A drug-responsive and protease-resistant peripheral NADH oxidase complex from the surface of HeLa S cells

Our laboratory described a ca. 34-kDa protein of the HeLa S cell surface that bound an antitumor sulfonylurea N-(4-methylphenylsulfonyl)-N'-(4-chlorophenyl) urea (LY181984) with high affinity and that exhibited NADH oxidase and protein disulfide-thiol interchange activities also inhibited by LY181984. The quinone site inhibitor 8-methyl-N-vanillyl-6-noneamide (capsaicin) also blocked these same enzymatic activities. Using capsaicin inhibition as the criterion, the drug-responsive oxidase was released from the surface of HeLa S cells and purified. The activity of the released capsaicin-inhibited oxidase was resistant to heating at 50 degrees C and to protease digestion. After heating and proteinase K digestion, the activity was isolated in >90% yield by FPLC as an apparent 50- to 60-kDa multimer. Final purification by preparative SDS-PAGE yielded a capsaicin-inhibited NADH oxidase activity of a specific activity indicative of >500-fold purification relative to the plasma membrane. The final activity correlated with a ca. 34-kDa band on SDS-PAGE. Matrix-assisted laser desorption mass spectroscopy as well as reelectrophoresis of the 34-kDa band indicated that the ca. 34-kDa material was a stable mixture of 22-, 17-, and 9.5-kDa components which occasionally migrated as a ca. 52-kDa complex. The purified complex tended to multimerize and formed insoluble 10- to 20-nm-diameter amyloid rods. The components of the purified 34-kDa complex were blocked to N-terminal amino acid sequencing and were resistant to further protease digestion. After multimerization into amyloid rods, the protein remained resistant to proteases even under denaturing conditions and to cyanogen bromide either with or without prior alkylation.

Effects of sensor selection on exercise stroke volume in pacemaker dependent patients

The effects of sensor selection and sensor blending on the cardiovascular response to graded exercise was evaluated in 10 patients (age 74 +/- 2 yrs; 7 men and 3 women) implanted with a dual sensor rate adaptive VVIR pacemaker (Vitatron Topaz model 515). Patients underwent three graded exercise tests (GXT) with sensor programming randomly assigned. For a given graded exercise text the pacemaker was programmed into activity sensing (ACT), QT sensing, or dual sensing (ACT = QT). Data were recorded at rest and during each stage of the graded exercise text. Oxygen uptake (VO2) was measured continuously using a Q Plex I system. Heart rate (HR), stroke volume (SV), and cardiac output (Qc) were measured by impedance cardiography. Systolic time intervals were calculated from simultaneous recordings of the ECG, phonocardiogram, and the impedance cardiogram. In response to the GXT no differences in peak VO2 were observed across the three sensor settings. Regardless of the sensor setting Qc increased linearly with each increment in VO2. The HR response to ACT only pacing was significantly higher than in the other two pacing conditions. During ACT only pacing SV failed to rise in response to exercise. The increased exercise Qc during QT and ACT = QT pacing were mediated by significant increases in both HR and SV. The QT and dual pacing conditions were also associated with longer diastolic filling times. The data indicate that the mechanisms responsible for the increase Qc during exercise were different for ACT versus ACT = QT or QT sensor-driven pacing.

Survival of children in Cape Town known to be vertically infected with HIV-1

OBJECTIVE

To determine the survival patterns of children in Cape Town known to be vertically infected with HIV.

DESIGN

Retrospective record review of children diagnosed with symptomatic HIV infection during the period 1 December 1990-31 May 1995.

SETTING

Hospitals in the Cape Town metropolitan area.

PATIENTS

193 children were known to be vertically HIV-infected. HIV diagnosis was based on the following criteria: two positive HIV enzyme-linked immunosorbent assays (ELISAs) in children older than 15 months and a positive ELISA together with a positive polymerase chain reaction (PCR) in younger children. The mothers of the children were known to be HIV-positive. On the basis of the presenting clinical findings children were assigned to a disease severity category (A, B or C) according to the Centers for Disease Control and Prevention (CDC)'s 1994 revised classification system for HIV infection in children.

OUTCOME MEASURES

Survival was analysed according to the Kaplan-Meier method. Survival time was defined as the length of time between clinical diagnosis of HIV and death or last contact with the health services. Mortality risk in relation to specific variables at diagnosis such as age and clinical manifestations was determined by calculation of odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

The median age at diagnosis was 5 months; 72% of children were aged less than 1 year at diagnosis. According to the CDC clinical classification, 47 (24%) fell into category A, 111 (58%) into category B and 35 (18%) into category C. Of the 193 patients 85 (44%) were alive at the time of review, 65 (34%) had died and 43 (22%) were lost to follow-up. Risk of death was significantly associated with age less than 6 months (OR 4.7, CI 2.1-10.3) and severe disease, i.e. CDC category C (OR 2.7; CI 1.1-6.9) at time of diagnosis. The median survival for all the children from time of diagnosis was 32 months. Infants diagnosed before 6 months of age had significantly shorter median survival (10 months) compared with 36 months for those diagnosed at 7-12 months of age. For the children over the age of 12 months the cumulative proportion surviving at 48 months was 78%. Children with severe disease (category C) had a median survival of 21 months, significantly lower than that in category B (32 months). For the children in category A the cumulative proportion surviving at 48 months was 66%.

CONCLUSION

The median survival of children with HIV was 32 months from time of diagnosis, and survival was influenced by age and disease severity.

Reboxetine in the treatment of depression: Early clinical experience in the UK

The potential efficacy and tolerability of new antidepressants can best be assessed through randomized controlled trials (RCTs). However, the patient population in antidepressant studies is a highly selected group, so the results from such studies may not be applicable to routine clinical practice. This paper describes a questionnaire survey of senior psychiatrists in the UK aimed at evaluating early clinical experience with reboxetine, a new, selective noradrenaline re-uptake inhibitor (selective NRI) recently introduced in the UK for the treatment of depression. Psychiatrists were asked for details of their experience with reboxetine in depression, illustrated with representative case histories. The spontaneous adverse events reported to the Medicines Control Agency (MCA) were also reviewed. Information was collected on over 250 patients, 50% of whom had responded sub-optimally to previous physical treatments for this current episode; over 50% had co-morbid psychiatric disorders, and 29.1% had coexisting physical illness. Most of the patients were treated with 8 mg/day of reboxetine. The overall clinical response to reboxetine, as judged by the treating doctor, was considered 'good' in over 65% of patients. Three-quarters of them showed 'good/very good' improvement in their symptoms; the same proportion achieved a 'good/very good' improvement in activities of daily living. Two-thirds of patients did not report any troublesome side-effects, the profile being consistent with that seen in RCTs. Analysis of spontaneous adverse events reported to the MCA has not as yet revealed any surprises. Early clinical experience with reboxetine in routine practice is encouraging. Efficacy, tolerability and simple dosing appear to be particular benefits to patients. Consistent with data from RCTs involving reboxetine, recovery of function accompanies symptomatic improvement, which may be related to the selective effects of the drug on noradrenaline.

Data and information requirements for the Department of Veterans Affairs resource allocation systems

The department of Veterans Affairs (VA) uses a global budgeting process to allocate congressionally appropriated resources to provide medical care to veterans. The Department of Veterans Affairs has developed this process to accommodate the effects of changes in pure inflation, workload, and cost per unit of work in forecasting operating dollars required for facility global budgets. In 1990, VA began shifting to a new method of allocating its global budget called Resource Planning and Management (RPM), based on a capitated system. Facilities receive resources according to their unit costs and the number and type of patients they are expected to serve. A key characteristic of any global budgeting information system is flexibility. The VA information system accesses the portion of each patients's care that is provided at every facility and aggregates this information across all facilities to create a single prorated patient record; the system reconstructs prior years of data into the new patient-centered format to forecast workload. No other health care system in the United States pays for and directly provides such a diverse set of services for such a large population as does VA. Nevertheless, many of the problems VA faces are similar to those of other providers and insurers.

Potent human immunodeficiency virus type 1 protease inhibitors that utilize noncoded D-amino acids as P2/P3 ligands

Noncoded D-amino acids have been designed to replace the quinaldic amide-asparaginyl moiety (P2/P3 ligand) found in several potent human immunodeficiency virus (HIV) protease inhibitors such as LY289612. The substituted nitrogen, optimally an N-methanesulfonyl moiety, served as a CH2CONH2 (asparagine side chain mimic), while the amino acid side chain became the backbone and P3 ligand of these novel inhibitors. Compounds derived from S-aryl-D-cysteine proved to be potent HIV protease inhibitors which also exhibited potent whole cell antiviral activity. Oxidation of the cysteines to the sulfoxide or sulfone oxidation states resulted in significant improvements in potency. For example, the compound derived from N-(methyl-sulfonyl)-2-S-naphthylcysteine sulfone, 17c, was a 3.5 nM inhibitor of HIV protease which inhibited the spread of virus in MT4 cells with an IC50 = 4.3 nM. Compounds 17c,g,i were found to be orally bioavailable in a rat model.

HIV/AIDS education for nurses in Poland

Funded by an agreement with the World AIDS Foundation, a team of American and Polish healthcare professional was established to provide expert and timely training on HIV/AIDS course for nurses was conducted in Gdansk, Poland. The course identified significant professionals concerns of Polish nurses, including fear of infection, discomfort with male sexuality, and lack of information about drug users. Precourse and postcourse evaluations demonstrated significant changes in level of comfort during discussions of sensitive topics and improvement in instructional self-confidence.

In vitro and in vivo antitumor activity of a chimeric anti-CD19 antibody

Mouse monoclonal antibodies to CD19 detect an antigenic determinant expressed exclusively on the surface of B lymphocytes, and have previously been shown to be potentially useful therapeutic reagents for human B cell lymphoma. We report the production and characterization of a mouse/human chimeric antibody, cCD19, with potent in vivo antitumour activity. The genes encoding the variable domains for heavy (VH) and light (VL) chains were subcloned into eukaryotic expression vectors containing human constant region genes (IgG1 and kappa), and co-transfected into non-secreting Sp2/0 mouse myeloma cells. Intraperitoneal administration of cCD19 produced inhibition of growth of subcutaneous CD19+ Sultan human B lymphoma tumours in scid/scid mice. When the antibody was administered 18 and 20 days after subcutaneous tumour inoculation, an approximately 30% reduction in tumour size was noted by day 29. cCD19 faithfully mimicked the in vitro binding characteristics of mCD19 as (a) the chimeric antibody was shown by flow cytometry to bind exclusively to cell lines that expressed CD19, (b) cCD19 was able to inhibit the binding of mCD19 on CD19+ cells completely and (c) the affinity of binding of the two antibodies was not significantly different [Ka = (2.03 +/- 1.5) x 10(8)]. In bio-distribution studies, up to 14.8% of the total injected antibody dose per gram of tissue was localized in CD19+ Sultan tumours at 24 h approximately, 14.4% was present in the tumors at 48 h, and about 13.7% at 72 h. These levels were comparable to mCD19 administered in the same fashion. cCD19 conjugated to idarubicin was specifically and strongly cytotoxic to CD19+ cells cultured in vitro, and demonstrated an IC50 of 0.17 microM, similar to that of mCD19 (0.32 microM) and approximately 14-fold greater than the IC50 of free idarubicin. The specific cytotoxic capacity of cCD19 and its likely reduced immunogenicity suggest that it may potentially be of use in the treatment of refractory B cell lymphoma in humans.

Solvation of platinum anti-cancer drugs in methanol-water mixtures

Solubilities and transfer chemical potentials of carboplatin, cisplatin, iproplatin, and several related platinum complexes have been determined in methanol-water mixtures. The range of solvation behaviour is discussed in relation to possible oral administration of complexes of this type.

Harvesting and enrichment of hematopoietic progenitor cells mobilized into the peripheral blood of normal donors by granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF: potential role in allogeneic marrow transplantation

To explore the use of stem/progenitor cells from peripheral blood (PB) for allogeneic transplantation, we have studied the mobilization of progenitor cells in normal donors by growth factors. Normal subjects were administered either granulocyte-macrophage colony-stimulating factor (GM-CSF) at 10 micrograms/kg/d, or G-CSF at 10 micrograms/kg/d, or a combination of G- and GM-CSF at 5 micrograms/kg/d each, administered subcutaneously for 4 days, followed by leukapheresis on day 5. Mononuclear cells expressing CD34 (CD34+ cells) were selectively enriched by affinity labeling using Dynal paramagnetic microspheres (Baxter Isolex; Baxter Healthcare Corp, Santa Ana, CA). The baseline CD34+ cells in peripheral blood before mobilization was 0.07% +/- 0.05% (1.6 +/- 0.7/microL; n = 18). On the fifth day after stimulation (24 hours after the fourth dose), the CD34+ cells were 0.99% +/- 0.40% (61 +/- 14/microL) for the 8 subjects treated with G-CSF, 0.25% +/- 0.25% (3 +/- 3/microL, both P < .01 v G-CSF) for the 5 subjects administered GM-CSF, and for the 5 subjects treated with G- and GM-CSF, 0.65% +/- 0.28% (41 +/- 18/microL, P < .5 v GM-CSF). Parallel to this increase in CD34+ cells, clonogenic assays showed a corresponding increase in CFU-GM and BFU-E. The total number of CD34+ cells collected from the G-CSF group during a 3-hour apheresis was 119 +/- 65 x 10(6) and was not significantly different from that collected from the group treated with G- and GM-CSF (101 +/- 35 x 10(6) cells), but both were greater than that from the group treated with GM-CSF (12.6 +/- 6.1 x 10(6); P < .01 for both comparisons). Analysis of the CD34+ subsets showed that a significantly higher percentage of cells with the CD34+/CD38- phenotype is found after mobilization with G- and GM-CSF. In the G-CSF group, immunomagnetic selection of CD34+ cells permitted the enrichment of the CD34+ cells in the apheresis product to 81% +/- 11%, with a 48% +/- 12% yield and to a purity of 77% +/- 21% with a 51% +/- 15% recovery in the G- and GM-CSF group. T cells were depleted from a mean of 4.5 +/- 2.0 x 10(9) to 4.3 +/- 5.2 x 10(6) after selection, representing 99.9% depletion. We conclude that it is feasible to collect sufficient numbers of PB progenitor cells from normal donors with one to two leukapheresis procedures for allogeneic transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of chickens and pheasants as sentinels for eastern equine encephalitis and St. Louis encephalitis viruses in Florida

Pheasants and chickens were compared as sentinels for monitoring the transmission of arboviruses of public health significance in Florida during 1991-93. Results suggest that pheasants are better sentinels for eastern equine encephalitis (EEE) virus. They detected virus transmission 3-6 weeks earlier in epizootic years, 2-4 times more frequently during the season, and twice as many birds within a flock seroconverted during a given week. Pheasants detected virus transmission at 2 sites during 2 interepizootic years when chickens failed. Although pheasants detected St. Louis encephalitis (SLE) virus activity somewhat later than did chickens, they had greater seroconversion rates than did chickens. Although both bird species can be used to monitor EEE and SLE viruses, pheasants are more sensitive than chickens as sentinels for EEE virus and as sensitive as chickens as sentinels for SLE virus.

Chimeric (mouse/human) anti-colon cancer antibody c30.6 inhibits the growth of human colorectal cancer xenografts in scid/scid mice

The mouse monoclonal antibody, m30.6 (IgG2b), detects an antigenic determinant expressed predominantly on the surface of colorectal adenocarcinoma cells and has been shown previously to be a potentially useful therapeutic and diagnostic reagent for human colon cancer. We report the production and characterization of a mouse/human chimeric antibody, c30.6, with potent in vitro and in vivo antitumor activity. The genes encoding the variable domains for heavy and light chains were amplified by thermal cycling using degenerate oligonucleotide primers complementary to conserved immunoglobulin framework sequences. The gene segments were sequenced, subcloned into eukaryotic expression vectors containing human constant region genes (IgG1 and kappa), and cotransfected into nonsecreting Sp2/0 mouse myeloma cells. There were significant differences in the biological activities of the murine and chimeric antibodies. The i.p. administration of c30.6 but not of m30.6 produced a marked growth inhibition of s.c. 30.6+ COLO 205 tumors in scid/scid mice (approximately 40% reduction in tumor size, measured 21 days after tumor inoculation). Reduced tumor growth was not due to altered binding characteristics of c30.6 because: (a) the chimeric antibody was shown by flow cytometry to bind exclusively to cell lines that expressed the 30.6 determinant; (b) c30.6 was able to completely inhibit the binding of m30.6 on 30.6+ cells; and (c) the affinity of binding of the two antibodies was the same (Ka, approximately 1.50 x 10(8)). Up to 15% of the total injected antibody dose/g tissue was localized in 30.6+ tumors at 24 h, approximately 13% was present in the tumors at 48 h, and approximately 10% was present at 72 h. Furthermore, c30.6 demonstrated a shorter circulating half-life (53 h; m30.6, 72 h) when given i.p. to C57BL6 x BALB/cF1 mice. Unlike m30.6, c30.6 was also strongly active in antibody-dependent cell-mediated cytotoxicity against a range of 30.6+ tumor target cells in vitro. Up to 80% specific 51Cr release was achieved using either freshly isolated human peripheral blood mononuclear cells or 2-day-old interleukin 2-stimulated human peripheral blood mononuclear cells as effectors. The enhanced antitumor activity of c30.6 suggests that it might be a useful immunotherapeutic reagent for colorectal carcinoma.