with other bacteria. Scanning electron microscopy studies of the phagocytizing macrophages showed that the treponemes were detached from the membrane filters and scooped onto the ruffled portion of the macrophage surface. This lengthy physical process, along with the lack of a dramatic increase in ingestion after opsonization, may account for the slow rate of phagocytosis.     

Lymphocyte Transformation in Syphilis: an In Vitro Correlate of Immune Suppression In Vivo?

Suppression of cellular immunity during primary and secondary infection may explain, in part, the unusual clinical evolution of syphilis. We have previously shown that lymphocytes from normal subjects undergo blastic transformation when exposed in vitro to Treponema refringens. This response was suppressed in patients with syphilis. the suppression being unrelated to serum factors. In the present paper we studied lymphocyte response in vitro to T. refringens, T. reiter, and T. pallidum as well as to monilia and trychophytins. The response to these antigens was suppressed in patients with syphilis although the response to phytohemagglutinin. pokeweed mitogen, and streptolysin was normal. These data support the hypothesis that human infection with T. pallidum is followed by a complex interaction between cellular and humoral immunity, the former being suppressed in primary and secondary stages.