Use of monoclonal antibodies to identify cerebrospinal fluid lymphoblasts in children with acute lymphoblastic leukemia

The identification of small numbers of leukemic cells in the cerebrospinal fluid (CSF) presents a diagnostic problem in the treatment of children with acute lymphoblastic leukemia (ALL). We adapted a latex sphere rosetting technique to allow us to identify simultaneously cell surface markers and cell morphology in 199 CSF samples from 34 patients and 14 control subjects. In patients without leukemic meningitis, the majority of CSF lymphocytes (69%) were found to be mature T cells positive for OKT11. A much smaller number of cells (8%) were found to be B cells positive for la. In these children, only 3% of CSF lymphoid cells expressed the common acute lymphoblastic leukemia antigen (CALLA). Similar results were found in the control subjects. By contrast, 28 CSF samples from nine children with varying numbers of CSF lymphoblasts had much greater proportions of CALLA- and la-positive CSF cells (24% to 96%). Leukemic meningitis was present in one of these patients and later developed in four others. However, three patients with small numbers of lymphoblasts present but with low proportions of CALLA-positive CSF cells (less than 5%) subsequently had normal CSF examinations. We found the use of this rosetting technique valuable in providing information complementary to that obtained from cell morphology alone about the possible malignant nature of small numbers of lymphoblast-like CSF cells seen on cytocentrifuge preparations in children with ALL.     

The activation of the contact phase of coagulation by physiologic surfaces in plasma: the effect of large negatively charged liposomal vesicles

The endogenous, negatively charged surface that induces activation of the contact coagulation factors was investigated in plasmas taken from women in late pregnancy and control subjects of child-bearing age. The plasmas from the two groups of subjects were incubated at 4 degrees C for 24 hours either in plastic or in glass tubes and the factor VII coagulant activity (VIIc) was assayed in the treated plasmas. The activation of factor VII under these conditions involves the generation of enzymes derived from factor XII (XIIa). The contact surface is rate- limiting for the activation of factor VII in the plasmas in both groups of subjects and can be supplemented by large multilamellar liposomal vesicles carrying the appropriate density of negative charge. The size of these vesicles is within the range of sizes of the large lipoprotein particles (chylomicrons, very low and intermediate-density lipoproteins). The relationship between the density of negative charge on the liposomal vesicles and VIIc was similar in the late pregnancy and the control plasmas incubated in plastic tubes. At a saturating density of negative charge the observed relative VIIc was similar in both sets of plasmas. The incubation of late pregnancy or control plasma in plastic tubes in the presence of sodium stearate caused VIIc to increase with increasing concentration of the added fatty acid. These results suggest that large lipoprotein particles carrying the appropriate free fatty acid at a sufficient density of negative charge could provide the contact surface that induces the generation of factor XIIa and the subsequent activation of factor VII. Moreover, plasmas from women in late pregnancy have a higher concentration of potential surface and a higher density of negative charge than the plasmas from nonpregnant women.     

Hepatitis B infection in a non-drug abusing prostitute population in Mexico

The prevalence and risk factors of hepatitis B infection were studied in 354 non-drug abusing female prostitutes and 360 female controls in Tijuana, Mexico. Hepatitis B surface antigen (HBsAg) was found in the same percentage (0.8%) of prostitutes and controls. In contrast, antibody markers (anti-HBs or anti-HBc) were found in a significantly higher percentage of prostitutes than controls (8.2% vs. 2.2%, p = 0.0006). Prostitutes also had a higher prevalence of a positive RPR/FTA-ABS test for syphilis (p less than 0.0001). There was a significant association between the presence of hepatitis B markers and positive syphilis serology and a history of having had a STD. In this non-drug abusing population, prostitution was found to be a risk factor for total hepatitis B infection but not for surface antigenemia. Further studies are indicated to determine the incidence of chronic infection in adult women following sexual transmission of hepatitis B.     

Sunflower (Helianthus annuus L.) as a pre-Columbian domesticate in Mexico

Mexico has long been recognized as one of the world's cradles of domestication with evidence for squash (Cucurbita pepo) cultivation appearing as early as 8,000 cal B.C. followed by many other plants, such as maize (Zea mays), peppers (Capsicum annuum), common beans (Phaseolus vulgaris), and cotton (Gossypium hirsutum). We present archaeological, linguistic, ethnographic, and ethnohistoric data demonstrating that sunflower (Helianthus annuus) had entered the repertoire of Mexican domesticates by ca. 2600 cal B.C., that its cultivation was widespread in Mexico and extended as far south as El Salvador by the first millennium B.C., that it was well known to the Aztecs, and that it is still in use by traditional Mesoamerican cultures today. The sunflower's association with indigenous solar religion and warfare in Mexico may have led to its suppression after the Spanish Conquest. The discovery of ancient sunflower in Mexico refines our knowledge of domesticated Mesoamerican plants and adds complexity to our understanding of cultural evolution.     

Impact of platelet transfusions in children with post-diarrheal hemolytic uremic syndrome

Background

Platelet transfusions should be avoided in children with post-diarrheal hemolytic uremic syndrome (D + HUS) because they might increase microthrombi formation, thereby aggravating the disease. As this possibility has not yet been explored, we investigated whether platelet transfusion in patients with D + HUS would lead to a worse disease course compared to that in patients who did not receive platelet transfusion.

Methods

This was a case–control study in which data from D + HUS children who received platelet transfusions (cases, n? = ?23) and those who did not (controls, n? = ?54) were retrospectively reviewed and compared.

Results

Both patient groups were similar in age (p?=?0.3), gender (p? =? 0.53), weight (p? = ?0.86), height (p? = ?0.45), prior use of non-steroidal anti-inflammatory drugs (p? = ?0.59) or antibiotics (p ?= ?0.45) and presence of dehydration at admission (p? = ?0.79). The two groups also did not differ in initial leukocyte count (p? = ?0.98), hematocrit (p? = ?0.44) and sodium (p? = ?0.11) and alanine aminotransferase levels (p? = ?0.11). During hospitalization, dialysis duration (p? = ?0.08), number of erythrocyte transfusions (p? =? 0.2), serum creatinine peak (p? = ?0.22), presence of severe bowel (p? = ?0.43) or neurologic (p? = ?0.97) injury, arterial hypertension (p? = ?0.71), need for intensive care (p? = ?0.33) and death (p? = ?1.00) were also comparable.

Conclusion

Our findings suggest that platelet transfusion does not aggravate the course of the disease. Conversely, no hemorrhagic complications were observed in the group of patients who did not receive a platelet transfusion. Until these observations are confirmed by further studies, the benefits and risk of platelet transfusion should be thoughtfully balanced on an individual case basis.