Recombinant human thrombopoietin in combination with granulocyte colony-stimulating factor enhances mobilization of peripheral blood progenitor cells, increases peripheral blood platelet concentration, and accelerates hematopoietic recovery following high-dose chemotherapy

Lineage-specific growth factors mobilize peripheral blood progenitor cells (PBPC) and accelerate hematopoietic recovery after high-dose chemotherapy. Recombinant human thrombopoietin (rhTPO) may further increase the progenitor-cell content and regenerating potential of PBPC products. We evaluated the safety and activity of rhTPO as a PBPC mobilizer in combination with granulocyte colony-stimulating factor (G-CSF) in 29 breast cancer patients treated with high-dose chemotherapy followed by PBPC reinfusion. Initially, patients received escalating single doses of rhTPO intravenously (IV) at 0.6, 1.2, or 2.4 micrograms/kg, on day 1. Subsequent patients received rhTPO 0.6 or 0.3 micrograms/kg on days -3, -1, and 1, or 0.6 micrograms/kg on days -1 and 1. G-CSF, 5 micrograms/kg IV or subcutaneously (SC) twice daily, was started on day 3 and continued through aphereses. Twenty comparable, concurrently and identically treated patients (who were eligible and would have been treated on protocol but for the lack of study opening) mobilized with G-CSF alone served as comparisons. CD34(+) cell yields were substantially higher with the first apheresis following rhTPO and G-CSF versus G-CSF alone: 4.1 x 10(6)/kg (range, 1.3 to 17.6) versus 0.8 x 10(6)/ kg (range, 0.3 to 4.2), P =.0003. The targeted minimum yield of 3 x 10(6) CD34(+) cells/kg was procured following a single apheresis procedure in 61% of the rhTPO and G-CSF-mobilized group versus 10% of G-CSF-mobilized patients (P =.001). In rhTPO and G-CSF mobilized patients, granulocyte (day 8 v 9, P =.0001) and platelet recovery (day 9 v 10, P =.07) were accelerated, and fewer erythrocyte (3 v 4, P =.02) and platelet (4 v 5, P =.02) transfusions were needed compared with G-CSF-mobilized patients. Peripheral blood platelet counts, following rhTPO and G-CSF, were increased by greater than 100% and the platelet content of PBPC products by 60% to 110% on the first and second days of aphereses (P <.0001) with the greatest effect seen with repeated dosing of rhTPO at 0.6 microgram/kg. rhTPO is safe and well tolerated as a mobilizing agent before PBPC collection. Mobilization with rhTPO and G-CSF, in comparison to a comparable, nonrandomized G-CSF-mobilized group of patients, decreases the number of apheresis procedures required, may accelerate hematopoietic recovery, and may reduce the number of transfusions required following high-dose chemotherapy for breast cancer.

Widespread outbreaks of measles in rural Uttar Pradesh, India, 1996: high risk areas and groups

OBJECTIVE

To describe outbreaks of measles which affected many districts in Uttar Pradesh (UP) during 1996.

DESIGN

Outbreak investigations.

SETTING

The state of Uttar Pradesh, India.

METHODS

The reported data on measles morbidity, mortality and vaccine coverage from 1991 through 1996 were reviewed. Reported vaccine coverage levels were compared with the results of coverage surveys carried out in UP from 1992 through 1996. Line lists on measles cases were analyzed to ascertain the age, immunization status, geographical distribution, and age and sex-specific fatality ratios during the outbreaks. A community survey was organized in 7 affected villages to estimate vaccine effectiveness.

RESULTS

Fifty one of 68 districts in UP reported 6922 measles cases and 281 deaths in 1996. The majority of cases and deaths occurred in June and July which are usually low transmission months. Overall cases fatality ratio (CFR) was 4.1%. CFRs were significantly higher in females and young children. The median age of cases was found to be below 5 years. There was heavy clustering of cases and deaths in rural areas. About 85% of the cases and virtually all the measles associated deaths occurred in unvaccinated children. Published documents on statewide coverage surveys revealed that the measles vaccine coverage levels ranged between 26% and 36% during 1992-96. Large gaps were found between reported coverage and survey results. Nevertheless, epidemiological studies indicated a vaccine effectiveness of more than 90%.

CONCLUSIONS

The outbreaks occurred due to poor vaccine coverage levels and an inefficient surveillance system which failed to generate early warning signals. The study highlights the urgent need to raise the vaccine coverage levels rapidly in all districts to achieve measles control and prevent future outbreaks in UP.

Chest wall pain and possible rhabdomyolysis after chloropicrin exposure. A case series

Three cases are summarized in which persistent chest wall pain, as well as elevations of creatine phosphokinase (CK) levels, occurred after exposure to chloropicrin vapor in an agricultural chemicals facility. Both the severity of the symptoms and the degree of biochemical abnormality appeared to follow a dose-response relationship. Myoglobinuria, on the other hand, was not found. Elevation of CK after chloropicrin exposure has not previously been reported and may represent low-grade rhabdomyolysis. Workups performed after symptomatic chloropicrine exposure should include CK-level determination.

Epidemiologic consequences of moderate coverage levels of measles vaccine in a district headquarter town (Alwar) in India, 1996

This paper describes the epidemiology of measles in a medium size town (population 240,000) in India where vaccine coverage levels have remained constant at around 70 per cent in the past 7 years. A retrospective community survey covering 4023 children under 10 years old detected 252 cases of measles in the previous year. This gave an annual incidence of 6.3 per cent (95 per cent CI 5.5-7). About half of the cases occurred in vaccinated children. Only 5 per cent of the cases occurred in children below 9 months of age. This age is appropriate for routine measles immunization. Despite modest coverage levels with only 54 per cent effective vaccine (estimated by a screening method), there was a modest upward shift in the age distribution of measles cases; the median age was more than 48 months.

Transplacental transfer of measles antibody in Delhi

OBJECTIVE

To find out the patterns of and the factors, if any, affecting the transplacental transfer of measles antibody.

DESIGN

Comparison of measles antibody titres in mothers with titres in cord blood samples.

METHODS

Maternal and cord blood samples from 174 full-term pregnant women of middle socio-economic status were tested for hemagglutination inhibition (HI) antibody against measles in Delhi during October 1993 to January 1995. None of the mothers had been immunized against measles.

RESULTS

Antibody were undetectable in both maternal and cord samples in only 4 (2.3%) pairs. Mean maternal titre was found to be 2.94 Log2. Transplacental concentration and dilution were respectively observed in 34% and 26% of the samples. Cord titres were more often higher than the maternal values only if the maternal values were low. Overall, cord/maternal ratio of mean titre (Log2) was found to be 1.06. Although the age of the mother and parity had had no significant bearing on the transplacental transfer of measles antibody, cord titres were significantly more often higher than the maternal values as the birth weight increased (Chi-square for linear trend = 5.4; p = 0.02).

CONCLUSIONS

The study failed to show appreciable concentration of measles antibodies across the placenta.

Tyrphostin AG957, a tyrosine kinase inhibitor with anti-BCR/ABL tyrosine kinase activity restores beta1 integrin-mediated adhesion and inhibitory signaling in chronic myelogenous leukemia hematopoietic progenitors

Abnormal beta1 integrin receptor function may contribute to the continuous proliferation and abnormal circulation of malignant hematopoietic progenitors in chronic myelogenous leukemia (CML). Previous studies suggest that abnormal integrin function in CML progenitors is related to the presence of the BCR/ABL oncogene. BCR/ABL may alter integrin function in CML by phosphorylating cytoskeletal and/or signaling proteins important for normal integrin function. We evaluated the effect of Tyrphostin AG957, a protein tyrosine kinase (PTK) inhibitor which has activity against the p210BCR/ABL kinase, on beta1 integrin function in CML progenitors. Incubation of CML marrow CD34+HLA-DR+ cells with Tyrphostin AG957 at concentrations that did not affect colony-forming cells (CFC) viability, but which partly inhibited p210BCR/ABL kinase activity, significantly increased CML CFC adhesion to stroma and alpha4beta1 and alpha5beta1 integrin binding fragments of fibronectin (FN). CML CFC proliferation, unlike that of normal CFC, is not inhibited following integrin receptor engagement with FN or anti-integrin antibodies. AG957 did not alter CML CFC proliferation by itself, but resulted in significant inhibition of CML CFC proliferation following integrin engagement. Another PTK inhibitor, Tyrphostin AG555, which does not have anti-p210BCR/ABL kinase activity, did not affect CML CFC adhesion or proliferation. Neither AG957 nor AG555 affected normal CFC adhesion or proliferation. In BCR/ABL expressing cells, AG957 partially inhibited phosphorylation of several proteins that are BCR/ABL PTK substrates and are involved in normal integrin signaling. These studies suggest that abnormal tyrosine phosphorylation may play an important role in defective integrin function in CML progenitors.

Comparative analysis of autografting in chronic myelogenous leukemia: effects of priming regimen and marrow or blood origin of stem cells

The aims of this study were (1) to evaluate the effect of intermediate (cyclophosphamide alone) or intensive (mitoxantrone, cytosine arabinoside, cyclophosphamide) priming on the cytogenetic response in mobilized bone marrow (BM) or peripheral blood (PB) progenitors in patients with chronic myelogenous leukemia (CML), (2) to determine the incidence of cytogenetic remissions after mobilized progenitor transplantation in CML, and (3) to determine the effect of in vivo priming on the ability to select Philadelphia chromosome-negative (Ph-negative) CD34(+)HLA-DR- cells from mobilized BM or PB in quantities sufficient for transplantation. Between February 1994 and March 1997, 44 patients were enrolled in three sequential protocols. Although the duration of neutropenia after only cyclophosphamide mobilization was shorter, clinical morbidity for the intermediate and intensive priming protocols was similar. Cytogenetic responses in mobilized PB progenitors were similar after mobilization with either intermediate or intensive chemotherapy. The degree of Ph negativity in the mobilized product correlated with disease stage at the time of mobilization (early chronic phase [ECP] > late CP > accelerated phase). Cytogenetic responses after transplantation with mobilized progenitors obtained after the different regimens were similar. The cytogenetic status of the graft predicted the cytogenetic status of marrow obtained 3 weeks after transplantation whereas cytogenetic responses 3, 6, and 12 months after transplantation correlated with the number of BCR/ABL-negative CD34(+)HLA-DR- cells, but not the number of Ph-negative metaphases in the graft. In patients with ECP CML, mobilized PB collections yielded significantly more CD34(+)HLA-DR- cells than from steady state or mobilized BM. CD34(+)HLA-DR- cells were Ph negative and polyclonal (X-chromosome inactivation) in the majority of ECP CML patients, before and after mobilization and irrespective of the mobilization regimen. Because infusion of large numbers of Ph-negative CD34(+)HLA-DR- cells predicted superior outcome after transplantation, approaches in which CD34(+)HLA-DR- cells are selected from mobilized PB may result in longer lasting and clinically significant cytogenetic responses after transplantation.

Serological diagnosis of childhood tuberculosis by estimation of mycobacterial antigen 60-specific immunoglobulins in the serum

SETTING

An ELISA assay based on mycobacterial antigen 60 (A60) for the estimation of specific immunoglobulins in the serum has been used successfully for the rapid diagnosis of tuberculosis in studies done predominantly in Western countries. In a recent Indian study, encouraging results were reported in adult tuberculosis.

OBJECTIVE

To evaluate the utility of this ELISA test for rapid diagnosis of different clinical forms of tuberculosis in Indian children.

DESIGN

ELISA test based on mycobacterial A60 was used to estimate specific IgM, IgA and IgG antibodies in the sera obtained from 452 cases of tuberculosis and 161 controls in the paediatric population of Delhi, India.

RESULTS

Of the 161 controls, only 7.4% were positive for IgM, 4.3% for IgG, 3.7% for IgA and 8% when a combination of IgM and IgA was considered. Of 58 cases of definite pulmonary tuberculosis, 55.2% were positive for IgM, 32.7% for IgG, 36.2% for IgA and a high positivity of 72.4% was seen when IgA and IgM estimations were combined. The corresponding figures in 150 cases of definite extrapulmonary tuberculosis were 57.3%, 36.6%, 38% and 76.6%. A relatively weak serology was observed in 244 cases of probable tuberculosis. A very high positivity (95%) was seen in acid-fast bacilli-positive cases of tuberculosis.

CONCLUSIONS

Our findings point to a very good specificity (92%) and a reasonably good sensitivity (75.5%) of the test when combined IgM and IgA antibody titres are considered in the diagnosis of childhood tuberculosis.

Cloning and sequencing of the cDNA for an RNA-binding protein from the Mexican axolotl: binding affinity of the in vitro synthesized protein

A full length cDNA for an RNA-binding protein (axolotl RBP) with consensus sequence (RNP-CS) from the Mexican axolotl, Ambystoma mexicanum, has been cloned from a subtraction library. In vitro translation with synthetic mRNA and subsequent hybrid-arrested translation with a specific antisense oligonucleotide confirms that the axolotl RBP cDNA encodes an approx. 16 kDa polypeptide. Computer-assisted analyses revealed amino acid similarities of 58-60% to various RNA-binding proteins and a 90 amino acid region at the amino-terminal end constituting the putative RNA-binding domain (RNP-CS) with two highly conserved motifs, RNP2 and RNP1. Phylogenetic analysis suggests that the putative RNA-binding protein from axolotl is unique. A binding assay with radiolabeled axolotl RBP showed that this RNA-binding protein bound strongly with poly(A) and to a lesser degree with poly(U), but not at all with poly(G), poly(C), or DNA.

Endemic cholera in Delhi, 1995: analysis of data from a sentinel centre

Data on cholera cases admitted to the Delhi Infectious Diseases Hospital (IDH) are presented to describe the pattern of occurrence of cholera in Delhi in 1995. Rectal swabs from 4082 cases of acute diarrhoea admitted to the IDH were examined for excretion of Vibrio cholerae. Of them, 2004(49%) and 4(0.1%) were positive for V. cholerae O1 biotype El Tor and V. cholerae O139 respectively. Most cholera cases occurred during May-September (summer and monsoon months). The period from January to March (winter) was completely free from cholera. The urban areas were not affected uniformly. Of the 80 PIN (Postal Index Number) code areas, 10 contributed to 57% of the cases. The early cases were scattered in PIN code areas distant from one another. The hospitalisation rates for cholera were the highest in children aged less than five years and declined significantly with increasing patients' age. Males had significantly higher rates than females aged up to 20 years, whereas the situation was reversed in the 20 to 39 year age group. Four per cent of the affected families had multiple cases. An estimated 1% of the household contacts of hospitalised cases of cholera were themselves hospitalised for cholera within 2 days of the first admission. Of the 260 V. cholerae O1 isolates tested, 4%, 7%, 8%, 89%, 91% and 95% were resistant to tetracycline, nalidixic acid, chloramphenicol, co-trimoxazole, streptomycin, and furazolidone respectively. The study highlights the usefulness of surveillance data to identify groups, urban areas and seasons with increased risk for cholera and to allow control measures to be focussed on those in greatest need.

Inhibition of BCR-ABL expression with antisense oligodeoxynucleotides restores beta1 integrin-mediated adhesion and proliferation inhibition in chronic myelogenous leukemia hematopoietic progenitors

Chronic myelogenous leukemia (CML) is characterized by the continuous proliferation and abnormal circulation of malignant hematopoietic progenitors. This may be related to the unresponsiveness of CML progenitors to beta1 integrin adhesion receptor-mediated inhibition of progenitor proliferation by the marrow microenvironment. In hematopoietic cell lines, the BCR-ABL oncogene product, p210(BCR-ABL), interacts with a variety of cytoskeletal elements important for normal integrin signaling. We studied the role of p210(BCR-ABL) in abnormal integrin function in CML by evaluating the effect of inhibition of BCR-ABL expression with antisense oligodeoxynucleotides (AS-ODNs) on integrin-mediated adhesion and proliferation inhibition of malignant primary progenitors from CML marrow. Preincubation of CML CD34(+)HLA-DR+ (DR+) cells with breakpoint-specific AS-ODNs significantly increased adhesion of CML progenitors to stroma and fibronectin (FN). Pretreatment with breakpoint-specific ODNs also resulted in significant inhibition of CML progenitor proliferation after ligand or antibody-mediated beta1 integrin engagement. Breakpoint-specific ODNs were significantly more effective in restoring CML progenitor adhesion and proliferation inhibition than control ODNs. BCR-ABL mRNA and p210(BCR-ABL) levels in CML CD34(+) cells were significantly reduced after incubation with breakpoint-specific AS-ODN. These studies indicate a role for BCR-ABL in abnormal circulation and defective integrin-dependent microenvironmental regulation of proliferation of CML hematopoietic progenitors.

The heart of metamorphosing Mexican axolotl but not that of the cardiac mutant is associated with the upregulation of Hox A5

The Mexican axolotl (Ambystoma mexicanum) is a facultative neotene which rarely undergoes metamorphosis in the wild. We now report for the first time a dramatic increase in the expression of HoxA5 in axolotl hearts as determined by RT-PCR and in situ hybridization analyses during spontaneous metamorphosis. The Mexican axolotl has a naturally occurring mutation called gene c which allows hearts in homozygous (c/c) embryos to form but never to beat. RT-PCR analysis has not shown any significant differences of HoxA5 expression in normal and mutant hearts. The predicted open reading frame of our already published partial cDNA clone of HoxA5 was confirmed by expressing it as a fusion protein with Glutathione transferase (GST fusion protein). Phylogenetic analysis with the deduced amino acid sequence of the isolated cDNA of the axolotl homolog of the murine HoxA5 shows that the axolotl sequence clusters more closely with the human and mouse HoxA5 homologs than with axolotl sequence. Western blot analysis revealed that anti-mouse HoxA5 antibody recognizes the axolotl HoxA5 protein.

Prevalence of North India of hepatitis B carrier state amongst pregnant women

The study was undertaken to determine the hepatitis B carrier rate in North India along with the relative infectivity of the carriers. A total of 1,112 pregnant women were investigated for hepatitis B carrier state during their routine visits to antenatal clinics. All three tiers of the health care delivery system were included from four regions of North India. The sera were screened for the presence of hepatitis B surface antigen (HBsAg), hepatitis B "e" antigen (HBeAg), and antibody to hepatitis B "e" antigen (Anti-HBe) by third generation Macro ELISA tests. The average hepatitis B surface antigen carrier rate was 9.5%. The carriers were found to be of relatively low infectivity with HBeAg and Anti-HBe present in 12.0% and 25.3% of the HBsAg carriers respectively, and both these markers absent in 62.7%. It was concluded that in the past decade the hepatitis B endemicity in North India has probably increased, but the relative infectivity of the carriers remains the same.

Interferon-alpha restores beta1-integrin-dependent, collagen-mediated platelet aggregation in a patient with chronic myelogenous leukemia

Although interferon-alpha (IFN-alpha) induces hematologic remissions in 70% to 80% of patients with chronic myelogenous leukemia (CML) and complete or near-complete cytogenetic remissions in 10% to 20% of patients, the exact mechanisms underlying these clinical results remain unclear. We have hypothesized that IFN-alpha acts at least in part through restoration of beta1-integrin function on malignant hematopoietic progenitors that can promote adhesion of malignant progenitors to the marrow microenvironment. This may then restore microenvironmental inhibition of progenitor proliferation and induce tumor dormancy. We demonstrate that IFN-alpha administration to a patient suffering from a clinically severe bleeding diathesis reversed the defective collagen-mediated aggregation of platelets expressing normal numbers of functionally inactive collagen receptors. This is the first in vivo demonstration that IFN-alpha can up-regulate the function of adhesion receptors in CML and supports the premise that IFN-alpha induces remissions by restoring normal integrin-mediated interactions between progenitors and microenvironmental components.

Autologous transplantation for the treatment of chronic myelogenous leukemia

There is evidence that benign, Ph-negative hematopoietic progenitors persist in the marrow and blood of some patients with chronic myelogenous leukemia (CML). A number of pilot studies using purged and unpurged marrow or peripheral blood autografts have demonstrated that autologous transplantation can result in transient cytogenetic responses in CML. Although not curative, this procedure may be associated with longer-than-expected patient survival and represents an alternative treatment for patients ineligible for allogeneic transplantation and not responding to interferon-alpha therapy. Several novel approaches are being developed to improve graft purging and eliminate residual leukemia post-transplantation. Such approaches may allow for long-term restoration of Ph-negative hematopoiesis following the procedure.

The effect of interferon-alpha on beta-1 integrin mediated adhesion and growth regulation in chronic myelogenous leukemia

There is considerable interest in understanding the mechanisms by which interferon-alpha can induce hematological and cytogenetic remissions and prolong survival in patients with chronic myelogenous leukemia (CML). There is evidence that the selective expansion and growth advantage of malignant hematopoietic progenitors in CML may be related, at least in part, to their deficient responsiveness to normal negative regulation by the marrow stromal microenvironment and that interferon-alpha may restore normal hematopoiesis in CML by restoring normal microenvironmental regulation of malignant CML progenitor proliferation. In normal hematopoiesis, beta1 integrin receptors mediate progenitor adhesion to stroma. Stimulation of beta1 integrin receptors on normal progenitors results in transmission of proliferation inhibitory signals. CML progenitors demonstrate defective beta1 integrin receptor-mediated adhesion and regulation of proliferation. We have shown that interferon-alpha can restore both beta1 integrin mediated adhesion as well as integrin-mediated proliferation inhibition of CML progenitors. Interferon-alpha enhances CML integrin function through direct effects on CML progenitors as well as indirect effects on stroma. Restored beta1 integrin-mediated regulation of malignant CML progenitor proliferation may result in restoration of normal hematopoiesis in CML patients treated with interferon-alpha. There is evidence that abnormal integrin mediated signaling in CML progenitors may result from abnormalities in integrin-cytoskeletal interactions induced by the p210BCR/ABL tyrosine kinase. Although the exact mechanisms by which interferon-alpha restores normal integrin signaling in CML are not known, preliminary studies indicate that this may at least partly be related to the restoration of normal integrin-cytoskeletal interactions. The above studies offer some insights into the mechanisms of abnormal hematopoietic regulation in CML and the mechanisms by which interferon-alpha may restore normal hematopoiesis, in this disease.

Outbreak of viral hepatitis B in a rural community in India linked to inadequately sterilized needles and syringes

In India, virtually all outbreaks of viral hepatitis are considered to be due to faeco-orally transmitted hepatitis E virus. Recently, a cluster of 15 cases of viral hepatitis B was found in three villages in Gujarat State. The cases were epidemiologically linked to the use of inadequately sterilized needles and syringes by a local unqualified medical practitioner. The outbreak evolved slowly over a period of 3 months and was marked by a high case fatality rate (46.7%), probably because of concurrent infection with hepatitis D virus (HDV) or sexually transmitted infections. But for the many fatalities within 2-3 weeks of the onset of illness, the outbreak would have gone unnoticed. The findings emphasize the importance of inadequately sterilized needles and syringes in the transmission of viral hepatitis B in India, the need to strengthen the routine surveillance system, and to organize an education campaign targeting all health care workers including private practitioners, especially those working in rural areas, as well as the public at large, to take all possible measures to prevent this often fatal infection.

Diesel exhaust exposure and lung cancer

We evaluated the relation between occupational exposure to diesel exhaust and cancer of the lung in a meta-analysis of 29 published cohort and case-control studies. Twenty-one of the 23 studies meeting the inclusion criteria had observed relative risk estimates greater than one. Pooled effect measures weighted by study precision indicated an increased relative risk (RR) for lung cancer from occupational exposure to diesel exhaust [RR = 1.33; 95% confidence interval (CI) = 1.24-1.44]. Subanalysis of case-control (RR = 1.33; 95% CI = 1.18-1.51) vs cohort studies (RR = 1.33; 95% CI = 1.21-1.47) and of studies that controlled for smoking (RR = 1.35; 95% CI = 1.20-1.52) vs those that did not (RR = 1.33; 95% CI = 1.20-1.47) produced results that did not differ from those of the overall analysis. On the other hand, cohort studies using internal comparisons (RR = 1.43; 95% CI = 1.29-1.58) showed higher relative risks than those using external comparisons (RR = 1.22; 95% CI = 1.04-1.44). Heterogeneity between studies was reduced when we stratified studies by the occupational setting in which exposure occurred. A positive duration-response relation was evident in those studies that were stratified by employment duration. This meta-analysis supports a causal association between increased risks for lung cancer and exposure to diesel exhaust.

A clinically suitable ex vivo expansion culture system for LTC-IC and CFC using stroma-conditioned medium

FACS-selected CD34+ HLA-DR- cells (DR- cells) may provide a source of benign stem cells suitable for autografting in chronic myelogenous leukemia (CML) and other hematological malignancies. However, DR- cell selection depletes the majority of committed hematopoietic progenitors, which may be important for early engraftment. Furthermore, only a small number of DR- cells may be selectable in certain patients. These impediments to the use of DR- cells for autografting may be overcome through the development of ex vivo culture systems that support expansion and initial differentiation of primitive progenitors. Because 2-week culture of DR- cells in a stroma "noncontact" system supplemented with interleukin-3 (IL-3) and macrophage inflammatory protein 1-alpha (MIP-1alpha) expands both long-term culture-initiating cells (LTC-ICs) and colony-forming cells (CFCs), we adapted this system to a clinically applicable method for expanding LTC-ICs and CFCs ex vivo. In initial small-scale studies, DR cells were grown in stroma conditioned medium (SCM) supplemented with IL-3 with or without additional growth-promoting cytokines and the chemokines PF-4 and BB10010, all approved for clinical use. An IL-3 dose-dependent expansion of committed progenitors and LTC-ICs was observed when DR- cells were cultured in tissue culture plates in SCM+IL-3 for 2 weeks. Similar CFC expansion along with increased (5-fold) LTC-IC expansion was observed following addition of PF-4 to SCM+IL-3 cultures. The addition of stem cell factor (SCF), but not of IL-6, IL-11, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage (GM)-CSF, IL-1, and IL-7, increased CFC and LTC-IC expansion beyond the levels observed with SCM+IL-3 alone. We next evaluated the suitability of this culture system for scale-up. Culture of 2-6 x 10(5) DR- cells in gas-permeable bags with SCM+IL-3 resulted in similar CFC and LTC-IC expansion as seen in small-scale cultures. In addition, we observed that progenitors capable of differentiating to natural killer (NK)-cells were maintained under these conditions. Finally, we found that BCR/ABL mRNA-negative CFCs and LTC-ICs present in DR- cells selected from steady-state CML marrow could be expanded in large-scale SCM+IL-3 cultures. We conclude that culture of DR- cells for 2 weeks in SCM+IL-3 culture, with or without PF-4 or SCF, results in significant CFC and LTC-IC expansion and lymphoid NK progenitor maintenance. This culture system is readily adaptable to the expansion of primitive progenitors for autotransplantation.

Pathophysiology of CML: do defects in integrin function contribute to the premature circulation and massive expansion of the BCR/ABL positive clone?

Hematopoiesis takes place in close contact with the marrow microenvironment. Normal progenitors adhere through a variety of receptors to stroma and extracellular matrix components, including fibronectin. Adhesion through beta1-integrin receptors to fibronectin not only anchor progenitors to the stroma but also result in direct adhesion-mediated signaling that inhibits progenitor proliferation. In contrast to normal hematopoiesis, chronic myelogenous leukemia (CML) is characterized not only by abnormal, premature circulation of primitive progenitors in the blood but also by continuous progenitor proliferation. Although CML progenitors express the same integrin receptors as normal progenitors, they fail to adhere to stroma and fibronectin, suggesting structural or functional abnormalities of these receptors. Furthermore, CML cells present in contact with stroma or fibronectin continue to proliferate, suggesting that failure to adhere through integrin receptors may also underlie the abnormal proliferation of CML progenitors. The observation that integrin-mediated adhesion and proliferation-inhibitory signaling can be restored through treatment with interferon-alpha or an activating anti-beta1-integrin antibody suggests a functional rather than structural defect that may be related to the presence of the BCR/ABL gene rearrangement in these cells. Insights into the role of integrins as adhesion molecules but also receptors that instruct hematopoietic progenitors to survive, proliferate, and possibly differentiate will not only further our understanding of the normal hematopoietic process but also provide insights into diseases characterized by deranged adhesion and proliferation that may lead to novel therapeutic approaches.

Integrin-mediated regulation of hematopoiesis: do BCR/ABL-induced defects in integrin function underlie the abnormal circulation and proliferation of CML progenitors?

Hematopoiesis takes place in close contact with the marrow microenvironment. Normal progenitors adhere through a variety of receptors to stroma and extracellular matrix components, including fibronectin. Adhesion through integrins to fibronectin may not only serve to anchor progenitors to the microenvironment but also to directly alter the proliferative behavior of normal hematopoietic progenitors. Chronic myelogenous leukemia (CML) is a malignant disease of the hematopoietic stem cell. At the molecular level, CML is characterized by the BCR/ABL gene rearrangement which encodes for the oncoprotein, p210bcr-abl. Presence of the p210bcr-abl tyrosine kinase is necessary and sufficient for the malignant transformation of hematopoietic cells. Clinically, CML is characterized by an abnormal, premature release of primitive progenitors and precursors in the blood and by the continuous proliferation of the malignant progenitor population. In vitro, CML progenitors fail to adhere to or be regulated by marrow stroma. Since CML progenitors express similar numbers of integrin adhesion receptors as normal progenitors, functional rather than quantitative differences of these receptors on CML progenitors may be responsible for the abnormal circulation and proliferation of the malignant clone. In this manuscript we will review the role of integrin adhesion receptors present on normal hematopoietic progenitors in the regulation of their proliferation and discuss signal transduction mechanisms that may be responsible for these effects. We will also discuss the integrin defect in CML which may be caused by the presence of the oncoprotein, P210bcr-abl, and may explain the abnormal trafficking and proliferation observed in CML.

A specific synthetic RNA promotes cardiac myofibrillogenesis in the Mexican axolotl

Ambystoma mexicanum is an intriguing animal model for studying heart development because it carries a mutation in gene c. Hearts of homozygous recessive (c/c) mutant embryos do not contain organized myofibrils and fail to beat. However, the defect can be corrected by organ-culturing the mutant heart in the presence of RNA from anterior endoderm or RNA from endoderm mesoderm-conditioned medium. We constructed a cDNA library from total conditioned medium RNA in a pcDNAII expression vector. We screened the cDNA library by an organ culture bioassay and isolated a single clone (Cl#4), the synthetic RNA from which corrects the heart defect by promoting myofibrillogenesis. The insert size of the active clone is 166 nt in length with a unique nucleotide sequence. The anti-sense RNA from Cl#4 using SP6 RNA polymerase failed to rescue mutant hearts. The ability of this small RNA to correct the mutant heart defect suggests that the RNA probably does not act as an mRNA. While the precise mechanism of action is not yet known, on the basis of our studies to date it is very clear that the sense strand of Cl#4 RNA has the ability to promote myofibrillogenesis and rescue the mutant hearts both in vitro and in vivo.

Evidence of cortical metabolic dysfunction in early Huntington's disease by single-photon-emission computed tomography

We compared perfusion of prefrontal, motor, and sensory cortices and basal ganglia in 29 Huntington's disease (HD) patients and nine controls. We found a significant reduction in perfusion in patients with HD of short (< 6 years, n = 10), medium (6-10 years, n = 8), and long duration (> 10 years, n = 11) compared with controls. Among short-duration patients, we observed decreases in cortical perfusion before evidence of atrophy on magnetic resonance imaging, suggesting that decreases in neuronal activity, as reflected by perfusion levels, precede gross structural changes. As expected, decreased perfusion was marked in basal ganglia. The extent of cortical perfusion correlated with clinical assessments of functional capabilities as well as with the duration of disease. Prefrontal perfusion correlated with cognitive measures, and motor cortical perfusion correlated with physical disability and activities of daily living scores. We found no significant clinical correlations with sensory cortical perfusion. Single-photon-emission computed tomography may be a sensitive method for assessing disease progression in clinical trials and pharmacologic intervention.

P3 event related evoked potentials in pregnancy

Cognitive function using P3 auditory event related evoked response was examined in 18 pregnant women of age group 18-25 years (Mean 21.78 +/- 2.1). P3 was obtained from scalp electrodes at CZ, PZ referenced to ear lobules during a task in which the subjects concentrated and pressed the button on hearing high pitched rare clicks in a train of low-pitched frequent and high pitched rare clicks. Latency and amplitude of P3 was compared with age matched twelve non-pregnant women. There was a significant increase in P3 latency and amplitude in the pregnant group suggesting that changed milieu of pregnancy does affect generators of P3 component of event related potential and cognitive functions of the brain.

Virologic surveillance of poliomyelitis in Delhi

OBJECTIVE

Virologic surveillance of poliomyelitis to monitor the transmission of wild polio virus in the community.

STUDY AREA

All major hospitals of Delhi and surrounding area.

METHODS

Stool samples were collected from 1221 cases of acute flaccid paralysis during 1992-1994 and were subjected to virus isolation on RD and HEp2 cell line. Viruses isolated were analyzed further by microneutralization test using polio and nonpolio antisera. The polio isolates were further characterized as vaccine or wild type using ELISA and probe technology.

RESULTS

Out of the 1221 cases tested, virus was isolated in 57.4%. Among the virus positive cases, polio was isolated in 57% and in 43% non polio entero viruses were detected. The most prevalent was polio virus type 1. Most of the strains were wild type.

CONCLUSION

Wild polio virus was prevailing in the community under study between the years 1992-1994.

BCR/ABL-negative primitive progenitors suitable for transplantation can be selected from the marrow of most early-chronic phase but not accelerated-phase chronic myelogenous leukemia patients

We have previously reported that selection of marrow cells on the basis of the CD34+HLA-DR- phenotype (34+DR-) may result in the recovery of Philadelphia chromosome (Ph)- and BCR/ABL-negative long-term culture-initiating cells (LTC-IC) in selected patients with chronic myelogenous leukemia (CML). We now present data on 27 early chronic-phase ([ECP] studied within 1 year after diagnosis) and 23 advanced-phase ([AP] late chronic phase, ie, studied >1 year from diagnosis, or accelerated phase) CML patients. Fluorescence-activated call-sorting (FACS)-selected 34+DR- and 34+DR+ cells were subjected to reverse transcriptase-polymerase chain reaction and fluorescence in situ hybridization. These cells were also cultured in long-term bone marrow culture for 1 to 5 weeks to examine the number of LTC-IC and the presence or absence of the BCR/ABL gene rearrangement in progeny of primitive LTC-IC. The number of 34+DR- cells and LTC-IC present in ECP CML marrow was similar to that in normal (NL) marrow, whereas the numbers were reduced in AP CML. Furthermore, 34+DR- cells from more than 80% of ECP CML patients were BCR/ABL mRNA- and Ph-negative and contained only BCR/ABL mRNA- and Ph-negative LTC-IC, whereas 34+DR- cells and LTC-IC from less than 40% of AP CML patients were BCR/ABL mRNA- and Ph-negative. In contrast to NL marrow, 34+DR+ cells from CML marrow, irrespective of clinical stage, contained large numbers of LTC-IC. CML 34+DR+ cells and LTC-IC were BCR/ABL mRNA- and Ph-positive. Since these studies suggested that a population of primitive progenitors that are Ph-negative can be selected from steady-state marrow in some ECP CML patients, we determined if similar results could be obtained when large quantities of marrow sufficient for transplantation are processed. We demonstrate that 1 to 3 x 10(5) BCR/ABL mRNA-negative 34+DR- cells/kg recipient body weight, containing only BCR/ABL mRNA-negative LTC-IC, can be obtained from a 2- to 2.5-L marrow collection by sequential COBE Spectra apheresis (COBE BCT, Lakewood, CO), CD34+ enrichment using the CEPRATE SC Cell-Concentrator (CellPro, Bothell, WA), and high-speed FACS. Thus, large-scale selection of a BCR/ABL mRNA- and Ph-negative 34+DR- cell population is possible in a fraction of chronic-phase CML patients, in whom these cells could be used to reconstitute the hematopoietic compartment following autologous transplantation.

Nucleotide sequence and expression of ribosomal protein S3 mRNA during embryogenesis in the Mexican axolotl (Ambystoma mexicanum)

We have isolated and sequenced a full-length (0.9 kb) cDNA clone of ribosomal protein S3 by subtraction hybridization using a single-stranded cDNA library from stage 25-27 (tracer) and the mRNA from stage 15-17 (driver) of embryonic Mexican axolotl (Ambystoma mexicanum). The axolotl is a unique animal model for studying heart development as well as myofibrillogenesis because it carries a mutation in gene c. The deduced amino acid sequence of axolotl S3 protein shows about 93.9% identity with human S3 protein over a 243 amino acid residue overlap. When compared with mouse and Xenopus laevis ribosomal S3 proteins, the axolotl sequenc shows 94.3 and 93.9% identity respectively. Interestingly, the axolotl S3 sequence shows higher identity at the nucleic acid level with human and/or other mammals than with Xenopus. The S3 transcript, as determined by RT-PCR, is present at stage 2-4 in a lower amount and the onset of transcription is most likely at the beginning of gastrulation (10-12). The expression level of S3 transcripts reaches a maximum by mid gastrulation (stages 13-14) and then follows a biphasic pattern being lower at stages 16-17 with subsequently steady increases until the mid tailbud stages (25-27).

Interferon-alpha restores normal beta 1 integrin-mediated inhibition of hematopoietic progenitor proliferation by the marrow microenvironment in chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) progenitors show decreased adhesion to stroma and fibronectin (FN) through beta 1 integrin receptors. We have previously shown that interferon-alpha (IFN-alpha) restores beta 1 integrin-mediated adhesion of CML progenitors to stroma. Because beta1 integrins transmit proliferation inhibitory signals from the microenvironment to normal hematopoietic progenitors, we hypothesized that decreased integrin-mediated adhesion of CML progenitors contributes to their continuous proliferation when in contact with stroma and that IFN-alpha treatment, by restoring integrin-mediated adhesion, also restores integrin-mediated microenvironmental inhibition of CML progenitor proliferation. We show here that, in contrast to normal colony-forming cells (CFC), the percentage of malignant CML CFC in S-phase was not significantly reduced following coculture with stromal layers. However, IFN-alpha treatment resulted in a significant reduction in the proliferation of CML CFC on coculture with stroma. This effect was not because of a direct antiproliferative effect of IFN-alpha on CML CFC because the proliferation of IFN-alpha treated CML CFC kept in suspension culture was not reduced. We examined the role of restored signaling through beta 1 integrin receptors in IFN-alpha induced inhibition of CML progenitors in two sets of experiment. In the first set of experiments, we demonstrated that proliferation of IFN-alpha-treated CML CFC, but not untreated CML CFC, was significantly reduced following coculture with 33/66-kD and 75-kD FN fragments, recognized by alpha 4 beta 1 and alpha 5 beta 1 integrins respectively. In a second set of experiments, we demonstrate that direct stimulation of integrin receptors by crosslinking with blocking antibodies to alpha 4, alpha 5, and beta 1 integrins and secondary goat antimouse antibodies resulted in significant reduction in proliferation of normal and IFN-alpha treated CML progenitors but not untreated CML CFC. These studies indicate that CML hematopoietic progenitors are unresponsive to beta 1-integrin mediated proliferation inhibition and that IFN-alpha not only restores beta 1 integrin-mediated adhesion but also beta1-mediated microenvironmental inhibition of CML progenitor proliferation. These observations may explain, at least in part, the therapeutic efficacy of IFN-alpha in CML.

Five conversations: reflections of stakeholders on the impact of the ethnocultural communities facing AIDS study

This paper reports on issues identified in conversations held between one of the Ethnocultural Communities Facing AIDS Study (ECFA) investigators and five stakeholders associated with this experiment in collaborative and participatory research. The stakeholders reflect on their experiences in partnering with university-based researchers, resistance in ethnocultural communities to being researched, and the next steps implicated by the research in question. The problem of HIV/AIDS in ethnocultural communities in Canada is, relative to the mainstream, also viewed as a symbol of disadvantage in these communities. The stakeholders suggest that to address these deeper concerns, there must be vital, dynamic, and enduring communication between researchers, community representatives, and government at all levels, in the process of identifying solutions and implementing them in the present.

The sequencing expression, purification, and steady-state kinetic analysis of quinolinate phosphoribosyl transferase from Escherichia coli

The nadC gene from Escherichia coli was isolated and sequenced. The gene was then cloned into an expression vector and, following transformation, the resulting bacteria were able to produce quinolinate phosphoribosyl transferase as about 2% of the soluble protein. The enzyme was purified in five steps leading to a homogeneous preparation. The enzyme reaction shows an ordered binding mechanism where the magnesium ion complex of 5-phosphoribosyl-1-pyrophosphate binds first followed by quinolinic acid. The products are pyrophosphate CO2, and nicotinate mononucleotide. Product inhibition studies show that nicotinate mononucleotide is a competitive inhibitor with respect to 5-phosphoribosyl-1-pyrophosphate while pyrophosphate is noncompetitive with respect to both 5-phosphoribosyl-1-pyrophosphate and quinolinic acid. Phthalic acid and fructose-1,6-bisphosphate were used as dead-end inhibitors. Phthalate was competitive with respect to quinolinic acid but uncompetitive with respect to 5-phosphoribosyl-1-pyrophosphate. Fructose-1,6-bisphosphate was a competitive inhibitor with respect to 5-phosphoribosyl-1-pyrophosphate and noncompetitive with respect to quinolinic acid. The Km values for the substrates are 15.6 microM for 5-phosphoribosyl-1-pyrophosphate and 6.4 microM for quinolinic acid.

Serodiagnosis of tuberculosis

To overcome limitations of the conventional laboratory tests for the diagnosis of tuberculosis, attempts have been made in the past to develop a good serodiagnostic test. Until the availability of ELISA results obtained with various immunological techniques were of limited use. Even with ELISA, early attempts to estimate specific antimycobacterial antibodies in the serum were based on the use of crude mycobacterial antigens resulting in a very high false positivity. Better results were obtained with purified antigens. Various purified and semipurified antigens which when used in the ELISA test for estimating antibodies in the serum and other body fluids in cases of tuberculosis have given encouraging results. These include a glycolipid antigen from Myc. bovis BCG (ST = 88%, SP = 96%), antigen '5' (ST = 72%, SP = 91%) and a 38 Kd protein antigen (ST = 83%). Estimation of various mycobacterial antigens in different clinical specimens has also been studied using ELISA technique. Encouraging results have been obtained with the detection of a 43 Kd antigen, Lipoarabinomannan antigen and antigen '5' in the serum, CSF and other body fluids of cases of tuberculosis (ST = 80-100%, SP = 93-100%). The serological tests by detecting specific mycobacterial antigens and antibodies can be of great help in diagnosing the smear negative tuberculosis as these are rapid, inexpensive and simple to perform.

Autografting for chronic myelogenous leukemia

Two thirds of patients with chronic myelogenous leukemia do not have suitable donors for allogeneic transplantation. As for other leukemias, autografting may potentially be curative, because normal Ph- hematopoietic stem cells persist in the marrow and blood of patients with chronic myelogenous leukemia. Several studies indicate that use of unpurged autologous blood or marrow grafts may extend survival for patients undergoing transplantation in chronic phase. Ex vivo or in vivo purging of chronic myelogenous leukemia marrow or blood prior to autografting may result in increased cytogenetic remissions after transplantation in those patients in whom the Ph+ clone can be eliminated. However, when the Ph+ clone cannot be eliminated, use of purged rather than unpurged autografts provides no advantage and may be associated with increased graft failure. Although sustained cytogenetic remissions have not been observed, autografting may result in a plateau in the survival curve not observed with conventional chemotherapy. Efforts are currently directed toward developing improved methods of purging as well as posttransplantation treatments directed against leukemic cells persisting after myeloablative therapy.

Effect of a short course of indomethacin on gastric mucosal blood flow using endoscopic laser-Doppler velocimetry

OBJECTIVE

To assess the effect of a short course of indomethacin on gastric mucosal blood flow (GMBF).

METHODS

Patients with musculo-skeletal pain of recent origin and were prescribed a short course of therapy with indomethacin (25 mg tid for 7 days) were studied Baseline measurements of GMBF were carried out using endoscopic laser-Doppler velocimetry prior to starting indomethacin. At sites on the antrum, incisura, lesser and greater curvatures, and fundus. GMBF measurements were repeated after indomethacin therapy, as above and also on sites of erosions, it any.

RESULTS

Baseline GMBF at sites on the antrum, incisura, greater and lesser curvatures, and fundus were (mean) 8.6, 7.9, 8.8, 8.5 and 8.7 volts, respectively. Post-therapy values did not differ from the corresponding baseline values (8.7, 8.5, 8.6, 8.6 and 8.3 volts, respectively). However, ten of the 16 patients developed gastric mucosal erosions and the mean GMBF on these sites of erosion was significantly reduced (6.6 +/- 1.3 volts, p < 0.05).

CONCLUSIONS

A short course of indomethacin therapy produces a patchy decrease in blood flow in the gastric mucosa and erosions were seen in these areas.

Treatment of marrow stroma with interferon-alpha restores normal beta 1 integrin-dependent adhesion of chronic myelogenous leukemia hematopoietic progenitors. Role of MIP-1 alpha

The mechanisms by which interferon-alpha (IFN-alpha) restores normal hematopoiesis in chronic myelogenous leukemia (CML) are not well understood. We have recently demonstrated that IFN-alpha acts directly on CML hematopoietic progenitors to restore their adhesion to marrow stroma by modulating beta 1 integrin receptor function. In the present study we examined the effect of IFN-alpha treatment of marrow stroma on subsequent adhesion of CML progenitors. Stromal layers were preincubated with IFN-alpha (10,000 microns/ml) for 48 h. Subsequent coincubation with CML progenitors for 2 h resulted in significantly increased adhesion of CML progenitors. We demonstrated that alpha 4 beta 1 and alpha 5 beta 1 integrin receptors were involved in the enhanced adhesion of CML progenitors, suggesting that IFN-alpha-treated stroma can upregulate CML integrin function. This effect is due, at least in part, to IFN-alpha-induced increased stromal production of the chemokine macrophage inflammatory protein-1 alpha (MIP-1 alpha), which upregulates beta 1 integrin-dependent adhesion of CML progenitors to stroma. Thus, IFN-alpha treatment of marrow stroma restores beta 1 integrin-dependent adhesion of CML progenitors, at least in part through induction of MIP-1 alpha production. These observations provide further insights into mechanisms by which IFN-alpha may restore normal hematopoiesis in CML.

Comparison of gastric mucosal blood flow in normal subjects and in patients with portal hypertension using endoscopic laser-Doppler velocimetry

OBJECTIVE

To compare gastric mucosal blood flow (GMBF) in normal subjects with that in patients with portal hypertension with or without portal hypertensive gastropathy (PHG).

METHODS

GMBF was measured by endoscopic laser-Doppler velocimetry in 20 gastroscopically normal subjects and 30 patients with portal hypertension with or without PHG. The effects of breath-holding (vasomotor reflex), submucosal epinephrine and sublingual isosorbide dinitrate were also studied.

RESULTS

In normal subjects, GMBF on the greater curvature was (mean +/- SD) 9.5 +/- 1.3 V and on the lesser curvature, 9.1 +/- 1.9 V. Breath-holding caused a reduction in GMBF by 57.1 +/- 13.7%, submucosal epinephrine reduced it by 41.5 +/- 21.5% and sublingual isosorbide caused a rise of 25.8 +/- 15.2%. The GMBF on the greater and lesser curvature respectively in patients with mild PHG (7.7 +/- 1.2 V and 7.7 +/- 0.8 V) and those with severe PHG (6.5 +/- 3.5 V and 6.3 +/- 2.2 V), was significantly less than that in normal subjects (p < 0.05 and p < 0.001 respectively). Vasomotor reflex was blunted in patients with mild and severe PHG (23.3% +/- 20.3 and 23.1% +/- 17.7 respectively, p < 0.001). Responses to submucosal epinephrine and sublingual isosorbide were similar to those recorded in normal subjects.

CONCLUSIONS

Patients with portal hypertension have significantly reduced GMBF and significantly attenuated vasomotor reflex in the gastric vascular bed as compared to normal subjects.

Abnormal function of the bone marrow microenvironment in chronic myelogenous leukemia: role of malignant stromal macrophages

The bone marrow microenvironment supports and regulates the proliferation and differentiation of hematopoietic cells. Dysregulated hematopoiesis in chronic myelogenous leukemia (CML) is caused, at least in part, by abnormalities in CML hematopoietic progenitors leading to altered interactions with the marrow microenvironment. The role of the microenvironment itself in CML has not been well characterized. We examined the capacity of CML stroma to support the growth of long-term culture-initiating cells (LTC-IC) obtained from normal and CML marrow. The growth of normal LTC-IC on CML stroma was significantly reduced compared with normal stroma. This did not appear to be related to abnormal production of soluble factors by CML stroma because normal LTC-IC grew equally well in Transwells above CML stroma as in Transwells above normal stroma. In addition, CML and normal stromal supernatants contained similar quantities of both growth-stimulatory (granulocyte colony-stimulating factor (CSF), interleukin-6, stem cell factor, granulocyte-macrophage CSF, and interleukin-1 beta) and growth-inhibitory cytokines (transforming growth factor-beta, macrophage inflammatory protein-1 alpha, and tumor necrosis factor-alpha). The relative proportion of different cell types in CML and normal stroma was similar. However, polymerase chain reaction and fluorescence in situ hybridization studies showed the presence of bcr-abl-positivo cells in CML stroma, which were CD14+ stromal macrophages. To assess the effect of these malignant macrophages on stromal function, CML and normal stromal cells were separated by fluorescence-activated cell sorting into stromal mesenchymal cell (CD14-) and macrophage (CD14+) populations. CML and normal CD14- cells supported the growth of normal LTC-IC equally well. However, the addition of CML macrophages to normal or CML CD14- mesenchymal cells resulted in impaired progenitor support. This finding indicates that the abnormal function of CML bone marrow stroma is related to the presence of malignant macrophages. In contrast to normal LTC-IC, the growth of CML LTC-IC on allogeneic CML stromal layers was not impaired and was significantly better than that of normal LTC-IC cocultured with the same CML stromal layers. These studies demonstrate that, in addition to abnormalities in CML progenitors themselves, abnormalities in the CML marrow microenvironment related to the presence of malignant stromal macrophages may contribute to the selective expansion of leukemic progenitors and suppression of normal hematopoiesis in CML.

T lymphocytes cultured from chronic myelogenous leukemia bone marrow suppress autologous hematopoietic progenitors

In vitro culture of T lymphocytes infiltrating solid tumors has resulted in populations with significant, and sometimes selective, anti-tumor activity. In this study we evaluated the ability of T lymphocyte populations generated from the marrow of patients with chronic myelogenous leukemia (CML) to suppress autologous hematopoietic progenitors. T lymphocyte populations were obtained by culture of CML bone marrow mononuclear cells (BMMNC) with low dose rIL-2 (25 U/ml) after initial PHA stimulation, and restimulation during culture with autologous marrow cells. Preincubation of the cultured CML T lymphocytes in close contact with autologous BMMNC resulted in significant, dose-related suppression of autologous CFU-MIX and BFU-E colonies (P < 0.001). Close contact between effectors and targets was important for progenitor suppression. Progenitor suppression was mediated by CD4-positive T lymphocytes. In contrast to the significant suppression of autologous progenitors by CML T lymphocytes, T lymphocytes from normal bone marrow did not suppress autologous progenitors. We conclude that T lymphocyte populations with significant autologous progenitor suppressing ability can be generated from CML marrow. These observations may be of therapeutic value in CML.

Prevalence of toxoplasmosis in Indian women of child bearing age

A total of 2075 women in child bearing age and with past bad obstetrical history were serologically examined by the indirect immunofluorescence antibody test for Toxoplasma antibodies. 160 (7.72%) serum samples were positive with a titre of 1:64 or more. Maximum prevalence as well as highest titres of antibodies were seen in women aged 36 years and above indicating repeated infections. No association between seropositivity and contact with animals was observed. The low overall prevalence is due to infrequent and uncommon practices of ingesting undercooked or uncooked food especially meat.