Cardiovascular reflex abnormalities in children and adolescents with diabetes mellitus

OBJECTIVE

To assess the usefulness of specific cardiovascular reflex tests in childhood and to estimate the prevalence of cardiovascular reflex abnormalities among children with IDDM. In adults, abnormal cardiovascular reflexes are a frequent complication of diabetes, associated with increased morbidity and mortality.

RESEARCH DESIGN AND METHODS

We measured heart-rate responses to deep breathing and standing in ambulatory children with and without IDDM between 6-19 yr of age. A subgroup of the IDDM patients was retested after 1 yr.

RESULTS

We found the best techniques for detecting cardiovascular reflex abnormality in children were as follows: to record heart-rate responses to deep breathing either as the change in heart rate corrected for inspiratory heart rate or as the ratio of R-R intervals during expiration and inspiration; and to use the Maximum-minimum ratio for heart-rate responses to standing. HR-DBc was lower in diabetic than nondiabetic children (28.6 +/- 9.2% [n = 248] vs. 33.6 +/- 6.8% [n = 60]; P < 0.0005). Similarly, E:I was lower in children with IDDM than control subjects (1.42 +/- 0.19 [n = 248] vs. 1.52 +/- 0.15 [n = 60]; P < 0.0005). In the IDDM group, 21% of the children had abnormal HR-DBc or E:I responses. HR-STND M/m was lower in children with IDDM than control subjects (1.28 +/- 0.20 [n = 167] vs. 1.38 +/- 0.22 [n = 45]; P < 0.014). Among children with IDDM, 11.4% had abnormal HR-STND M/m responses. Overall, 29% of IDDM children tested abnormal in either HR-DBc or HR-STND M/m; 3% were abnormal in both tests. We found no correlation of HbA1c levels (n = 74) or duration of diabetes with either HR-DB, expiration to inspiration (n = 248), or HR-STND M/m (n = 167). In patients who were reevaluated after 1 yr we found a high correlation of the first and repeat HR-DBc tests (r = 0.47, n = 75, P < 0.0001), E:I (r = 0.53, n = 75, P < 0.0001), and HR-STND M/m (r = .49, n = 37, P < 0.002), but no evidence of an increased number of children with cardiovascular reflex abnormality.

CONCLUSIONS

With easily performed HR-DB and HR-STND tests, we detected cardiovascular reflex abnormality in 29% of children with IDDM. We found no correlation of changes in HR-DB and HR-STND with HbA1c or duration of diabetes. These tests provide an objective clinical measurement to monitor autonomic neuropathy in children with diabetes.

Successful outcome of progressive multifocal leukoencephalopathy with cytarabine and interferon

The prognosis of patients with progressive multifocal leukoencephalopathy is poor, with few patients showing remission or surviving. We describe a 37-year-old man who developed progressive multifocal leukoencephalopathy in association with sarcoidosis. Despite treatment with cytarabine and acyclovir, he continued to deteriorate. Shortly following the addition of interferon alfa, he made a dramatic improvement, regaining full functional independence. The use of interferon alfa in addition to cytarabine in such patients offers a new therapeutic approach worthy of further trial.

Relative efficacy of tazobactam, sulbactam and clavulanic acid in enhancing the potency of ampicillin against clinical isolates of Enterobacteriaceae

Three beta-lactamase inhibitors were combined with ampicillin in a fixed 2:1 ratio. The activity of ampicillin was enhanced by tazobactam and by clavulanic acid, and to a lesser extent by sulbactam when tested against fresh clinical isolates of Enterobacteriaceae. At a concentration of 8 micrograms/ml, ampicillin alone inhibited 49.6% of 2,434 consecutive isolates of enteric bacilli compared to 81% inhibited by ampicillin combined with tazobactam or clavulanic acid and 69.3% inhibited by the sulbactam/ampicillin combination. A four-fold or greater reduction in ampicillin MICs was observed in comparable numbers of isolates with all three combinations, but the most marked effects were seen with strains that were highly resistant to ampicillin.

Serology and anthrax in humans, livestock and Etosha National Park wildlife

Results are presented from a number of epidemiological studies using enzyme immunoassays (EIA) based on the purified anthrax toxin antigens, protective antigen, lethal factor and oedema factor. Studies on sera from a group of 62 human anthrax patients in Turkey and from cattle in Britain following two unrelated outbreaks of anthrax show that EIA using protective antigen can be a useful diagnostic aid and will detect subclinical infections in appropriate circumstances. A serological survey on wildlife in the Etosha National Park, Namibia, where anthrax is endemic, showed that naturally acquired anthrax-specific antibodies are rare in herbivores but common in carnivores; in carnivores, titres appear to reflect the prevalence of anthrax in their ranges. Problems, as yet unresolved, were encountered in studies on sera from pigs following an outbreak of anthrax on a farm in Wales. Clinical details, including treatment, of the human and one of the bovine outbreaks are summarized and discussed in relation to the serological findings.

Prevention of transfusion-associated cytomegalovirus infection in neonatal patients by the removal of white cells from blood

The usual methods employed to reduce the risk of transfusion-associated cytomegalovirus (TA CMV) disease have been to transfuse blood or cellular blood components that are CMV antibody-negative or to administer deglycerolized frozen red cells. To determine if the reduction of white cells (WBCs) in blood by filtration will also eliminate TA CMV disease in a high-risk population, 48 surviving very low birth weight (less than 1250 g) neonatal infants born to CMV-seronegative mothers at three participating institutions in the Hartford, Connecticut area and receiving at least one CMV-seropositive blood transfusion were studied. The incidence of TA CMV disease in 26 neonatal patients who received blood prepared by a modified spin-cool-filter technique and in 22 neonatal patients who received blood filtered through a WBC-reduction filter was compared with the incidence of transfusion-associated disease in similar populations reported in other studies. The CMV antibody prevalence of the blood donor population was found to be 37 percent. At the time of discharge of the individual neonatal infants in the population studied, and/or 2 to 6 months later, 47 of the 48 who had undergone transfusion had CMV antibody-negative serologic tests and/or urine culture. The other infant transiently seroconverted because of passive transfer of the antibody. None of the 48 neonatal infants had clinical evidence of CMV infection. This study indicates that WBC reduction of donor blood can reduce and perhaps prevent TA CMV disease in high-risk neonatal patients.

PCR-detected genital papillomavirus infection: prevalence and association with risk factors for cervical cancer

In an investigation conducted in student health clinic patients, the polymerase chain reaction was used to detect human papillomavirus (HPV) DNA, thereby allowing measurement of the prevalence of HPV infection and study of the association between HPV infection and risk factors for cervical cancer. Of 159 women eligible to participate, 105 (66%) provided a specimen of cervical cells for HPV typing, and also answered an interviewer-administered questionnaire which sought information on risk factors for cervical cancer. Nucleic acid extracted from cervical cells was screened with primers for HPV types 6, 11, 16, 18, 33 and with an HPV Consensus primer. Overall, the prevalence of HPV infection was 18.1%, while for HPV-6/11 it was 2.9% and for HPV-16/18 it was 10.5%. There were statistically significant increases in risk of HPV infection with a history of ever having smoked cigarettes (overall, and for HPV-16 alone) and with a history of usually having sexual intercourse during menstrual periods (overall, but not for HPV-16), and these associations were independent of the effects of age at first sexual intercourse and number of sexual partners. The latter 2 variables, as well as the total number of occasions of sexual intercourse, a history of anal intercourse, and a history of ever having used oral contraceptives, were not associated with statistically significant alterations in risk of HPV infection.

Kidney biopsy in systemic lupus erythematosus. II. Survival analyses according to biopsy results

Renal biopsy specimens from 123 patients with systemic lupus erythematosus (SLE) seen between 1970 and 1984 were assessed according to the World Health Organization classification and according to the presence of proliferative, active, or chronic renal lesions. Survival analysis was used to study the determinants of mortality. Survival rates were higher for patients with minimal lesions, intermediate for patients with focal or diffuse proliferative nephritis, and low for patients with glomerular sclerosis. The presence of proliferative and chronic lesions was associated with a higher risk of dying. Renal biopsy results are helpful in predicting prognosis for all-cause mortality in patients with SLE.

Differences in oncogenic potency but not target cell specificity distinguish the two forms of the BCR/ABL oncogene

Two forms of activated BCR/ABL proteins, P210 and P185, that differ in BCR-derived sequences, are associated with Philadelphia chromosome-positive leukemias. One of these diseases is chronic myelogenous leukemia, an indolent disease arising in hematopoietic stem cells that is almost always associated with the P210 form of BCR/ABL. Acute lymphocytic leukemia, a more aggressive malignancy, can be associated with both forms of BCR/ABL. While it is virtually certain that BCR/ABL plays a central role in both of these diseases, the features that determine the association of a particular form with a given disease have not been elucidated. We have used the bone marrow reconstitution leukemogenesis model to test the hypothesis that BCR sequences influence the ability of activated ABL to transform different types of hematopoietic cells. Our studies reveal that both P185 and P210 induce a similar spectrum of hematological diseases, including granulocytic, myelomonocytic, and lymphocytic leukemias. Despite the similarity of the disease patterns, animals given P185-infected marrow developed a more aggressive disease after a shorter latent period than those given P210-infected marrow. These data demonstrate that the structure of the BCR/ABL oncoprotein does not affect the type of disease induced by each form of the oncogene but does control the potency of the oncogenic signal.

Cancer risk in patients with diabetes mellitus

Cancer incidence was ascertained in a population-based cohort of 51,008 patients in Uppsala, Sweden, who were given a discharge diagnosis of diabetes mellitus during 1965-83. Complete follow-up through 1984 with exclusion of the first year of observation showed that the observed number of cancers in females (1,294) was eight percent higher than expected (relative risk [RR] = 1.1, 95 percent confidence interval = 1.0-1.1), whereas in males the observed number (1,123) was close to the expected (RR = 1.0, 0.9-1.1). Significantly increased risks of pancreatic (RR = 1.4, 1.2-1.7), primary liver (RR = 1.5, 1.2-1.7), and endometrial (RR = 1.5, 1.2-1.8) cancers and a lower than expected number of prostatic cancers (RR = 0.7, 0.7-0.9) were found in this cohort of diabetic patients. The excess risk of pancreatic cancer was similar in females and males and evident both during one through four years (RR = 1.7, 1.4-2.1) and five through nine years (RR = 1.3, 0.9-1.7) of follow-up, but not thereafter. A similar pattern was found for primary liver cancer, but the RRs were generally higher in males than in females.

The 5' non-coding region of the BCR/ABL oncogene augments its ability to stimulate the growth of immature lymphoid cells

The Philadelphia chromosome (Ph1, t9:22;34:q11) is a reciprocal translocation between chromosome 22 and chromosome 9 which results in the formation of the chimeric BCR/ABL oncogene. Alternative forms of BCR/ABL are produced by splicing different sets of exons of the BCR gene to a common set of c-ABL sequences. This results in the formation of an 8.7 kilobase mRNA that encodes the P210 BCR/ABL gene product or a 7.0 kilobase mRNA that encodes the P185 BCR/ABL gene product. Both BCR/ABL transcripts derive their 5' non-coding sequences from the BCR gene locus. This 5' region is over 500 nucleotides in length, has a GC content greater than 75% and has a short open reading frame. To determine if this unusual 5' non-coding region plays a role in BCR/ABL transformation, we prepared retroviral vectors containing identical BCR/ABL coding regions but differing in the length of the BCR 5' non-coding region. Matched viral stocks were evaluated for their ability to transform bone marrow in vitro and for their ability to cause tumors when inoculated into 3- to 4-week-old mice. In this report we present the unexpected finding that the BCR/ABL 5' non-coding region augments the transforming activity of both P210 and P185 BCR/ABL in vitro. In vivo, BCR/ABL is a weak tumorigenic agent and its potency is enhanced by the presence of the 5' non-coding region.

Maternal listeriosis in pregnancy without fetal or neonatal infection

Maternal infection with Listeria monocytogenes without fetal or neonatal involvement is relatively rare. Eleven cases arising in England and Wales between 1967 and 1988 are presented.

Induction of a chronic myelogenous leukemia-like syndrome in mice with v-abl and BCR/ABL

The v-abl gene in Abelson virus induces pre-B-cell lymphoma in mice while the BCR/ABL oncogene is associated with chronic myelogenous leukemia and some cases of acute lymphocytic leukemia in humans. Understanding the mechanisms by which these oncogenes affect various cell types has been hampered by a paucity of experimental systems that reproduce the range of biological effects associated with them. We have developed an experimental system in which murine hematopoietic stem cell populations are infected with either v-abl or BCR/ABL retroviruses and are used to reconstitute lethally irradiated mice. Irrespective of the form of activated abl, greater than 90% of the animals reconstituted with such cells develop tumors. About 50% of them develop a myeloproliferative syndrome that shares several features with the chronic phase of chronic myelogenous leukemia; the remaining animals succumb to pre-B-cell lymphomas. The myeloproliferative syndrome is characterized by large numbers of clonally derived, infected myeloid cells. This model will allow study of the mechanism by which activated abl genes affect hematopoietic precursors in chronic myelogenous leukemia. Furthermore, our results demonstrate that introduction of an activated abl gene into the appropriate target cell, not the structure of the gene, is the major determinant in myeloid cell specificity.

Linking diploma and bachelor's degree nursing education: an Illinois experiment

Changes in the traditional applicant pool, coupled with increased numbers of diploma and associate degree graduates seeking additional nursing education, have promoted the development of nontraditional educational pathways in collegiate schools of nursing. The authors describe a unique cooperative arrangement with a provision that allows students to transfer to a bachelor's nursing program before completing their diploma studies. On the basis of initial student and faculty reports, standardized test performance, academic performance, and National Council Licensure Examination scores, this educational experiment has been successful. The planning, implementation, and evaluation of the project required considerable time and effort on the part of the administration and faculty of both schools. The program's success has led the schools to consider other cooperative ventures. The authors conclude that this approach may serve as a model for other schools interested in providing educational mobility for diploma students.

Base changes at position 792 of Escherichia coli 16S rRNA affect assembly of 70S ribosomes

To investigate the function of base 792 of 16S rRNA in 30S ribosomes of Escherichia coli, the wild-type (adenine) residue was changed to guanine, cytosine, or uracil by oligonucleotide-directed mutagenesis. Each base change conferred a unique phenotype on the cells. Cells containing plasmid pKK3535 with G792 or T792 showed no difference in generation time in LB broth containing ampicillin, whereas cells with C792 exhibited a 20% increase in generation time in this medium. To study the effect on cell growth of a homogeneous population of mutant ribosomes, the mutations were cloned into the 16S rRNA gene on pKK3535 carrying a spectinomycin-resistance marker (thymine at position 1192), and the cells were grown with spectinomycin. Cells containing G792 or C792 showed 16% and 56% increases in generation time, respectively, and a concomitant decrease in 35S assimilation into proteins. Cells with T792 did not grow in spectinomycin-containing medium. Maxicell analyses indicated decreasing ability to form 70S ribosomes from 30S subunits containing guanine, cytosine, or uracil at position 792 in 16S rRNA. It appeared that C792-containing 30S ribosomes had lost the ability to bind initiation factor 3.

Evaluation of a diffusion strategy for school-based hypertension education

The purpose of this research was to evaluate the effectiveness of hypertension (HBP) education within a population of sixth grade students (n = 1204) and their parents (n = 1446). The "3Rs and HBP" curriculum attempts to diffuse the HBP information from teachers, to pupils and then to parents using the sixth grade son/daughter as a "health messenger." This curriculum was tested with and without a home blood pressure measurement component versus controls in 21 schools randomly assigned to the three conditions. Postintervention data were collected from students at school and from their parents at home interviews. Students were compared for knowledge, blood pressure measurement skill, and home diffusion activities. Parents were compared for knowledge, risk factor reduction, blood pressure, care-seeking, and compliance behaviors. Student self-esteem and family interactions were investigated as possible intervening variables in the diffusion process. Student knowledge, BP measurement skills, and diffusion to parents was increased by the 3Rs and HBP curriculum with the home component. Parental effects beyond the diffusion process were limited to knowledge improvement in certain groups. Family interaction (level and style) was found to be a significant intervening variable in the diffusion process.

Alternative forms of the BCR-ABL oncogene have quantitatively different potencies for stimulation of immature lymphoid cells

The Philadelphia chromosome (t9:22;q34:q11) is found in more than 90% of patients with chronic myelogenous leukemia, in 10 to 20% of patients with acute lymphocytic leukemia, and in 1 to 2% of patients with acute myelogenous leukemia. Alternative chimeric oncogenes are formed by splicing different sets of BCR gene exons on chromosome 22 across the translocation breakpoint to a common set of ABL oncogene sequences on chromosome 9. This results in an 8.7-kilobase mRNA that encodes the P210 BCR-ABL gene product commonly found in patients with chronic myelogenous leukemia or a 7.0-kilobase mRNA that produces the P185 BCR-ABL gene product found in most Philadelphia chromosome-positive patients with acute lymphocytic leukemia. To compare the efficiency of growth stimulation by these two proteins, we derived cDNA clones for each with identical 5' and 3' untranslated regions and expressed them from retrovirus vectors. Matched stocks were compared for potency to transform immature B-lymphoid lineage precursors. The growth-stimulating effects of P185 for this cell type were found to be significantly greater than those of P210. Structural changes in BCR may regulate the effectiveness of the ABL tyrosine kinase function, as monitored by lymphocyte growth response. Changes in mitogenic potency may help to explain the more acute leukemic presentation usually associated with expression of the P185 BCR-ABL oncogene.

Mapping of the creatine kinase M gene to 19q11----q12 in the rabbit genome

The chromosomal localization of the gene for creatine kinase M has been determined to be on rabbit chromosome 19 at q11----q12 by in situ molecular hybridization. The results show significant cross-hybridization of the creatine kinase, muscle (CKMM) probe to the previously mapped creatine kinase, brain (CKBB) locus at 20q13----qter, and therefore provide independent support for the localization of CKBB at that site.

The effects of chronic otitis media on motor performance in 5- and 6-year-old children

Two 16-member groups of 5- and 6-year-old children, one group with a history of chronic otitis media and one without such a history, were tested on three measures of motor performance. These were the Motor Accuracy Test-Revised, the Stott Test of Motor Impairment, and measures of duration of standing balance. These instruments assess, respectively, fine motor coordination, overall motor skills, and balance. On each of these measures, children with a history of chronic otitis media scored lower than children without such a history. However, when these scores were compared statistically, no significant differences were found between the two groups. Because the results of this study were inconclusive, routine motor performance evaluation of children with a history of chronic otitis media is not advocated at this time.

AIDS education: process, content, and strategies

Education represents the single best option for stopping the tide of the devastating epidemic of AIDS. Although its importance is widely recognized, little has been published to assist practitioners in the development and implementation of effective educational programs. This article presents a planning process, program content, and teaching strategies which can be used for AIDS education in schools, work-sites, and communities.

Concordance of endogenous cortisol and phospholipase A2 levels in gram-negative septic shock: a prospective study

Lipocortins, a group of corticosteroid-induced phospholipase-inhibitory proteins, are thought to play a prominent role in the mediation of the anti-inflammatory effects of steroids. The synthesis and release of these proteins may represent a major endogenous mechanism of regulation of extracellular phospholipase A2 (PLA2) activity. Because soluble PLA2 activity has been associated with circulatory collapse in hyperphospholipasemic conditions, such as septic shock and pancreatitis, we examined the relationship between circulating PLA2 activity and adrenocortical function. In a prospective study of 10 episodes of septic shock, serum PLA2 and cortisol levels correlated significantly in all survivors (p less than 0.0001), whereas such a correlation was absent in all nonsurvivors (p less than 0.07). No significant correlation of cortisol and adrenocorticotropic hormone (ACTH), or PLA2 and ACTH, was found in any patient, suggesting that the stimulus for cortisol release arises from outside the hypothalamic-pituitary axis. These data suggest that, in human beings, the regulation of soluble PLA2 activity may be mediated by adrenocortical hormones, perhaps through the intermediary action of lipocortins.

Expression of a distinctive BCR-ABL oncogene in Ph1-positive acute lymphocytic leukemia (ALL)

The Philadelphia chromosome (Ph1) is a translocation between chromosomes 9 and 22 that is found in chronic myelogenous leukemia (CML) and a subset of acute lymphocytic leukemia patients (ALL). In CML, this results in the expression of a chimeric 8.5-kilobase BCR-ABL transcript that encodes the P210BCR-ABL tyrosine kinase. The Ph1 chromosome in ALL expresses a distinct ABL-derived 7-kilobase messenger RNA that encodes the P185ALL-ABL protein. Since the expression of different oncogene products may play a role in the distinctive presentation of Ph1-positive ALL versus CML, it is necessary to understand the molecular basis for the expression of P185ALL-ABL. Both P210BCR-ABL and P185ALL-ABL are recognized by an antiserum directed to BCR determinants in the amino-terminal region of both proteins. Antisera to BCR determinants proximal to the BCR-ABL junction in CML immunoprecipitated P210BCR-ABL but not P185ALL-ABL. Nucleotide sequence analysis of complementary DNA clones made from RNA from the Ph1-positive ALL SUP-B15 cell line, and S1 nuclease protection analysis confirmed the presence of BCR-ABL chimeric transcripts in Ph1-positive ALL cells. In Ph1-positive ALL, ABL sequences were joined to BCR sequences approximately 1.5 kilobases 5' of the CML junction. P185ALL-ABL represents the product of a BCR-ABL fusion gene in Ph1-positive ALL that is distinct from the BCR-ABL fusion gene of CML.

A flagellar pocket membrane fraction from Trypanosoma brucei rhodesiense: immunogold localization and nonvariant immunoprotection

In contrast to the abundance of detailed information on variant-specific surface coat antigens of African trypanosomes, data on possible common or nonvariant antigens within these protozoa are surprisingly limited. In this study, the cellular localization and protective potential of a previously characterized flagellar pocket membrane (FPM) fraction were determined. Immunogold staining of live trypanosome suspensions at 0 to 4 degrees C by using anti-FPM hyperimmune serum raised in rabbits as the primary antibody revealed specific staining of the parasite surface at the emergence of the flagellum from the flagellar pocket. The same specificity of immunogold localization was obtained for each of three distinct variable antigenic types (VATs) of a serodeme of Trypanosoma brucei rhodesiense Wellcome strain. Products of translated mRNA preparations from each of the VATs were precipitated by the FPM antiserum and revealed identical banding patterns when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by autoradiography. Immunization of mice with FPM fraction protected them against infection by two of the VATs; the third VAT was afforded poor protection. This is the first demonstration of the combined cellular localization, nonvariant nature, and protective potential of a membrane fraction from African trypanosomes.

In vitro transformation of immature hematopoietic cells by the P210 BCR/ABL oncogene product of the Philadelphia chromosome

The Philadelphia chromosome [t(9;22)-(q34;q11)] is the cytogenetic hallmark of human chronic myelogenous leukemia. RNA splicing joins sequences from a gene on chromosome 22 (BCR) across the translocation breakpoint to a portion of the ABL oncogene from chromosome 9, resulting in a chimeric protein (P210) that is an active tyrosine kinase. Although strongly correlated with this specific human neoplasm, and implicated as an oncogene by analogy to the gene product of the Abelson murine leukemia virus, the P210 gene had not been tested directly for oncogenic potential in hematopoietic cells. We have used a retroviral gene-transfer system to express P210 in mouse bone marrow cells. When infected bone marrow is plated under conditions for long-term culture of cells of the B-lymphoid lineage, cells expressing high amounts of P210 tyrosine kinase dominate the culture and rapidly lead to clonal outgrowths of immature lymphoid cells. Expression of P210 is growth-stimulatory but not sufficient for full oncogenic behavior. Some clonal lines progress toward a fully malignant phenotype as judged by increased cloning efficiency in agar suspension and frequency and rapidity of tumor induction in syngeneic mice. Such in vitro systems should be useful in evaluating the sequential and perhaps synergistic involvement of the P210 gene and other oncogenes as models for the progressive changes observed in human chronic myelogenous leukemia.

Prevalence of abnormalities found by sinus x-rays in childhood asthma: lack of relation to severity of asthma

We examined the prevalence of abnormalities found by sinus x-rays in patients with asthma. The overall prevalence of abnormalities found was greater in the patients with asthma, 43 of 138 (31.2%), compared to control patients with dental problems, 0 of 50 (p less than 0.001). However, the percent of patients with abnormalities found by sinus x-rays was the same whether the asthma was mild, requiring minimal medication, or severe, requiring multiple medications. The results provide no support for the hypothesis that sinusitis, as detected by abnormalities found by sinus x-rays, aggravates asthma and promotes increased need for medication to control the asthma.

Trypanosoma rhodesiense: antigenicity and immunogenicity of flagellar pocket membrane components

A low density membrane fraction, isolated from the bloodstream stage of Trypanosoma rhodesiense and enriched in flagellar pocket membrane, was characterized with regard to antigenicity using antibodies raised against purified flagellar pocket membrane. Mild trypsinolysis of flagellar pocket membrane released two small peptides (Mr = 13-16 X 10(3)) separated by chromatofocusing (pI = 6.8 and 5.8) that were antigenic as monitored by fused rocket immunoelectrophoresis. Both of these antigenic peptides were enriched in relative fluorescence when flagellar pocket membrane was prepared from surface labeled (fluorescamine-beta-cyclodextrin) trypanosomes, indicating that cleaved peptides were on the external (luminal) side of the flagellar pocket membrane. More extensive release of fluorescamine labeled flagellar pocket membrane components was affected using mild detergent treatment (0.15% Zwittergent 3-12/0.4% Triton X-100), crossed immunoelectrophoresis separating two prominent antigens was more pronounced after incubation of flagellar pocket membrane with either porcine pancreas phospholipase A2 or umbilical cord sphingomyelinase. The use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subsequent electroblotting to nitrocellulose also revealed two principal flagellar pocket membrane antigens (Mr approximately 60 and 66 X 10(3)), the latter showing greater release after exposure to sphingomyelinase or phospholipase, compared to mild detergent or 50 mM acetate, pH 5.0. Both antigens were glycoprotein as judged by electroblotting and the use of concanavalin A conjugated horseradish peroxidase as probe. Neither flagellar pocket membrane antigen was found to react with monoclonal antibodies prepared against T. rhodesiense variable surface antigen. The use of flagellar pocket membrane in the presence of Freund's complete adjuvant was found to protect mice against challenge infections with either the CP344 clone or uncloned CT Well-come isolate of T. rhodesiense.

The CML-specific P210 bcr/abl protein, unlike v-abl, does not transform NIH/3T3 fibroblasts

The v-abl oncogene of the Abelson murine leukemia virus (A-MuLV) is known to efficiently transform NIH/3T3 fibroblasts in vitro and to cause an acute lymphosarcoma in susceptible murine hosts. The role of its relative, the bcr/abl gene product, in the etiology of human chronic myelogenous leukemia (CML) remains speculative. To assess the transforming properties of the bcr/abl gene product, complementary DNA clones encoding the CML-specific P210 bcr/abl protein were expressed in NIH/3T3 fibroblasts. In contrast to the v-abl oncogene product P160, the P210 bcr/abl gene product did not transform NIH/3T3 cells. Cell lines were isolated that expressed high levels of the P210 bcr/abl protein but were morphologically normal. During the course of these experiments, a transforming recombinant of bcr/abl was isolated which fuses gag determinants derived from helper virus to the NH2-terminus of the bcr/abl protein. This suggests that a property of viral gag sequences, probably myristylation-dependent membrane localization, must be provided to bcr/abl for it to transform fibroblasts.

Cold air challenge in children with asthma

A study was designed to determine the sensitivity and specificity of a cold air bronchial provocation test. A total of 18 children with asthma (mean age 12 years) and 18 normal children (mean age 14 years) were studied. The cold air challenge consisted of a 4 min period of isocapnic hyperventilation of subfreezing air (mean temperature -15 degrees C). In-Induced response in forced expiratory volume in 1 sec (FEV1) expressed as a percentage of predicted normal values was obtained at 4, 6, and 8 min post-challenge. The average response to the cold air was a 27% decrease of FEV1 in asthmatics, which was significantly different from that of the normal children, who showed no statistically significant drop. In both the asthmatic and normal groups, the maximal drop in FEV1 had occurred by the time measurements 4 min post-challenge had been made. At that time, the smallest overlap was observed between normal and asthmatic children. This suggests that the fourth minute post-challenge can be chosen as a cut-off time to distinguish normal from asthmatic children. Considering a decrease of FEV1 greater than 10% as a positive test, the sensitivity of the cold air challenge was 95% and the specificity was 89%.

Unique forms of the abl tyrosine kinase distinguish Ph1-positive CML from Ph1-positive ALL

In the Philadelphia chromosome (Ph1) of chronic myelogenous leukemia (CML), the c-abl gene on chromosome 9 is translocated to bcr on chromosome 22. This results in the expression of a chimeric bcr-abl message that encodes the P210bcr-abl tyrosine kinase. The cells of 10% of acute lymphocytic leukemia patients (ALL) carry a cytogenetically similar Ph1 translocation. We report that Ph1-positive ALL cells express unique abl-derived tyrosine kinases of 185 and 180 kilodaltons that are distinct from the bcr-abl-derived P210 protein of CML. The appearance of the 185/180-kilodalton proteins correlates with the expression of a novel 6.5-kilobase messenger RNA. Thus, similar genetic translocations in two different leukemias result in the expression of distinct c-abl-derived products.

Molecular cloning and serological characterization of an altered c-abl gene product produced in Ph1 CML patients

The reciprocal translocation between human chromosomes 9 and 22, termed the Philadelphia chromosome (Ph1), is observed in more than 90% of patients with chronic myelogenous leukemia. This translocation fuses sequences from a variable distance 5' to the c-abl locus on chromosome 9 to sequences in a breakpoint cluster region (bcr) on chromosome 22. The appearance of the Ph1 chromosome is correlated with the production of a novel 8.7-kb RNA transcript containing both bcr and c-abl sequences as well as with a 210-kd phosphoprotein (p210c-abl) representing non-abl polypeptide sequences fused to c-abl-derived sequences. Antibodies prepared to a number of different c-abl domains and to bcr determinants were employed to characterize the normal and altered c-abl gene products. By combining a variety of cDNA cloning techniques, we have isolated bcr/abl clones representing 8.7 kb of contiguous mRNA sequence.

Overlapping cDNA clones define the complete coding region for the P210c-abl gene product associated with chronic myelogenous leukemia cells containing the Philadelphia chromosome

The Philadelphia chromosome, observed in greater than 90% of patients with chronic myelogenous leukemia, results from a reciprocal translocation between chromosomes 9 and 22. The translocation breakpoint on chromosome 9 occurs near the ABL gene and correlates with the production of a chronic myelogenous leukemia-specific 8.5-kilobase ABL-related mRNA species accompanied by a structurally altered ABL protein (P210c-abl). The N-terminal sequence of the protein is derived from the BCR gene on chromosome 22. We have isolated overlapping cDNA clones from the K-562 cell line corresponding to approximately 8.5 kilobases of mRNA and have sequenced 2550 nucleotides at the 5' end. Our results indicate that the 5' end of the 8.5-kilobase mRNA consists of greater than 400 nucleotides of noncoding sequence that are greater than 80% G + C rich. Based on our sequence analysis, we propose that initiation of translation occurs at nucleotide 471, such that the initial 927 amino acids of P210c-abl are derived from BCR sequences. Our cDNA clones thus define the complete coding sequences for the P210c-abl gene product.

Adrenocortical dysfunction in acute medical illness

To further characterize the adrenocortical response to acute illness, we measured basal and adrenocorticotropic hormone (ACTH)-stimulated 11-deoxycortisol, androstenedione, and dehydroepiandrosterone sulfate (DHEAS). Acutely ill patients had higher ACTH-stimulated 11-deoxycortisol and androstenedione, and decreased basal and ACTH-stimulated androstenedione/cortisol and DHEAS/cortisol ratios. Our data suggest that a shift away from androgen synthesis toward the glucocorticoid pathway occurs in acute illness.

Variable expression of the translocated c-abl oncogene in Philadelphia-chromosome-positive B-lymphoid cell lines from chronic myelogenous leukemia patients

The consistent cytogenetic translocation of chronic myelogenous leukemia (the Philadelphia chromosome, Ph1) has been observed in cells of multiple hematopoietic lineages. This translocation creates a chimeric gene composed of breakpoint-cluster-region (bcr) sequences from chromosome 22 fused to a portion of the abl oncogene on chromosome 9. The resulting gene product (P210c-abl) resembles the transforming protein of the Abelson murine leukemia virus in its structure and tyrosine kinase activity. P210c-abl is expressed in Ph1-positive cell lines of myeloid lineage and in clinical specimens with myeloid predominance. We show here that Epstein-Barr virus-transformed B-lymphocyte lines that retain Ph1 can express P210c-abl. The level of expression in these B-cell lines is generally lower and more variable than that observed for myeloid lines. Protein expression is not related to amplification of the abl gene but to variation in the level of bcr-abl mRNA produced from a single Ph1 template.

The association of distinct acid phosphatases with the flagella pocket and surface membrane fractions obtained from bloodstream forms of Trypanosoma rhodesiense

Cell fractionation of bloodstream Trypanosoma rhodesiense, using isopycnic sucrose gradient centrifugation, reveals acid phosphatase activities against a range of substrates to be associated, to varying degrees, with subcellular particle populations identified as derived from flagella pocket membrane and surface membrane. Using these same substrates (alpha and beta glycerophosphate, p-nitrophenyl phosphate and glucose-6-phosphate) at least two distinct acid phosphatase activities can be distinguished. One is thermolabile (approximately 80% inactivated after 30 min. at 60 degrees C), sensitive to tartrate (50% inhibited at 1.8 mM Na tartrate) with a pH optimum approximately 4.5 and appears to exhibit little substrate preference. The other acid phosphatase is relatively heat stable (approximately 30% inactivated), insensitive to tartrate (greater than 5.0% inhibited using 1.8 mM Na tartrate) exhibits a somewhat higher pH optimum (approximately 6.0) and is more substrate specific (6X more active toward glucose-6-PO4 than beta-glycerophosphate). Further cell fractionation experiments reveal 85% of the tartrate sensitive acid phosphatase to be associated with flagella pocket membrane and to account for 80% of the organisms hydrolytic activity toward beta-glycerophosphate. The tartrate resistant acid phosphatase however, has a much less exclusive localization being almost equally distributed between surface membrane (40%) and flagella pocket membrane (60%).

Emergency pediatric tracheostomy: a usable technique and model for instruction

Tracheostomies, although rarely performed, may be necessary in cases in which a cricothyrotomy is precluded by the small size of the cricothyroid space in infants and small children, when there is a high-grade upper airway obstruction, or when massive neck swelling or laryngeal fractures obscure the cricothyroid landmarks. A new technique for emergency pediatric tracheostomy and a model for practicing the procedure in cats has been developed. The technique uses a finder needle and a saline-filled syringe to locate the small and poorly defined trachea. Free-flowing saline or aspirated air bubbles indicate entrance of the locator needle into the tracheal lumen. A stabbing incision is made lateral to and against the needle, the stoma is spread, and an endotracheal tube is introduced. Kittens weighing 1,000 g to 1,500 g have a tracheal diameter of 5.5 mm to 6.0 mm, equivalent to a child less than 1 year old. Cats in the 2,000-g to 3,000-g range approximate the tracheal size for an older child. Either recently killed or anesthetized cats may be used. Using this model, emergency physicians can become more proficient in performing tracheostomies rapidly on small subjects. This technique, however, has not been studied in human beings of the pediatric age group.

Acute myocardial infarction among Navajo Indians, 1976-83

We found that from 1976 through 1983 the incidence of acute myocardial infarction (AMI) diagnosed among Navajo Indians remained low (0.5 per 1,000 persons age 30 years or more), although the incidence in women appears to be climbing. Navajo AMI patients are more likely to be hypertensive and diabetic than age- and sex-matched patients with gallbladder disease. Twenty-four per cent die within one month of AMI.

Activation of a heat-stable cytolytic protein associated with the surface membrane of Naegleria fowleri

Surface membrane-enriched fractions of Naegleria fowleri obtained after isopycnic centrifugation experiments contain a potent cytolytic activity as determined by hemolysis and 51Cr release assays. This surface membrane cytolysin was unaffected by a treatment at 75 degrees C for 30 min and accounted for 70 to 90% of cytolysis by whole-cell lysates of amoebae. This heat resistance as well as intimate membrane association distinguished the surface membrane cytolytic activity from a second heat-labile cytolytic activity which appears to be latent within lysosomes. The surface membrane cytolysin was found to be specifically activated by diluted samples of lysosomal fractions. The possible role of this surface membrane cytotoxin in the pathogenicity of N. fowleri is discussed.

Subcellular distribution of hydrolases in Naegleria fowleri

The presence and particle association of various hydrolytic enzymes in Naegleria fowleri has been studied in whole cell extracts of trophozoites in an effort to establish authentic markers for surface membrane and lysosomal components. Evidence from the experiments reported here indicates that in N. fowleri a) acid proteinase, N-acetylglucosaminidase, and acid phosphatase are associated with cytoplasmic granules closely resembling lysosomes; b) 5'-nucleotidase is associated with the surface membrane, probably on the external surface; c) aspartate aminotransferase is associated with mitochondria; d) alpha-D-glucosidase and an aminopeptidase have bimodal distributions, activity being associated with both the surface membrane and lysosomal particles.

The self-care behavior inventory: a model for behavioral instrument development

The Self-Care Behavior (SCB) Inventory was developed as part of a long-term study of self-care practices of persons who have multiple sclerosis (MS) in Denmark. The universe of behaviors regarding the physical, social, emotional, environmental, and spiritual aspects of coping with the illness was ascertained by informal and formal interviews. Respondents were asked not only what behavior was performed, but also who performed it, how it was performed, why, when, and where it was performed, and where the knowledge to perform the behavior in this manner was acquired, such as a lay-referral network, physician, social worker, spouse, or media. The inventory went through a series of drafts and pre-tests, resulting in a final version that met criteria for validity and reliability. The model presented for the development of the SCB Inventory can be useful for designing behavioral inventories and assessment tools for other chronic conditions such as arthritis, epilepsy, and diabetes.

A high affinity Ca2+-dependent ATPase in the surface membrane of the bloodstream stage of Trypanosoma rhodesiense

Addition of Ca2+ (0.01-1 mM) to a standard Trypanosoma rhodesiense Mg2+-ATPase assay failed to elicit any increase in activity. However, in the absence of externally added Mg2+ and using calcium-EGTA or calcium-CDTA to precisely maintain free metal ion concentration, it was possible to measure a specific Ca2+-ATPase. Cell fractionation studies revealed this ATPase to be predominantly associated with subcellular particles having an equilibrium density of 1.22 g cm-3 and identified as surface membrane. Using a discontinuous sucrose gradient, a surface membrane enriched (SME) fraction, only slightly contaminated with mitochondria as judged by dichlorophenolindophenol-linked alpha-glycerophosphate dehydrogenase activity, was prepared. The SME fraction exhibited Ca2+-ATPase activity, using 200 nM free Ca2+, of 90 and 21 mU mg-1 protein, respectively, using CDTA and EGTA as buffering ligands. This latter result was most unexpected and indicated that the Ca2+-ATPase, in addition to having no Mg2+ requirement, was inhibited by submicromolar levels of Mg2+. The Ca2+-ATPase was found to have a K0.5 = 128 +/- 22 nM free Ca2+, the response to increasing Ca2+ concentration displaying an extremely high degree of co-operativity (Hill number (nH) = 4.9). The enzyme was found to be highly substrate-specific for ATP with K0.5 = 6.2 +/- 0.61 microM ATP. A Hill plot of the reaction velocity as a function of ATP concentration indicated two substrate binding sites (nH = 1.55). A range of potential modulators of ATPase activity were investigated, with only vanadate (V2O3-8) having any effect: 47% inhibition at 5.0 microM. The Ca2+-ATPase was unaffected by the calmodulin antagonists chlorpromazine (50 microM) and trifluoperazine (50 microM), whilst addition of calmodulin failed to produce any stimulation of activity. It is concluded that the kinetic properties of this ATPase are compatible with a potential role in the regulation of intracellular Ca2+ in bloodstream T. rhodesiense.

The presence of alpha-glycerophosphate dehydrogenase (NAD+-linked) and adenylate kinase as core and integral membrane enzymes respectively in the glycosomes of Trypanosoma rhodesiense

A subcellular fraction enriched 12 times in glycosomes (NAD+-linked alpha-glycerophosphate dehydrogenase) and devoid of detectable contamination from other subcellular components, was prepared from bloodstream Trypanosoma rhodesiense. Using a method employing exposure to toluene as a means of studying normally latent glycosomal enzymes, and phospholipase A2 as a membrane probe, the association of adenylate kinase and alpha-glycerophosphate dehydrogenase with the glycosome was studied. The normally latent glycerophosphate dehydrogenase (NAD+ linked), it is proposed, is an intraglycosomal enzyme having no membrane association, but bound to the core by weak ionic linkages. As such it is possible to release the enzyme from permeable (toluene treated) glycosomes using Cl-, with a resulting 4-fold increase in the Km for dihydroxyacetone phosphate. The presence of Cl- also stimulates an increase in specific activity, but this is observed before any release of enzyme. In contrast adenylate kinase, a non-latent glycosomal enzyme, is clearly membrane associated, the use of phospholipase A2 revealing an absolute dependence on phospholipid for activity. Restoration of activity appears to specifically require phosphatidyl choline and to be co-operative in nature (nH = 1.56). It is proposed that adenylate kinase is an integral glycosomal membrane enzyme, probably affecting the control of intra-glycosomal ADP/ATP levels.

A multicomponent hemolytic system in the pathogenic amoeba Naegleria fowleri

A hemolytic activity associated with postnuclear supernatant fractions of Naegleria fowleri has been partially characterized in an attempt to isolate cytolytic molecules that may participate in naeglerial cytopathogenicity. Hemolysis by naeglerial postnuclear supernatant fractions was sensitive to heat and trypsin hydrolysis, and was inhibited by divalent cations. The majority of the hemolytic activity was nonlatent and associated with a particle fraction sedimenting at 48,000 X g (maximum) for 1 h. This particle-associated hemolytic activity appears to be membrane associated, as high salt concentration, chelating agents, and pH extremes were ineffective in solubilizing the hemolytic activity, whereas treatment with 0.15% Zwittergent 3-12, a dipolar ionic detergent, results in 98% release of the sedimentable hemolysin. The sigmoidal nature of the progress curve of postnuclear supernatant hemolysis, as well as synergistic interactions between fractions of amoebal whole cell extracts, suggests that the hemolytic activity has a multicomponent nature, with at least two and possibly three components participating in the hemolytic event. The significance of these findings in the context of naeglerial cytopathogenicity is discussed.

Midazolam for upper gastrointestinal endoscopy

A water-soluble benzodiazepine, midazolam, was used in 400 patients undergoing upper gastrointestinal endoscopy, alone or in combination with pentazocine and compared with 68 patients given diazepam (Valium). In the last 200 patients the endoscopist used midazolam without the presence of an anaesthetist. The absence of injection pain was the most notable feature of midazolam. The degree of co-operation was similar in all groups but the operating conditions were significantly better when midazolam was combined with pentazocine. There was no significant difference in recovery times between the groups as assessed by the pegboard test. Midazolam is an acceptable alternative to diazepam for upper gastrointestinal endoscopy.

Long terminal repeats of human T-cell leukaemia virus II genome determine target cell specificity

Human T-cell leukaemias and lymphomas associated with the human T-cell leukaemia viruses (HTLV) are invariably neoplasms of cells with mature T-lymphocyte phenotype. Epstein-Barr virus-transformed B- lymphoycte lines which are productively infected with HTLV may be isolated from patients with HTLV malignancies, but no non-lymphoid tissues seem to be involved. Here, to investigate the basis for this tissue specificity, we introduced type II HTLV (HTLV-II) into a variety of human cells by infection and also by transfection of recombinant genomes. We found no HTLV-II expression in non-lymphoid tissues although expression and correct initiation of transcription was observed in B and T lymphocytes. Our results using recombinant genomes indicate that the restriction of expression is at least partly due to cis-acting functions of the long terminal repeats which lie at each end of the HTLV genome.

Evidence for lipid-protein interactions in the attachment of antigens to a low-density membrane fraction isolated from Trypanosoma rhodesiense

A putative Trypanosoma rhodesiense flagella pocket membrane fraction (FPM) was previously found to possess a range of antigenic components that were released after exposure to a detergent mixture containing 0.1% Zwittergent 3-12 and 0.4% Triton X-100. In the present investigation, and effort was made to determine the role of membrane lipid in binding FPM antigens, using phospholipases A2 and C as membrane probes. Exposure to the former was notable for the release of one antigen in particular that was only poorly extracted with the above detergents. Evidence was obtained suggesting that this release was not due to the detergent action of degradation products formed by the action of phospholipase A2 on membrane phospholipids. This phospholipase-released antigen, as were most other FPM antigens, was a glycoprotein, although the carbohydrate sequences do not appear to influence antigenicity. It was also possible to demonstrate the presence of a group of three cross-reacting FPM antigens that partitioned as hydrophobic membrane proteins by using Triton X-114 extraction. This was in contrast to the predominantly hydrophilic nature of most other FPM antigens.