MRI contrast agent concentration and tumor interstitial fluid pressure

The present work describes the relationship between tumor interstitial fluid pressure (TIFP) and the concentration of contrast agent for dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). We predict the spatial distribution of TIFP based on that of contrast agent concentration. We also discuss the cases for estimating tumor interstitial volume fraction (void fraction or porosity of porous medium), ve, and contrast volume transfer constant, K(trans), by measuring the ratio of contrast agent concentration in tissue to that in plasma. A linear fluid velocity distribution may reflect a quadratic function of TIFP distribution and lead to a practical method for TIFP estimation. To calculate TIFP, the parameters or variables should preferably be measured along the direction of the linear fluid velocity (this is in the same direction as the gray value distribution of the image, which is also linear). This method may simplify the calculation for estimating TIFP.

Helicobacter pylori infection in patients with selective immunoglobulin a deficiency

Selective immunoglobulin A (IgA) deficiency (IgAD) is the most common primary immunodeficiency in the western world. The aim of the study was to investigate the prevalence and clinical characteristics of Helicobacter pylori-infected dyspeptic patients with IgAD. Case samples were drawn from all subjects ≥ 12 years of age (n = 104729) who had undergone serum total IgA measurements during 2004-14 for any reason at Leumit Healthcare Services (Israel) and had serum total IgA < 0·07 g/l. The control group was comprised of a random sample of remaining patients with a case-control ratio of 10 controls for each case. The dyspeptic diseases were identified and retrieved from Leumit Health Care Services electronic database using specific ICD-9-CM diagnostic codes. The case group included 347 subjects and the control group 3470 subjects. There were no significant differences in the prevalence of patients with dyspepsia [84 (24·2%) versus 821 (23·6%) for cases and controls, respectively]. Additionally, there was no difference in a proportion of dyspeptic H. pylori-positive subjects [59 (17·1%) versus 524 (15·1%)] between the case and control groups. Only 59 (17%) among the 347 IgAD patients underwent gastroscopy. A significantly larger proportion of case subjects experienced several forms of gastritis [13 (61·9%) versus 38 (21·6%), P < 0·001), duodenal ulcers [seven (33·3%) versus 19 (10·8%); P = 0·01] and nodular lymphoid hyperplasia (NLH) [two (9·5%) versus none; P = 0·011]. IgAD is not associated with increased prevalence of H. pylori-associated dyspepsia; nevertheless, H. pylori-infected dyspeptic IgAD subjects experience more EGD-proved gastritis, duodenal ulcers and NLH.

Interstitial hydraulic conductivity and interstitial fluid pressure for avascular or poorly vascularized tumors

A correct description of the hydraulic conductivity is essential for determining the actual tumor interstitial fluid pressure (TIFP) distribution. Traditionally, it has been assumed that the hydraulic conductivities both in a tumor and normal tissue are constant, and that a tumor has a much larger interstitial hydraulic conductivity than normal tissue. The abrupt transition of the hydraulic conductivity at the tumor surface leads to non-physical results (the hydraulic conductivity and the slope of the TIFP are not continuous at tumor surface). For the sake of simplicity and the need to represent reality, we focus our analysis on avascular or poorly vascularized tumors, which have a necrosis that is mostly in the center and vascularization that is mostly on the periphery. We suggest that there is an intermediary region between the tumor surface and normal tissue. Through this region, the interstitium (including the structure and composition of solid components and interstitial fluid) transitions from tumor to normal tissue. This process also causes the hydraulic conductivity to do the same. We introduce a continuous variation of the hydraulic conductivity, and show that the interstitial hydraulic conductivity in the intermediary region should be monotonically increasing up to the value of hydraulic conductivity in the normal tissue in order for the model to correspond to the actual TIFP distribution. The value of the hydraulic conductivity at the tumor surface should be the lowest in value.

Quantum-classical transition and quantum activation of ratchet currents in the parameter space

The quantum ratchet current is studied in the parameter space of the dissipative kicked rotor model coupled to a zero-temperature quantum environment. We show that vacuum fluctuations blur the generic isoperiodic stable structures found in the classical case. Such structures tend to survive when a measure of statistical dependence between the quantum and classical currents are displayed in the parameter space. In addition, we show that quantum fluctuations can be used to overcome transport barriers in the phase space. Related quantum ratchet current activation regions are spotted in the parameter space. Results are discussed based on quantum, semiclassical, and classical calculations. While the semiclassical dynamics involves vacuum fluctuations, the classical map is driven by thermal noise.

Phenomenological model of interstitial fluid pressure in a solid tumor

Tumor interstitial fluid pressure (TIFP) has the potential to predict tumor response to nonsurgical cancer treatments, including radiation therapy. At present the only quantitative measures available are of limited use, since they are invasive and yield only point measurements. We present the mathematical framework for a quantitative, noninvasive measure of TIFP. The model describes the distribution of interstitial fluid pressure in three distinct tumor regions: vascularized tumor rim, central tumor region, and normal tissue. A relationship between the TIFP and the fluid flow velocity at the periphery of a tumor is presented. This model suggests that a measure of fluid flow rate from a tumor into normal tissue reflects TIFP. We demonstrate that the acquisition of serial images of a tumor after the injection of a contrast agent can provide a noninvasive and potentially quantitative measure of TIFP.

Vibrational relaxation and dephasing of Rb2 attached to helium nanodroplets

The vibrational wave-packet dynamics of diatomic rubidium molecules (Rb(2)) in triplet states formed on the surface of superfluid helium nanodroplets is investigated both experimentally and theoretically. Detailed comparison of experimental femtosecond pump-probe spectra with dissipative quantum dynamics simulations reveals that vibrational relaxation is the main source of dephasing. The rate constant for vibrational relaxation in the first excited triplet state 1(3)Σ(g)+ is found to be constant γ ≈ 0.5 ns(-1) for the lowest vibrational levels v ≲ 15 and to increase sharply when exciting to higher energies.

Serum inflammatory cytokines, complement components, and soluble interleukin 2 receptor in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic autoimmune liver disease characterized by selective destruction of the intrahepatic bile ducts and highly specific serum anti-mitochondrial autoantibodies (AMA). Several studies have attempted to determine the cytokine pattern characterizing PBC, yet no definitive data have been gathered. The present study was designed to evaluate pro-inflammatory cytokines (IL-1beta, IL-6, TNFalpha), soluble IL-2 receptor (sIL-2R, e.g. soluble CD25), and complement components (C1q, C3, factor B, properdin) levels in sera from 84 patients with PBC and 41 controls. PBC was characterized by significantly higher levels of all pro-inflammatory cytokines when compared to controls; these included IL-1beta (433.3 +/- 13.2 vs. 316.6 +/- 14.7 pg/ml, P < 0.001), IL-6 (701 +/- 17.4 vs. 158 +/- 22.5 pg/ml, P < 0.001), TNFalpha (3.38 +/- 0.6 pg/ml vs. undetectable, P = 0.001), and sIL-2R (1527.1 +/- 106 vs. 566.4 +/- 28.7 U/ml, P < 0.001). Similarly, all complement components were also significantly higher in PBC compared to control sera. In conclusion, PBC sera manifest higher levels of sIL-2R and complement components and this may reflect a perpetuated immune activation. As expected, we also report that all major pro-inflammatory cytokine levels are enhanced in PBC. Further longitudinal analyses could demonstrate a correlation between these markers and disease stage or inflammatory activity, to predict histological staging, disease activity, and response to treatment.

Establishment and characterization of a new leukaemic T-cell line (Peer) with an unusual phenotype

We report the isolation and establishment in continuous culture of a human lymphoid cell line (Peer) from a case of T-leukemia. The Peer cell line lacks some typical cell-surface properties of T cells, namely sheep erythrocyte rosette formation and reactivity with two anti-T-cell sera, but has focal acid phosphatase and does express two other T-cell antigens, one defined by a monoclonal antibody, the other related to a T-cell subset (TH2). The cells are negative for B-cell markers (SmIg or cytoplasmic mu Fcgamma and C3 receptors, mouse erythrocyte rosettes) and EBV (EBNA). In addition, the Peer cell does not possess the typical phenotypic markers of "non-B, non-T" leukemia: cALL and Ia-like antigens, and the cytoplasmic hexosaminidase isoenzyme I, but is positive for terminal deoxynucleotidyl transferase by enzymatic and immunofluorescent criteria. The cell line requires exogenous L-asparagine for adequate growth in culture, a property known to be characteristic of certain T cells but not of B cells. The Peer cell line appears to have a maturation arrest at a developmental stage intermediate between the cortical thymocyte and a mature T-cell subset and to have lost some T-cell differentiation features.

Hyposialated 185 kDa CD45RA+ molecules attain a high concentration in B lymphoma cells and in activated human B cells

Alternate splicing of exons of the CD45 molecule generates multiple isoforms differing in their molecular weights (MWs). In B-lymphocytes the CD45RA isoform was previously shown to be expressed on glycoproteins with MWs of 220 and 205 kDa, while the CD45RO isoform was expressed on glycoproteins with MW of 180 kDa. The present study demonstrated that B cell lymphomas and activated B-cells contain CD45 molecules with a MW of 185 kDa that express the CD45RA and CD45RC specificities but neither the CD45RB nor the CD45RO specificities. 185 kDa CD45RA+ molecules were detected in B cell lymphoma B lines, in Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines, and in tonsillar B cells, but not in normal, unstimulated peripheral blood B cells. These molecules were not detected in neoplastic and normal T cells. CD45RA+ 185 kDa molecules were present in B cells from three non-Hodgkin's patients in leukemic phase were not detected in B lymphocytes of seven of nine CLL patients tested. Trypsin treatment eliminated only 220 kDa CD45RA+ molecules but not 185 kDa CD45RA+ molecules, indicating that the 185 kDa CD45RA+ molecules are not expressed on the cell surface. Pulse-chase experiments, and studies on the effects of tunicamycin, neuraminidase and O-glycosidase, indicated that the 185 kDa molecules are partially glycosylated CD45RABC molecules that constitute precursors of the 220 kDa molecules. The high concentration of 185 kDa CD45RA+ molecules in B lymphoma cells and in activated B cells seems to reflect a high turnover of CD45RA+ molecules characteristic for these cells.

Serum and mucosal immunologic responses in children following the administration of a new inactivated intranasal anti-influenza vaccine

Children are at considerable risk for influenza infection and may constitute the main vector for transmitting the virus to adults in the community. At present, the use of available vaccines in children is limited mainly because of a fear of side effects from the injection. Intranasal immunization was assessed as a painless, side effect-free method of facilitating the enrollment of children in vaccination programs. One intranasal dose of a trivalent inactive whole virus vaccine containing 20 microg of the three recommended seasonal viral strains was administered to 28 children recruited over two separate winter periods (1997/1998 and 1998/1999). No adverse effects were recorded. Serum IgG responses were determined by the hemagglutination inhibition (HI) method and nasal IgA responses by enzyme-linked immunosorbent assay (ELISA). In both study period seasons, 77.7%-94.4% of children were found to be immune. There was a 3.7 x and 4.7 x increase in geometric mean titer (GMT) for A/H3N2 strains, 1.9 x and 3.9 x for A/H1N1 strains, and a 3.2 x and 1.7 x for B strains in 1997/1998 and 1998/1999, respectively. The increase in GMT, as well as fourfold increases in titer level, was higher when calculated among the nonimmune children prior to vaccination. Of these, 50%-87.5% became immune following immunization. Local antibody response to the three viral strains was detected in 50%-55% of the immunized children. Also, 83.3%, 73.3%, and 61.1% of the vaccinees exhibited a mucosal and/or serum antibody response to the A/Beijing, A/Sydney, and B/Harbin strains, respectively. This mucosal response may forestall influenza development in its early stages, thereby contributing significantly to the reduction of influenza spread in the community.

Suppressors of cancer cell proliferation from fig (Ficus carica) resin: isolation and structure elucidation

A mixture of 6-O-acyl-beta-D-glucosyl-beta-sitosterols, the acyl moeity being primarily palmitoyl and linoleyl with minor amounts of stearyl and oleyl, has been isolated as a potent cytotoxic agent from fig (Ficuscarica) latex and soybeans. Identity was established by spectroscopic methods (NMR, MS) and confirmed by chemical synthesis. Both the natural and the synthetic compounds showed in vitro inhibitory effects on proliferation of various cancer cell lines.

Depressive symptoms, satisfaction with health care, and 2-year work outcomes in an employed population

OBJECTIVE

The relationship of depressive symptoms, satisfaction with health care, and 2-year work outcomes was examined in a national cohort of employees.

METHOD

A total of 6,239 employees of three corporations completed surveys on health and satisfaction with health care in 1993 and 1995. This study used bivariate and multivariate analyses to examine the relationships of depressive symptoms (a score below 43 on the Medical Outcomes Study Short-Form Health Survey mental component summary), satisfaction with a variety of dimensions of health care in 1993, and work outcomes (sick days and decreased effectiveness in the workplace) in 1995.

RESULTS

The odds of missed work due to health problems in 1995 were twice as high for employees with depressive symptoms in both 1993 and 1995 as for those without depressive symptoms in either year. The odds of decreased effectiveness at work in 1995 was seven times as high. Among individuals with depressive symptoms in 1993, a report of one or more problems with clinical care in 1993 predicted a 34% increase in the odds of persistent depressive symptoms and a 66% increased odds of decreased effectiveness at work in 1995. There was a weaker association between problems with plan administration and outcomes.

CONCLUSIONS

Depressive disorders in the workplace persist over time and have a major effect on work performance, most notably on "presenteeism," or reduced effectiveness in the workplace. The study's findings suggest a potentially important link between consumers' perceptions of clinical care and work outcomes in this population.

Early immunological defects in comatose patients after acute brain injury

Object. The aim of this prospective study was to evaluate the phagocytic, humoral, and cellular arms of the immune system in comatose patients shortly after severe brain injury and to compare the findings with those reported earlier in patients in a persistent vegetative state. The study was conducted in intensive care units and immunology laboratories of university-affiliated hospitals in central Israel.

Methods. The study group consisted of 14 men aged 16 to 65 years who were comatose as a result of acute brain injury due to mechanical trauma. All were studied within 72 hours of injury. Brain damage was severe in all cases (Glasgow Coma Scale score < 8). Healthy age- and sex-matched volunteers served as simultaneous controls.

Infections arose in nine (75%) of the 12 patients in whom data were available; the cumulative mortality rate was 38% (five of 13 patients in whom outcome data were available). Every patient exhibited one or more defects in at least one arm of the immune system. Significant deficiencies were noted in neutrophil superoxide release, immunoglobulin (Ig)G, IgG1, IgM, C1q, C2, properdin, alternate C pathway, T cells, T helper cells, T suppressor cells, and natural killer cells. In an earlier series of patients examined by the authors months after the primary insult, these impairments were absent in most of the patients in the vegetative state.

Conclusions. Significant deficiencies of the immune system, particularly the cellular arm, are precipitated by severe brain injury within 72 hours of the event. These impairments probably play a role in the high rate of complicating infections and multiple organ failure. Together with earlier findings, the results of this study indicate that if brain-injured patients survive these hazards, their immune system will eventually recover.

Regulation of the expression of CD45 isoforms in the Farage human B cell lymphoma line and its 10.6.1 subline

Different B-cell neoplasias vary in the expression of CD45 isoforms. In the present study two sublines of a human B cell lymphoma- the original Farage line (Farage OL) and the Farage 10.6.1 subline were used to analyze the regulation of the expression of CD45 cell surface determinants. Cells of the Farage OL line constitutively expressed both CD45RO and CD45RA determinants on their cell surface. In contrast, the majority of the cells of the Farage 10.6.1 subline expressed CD45RA, and only few cells were CD45RO+. The low molecular spliced CD45 mRNA, characteristic for CD45RO was found in Farage OL cells, but was almost undetectable in Farage 10.6.1 cells. Following exposure to interleukin-4 (IL-4) a large proportion of the Farage 10.6.1 cells expressed CD45RO while in Farage OL cells the proportion of CD45RO+ was slightly reduced. The low molecular, spliced mRNA characteristic for CD45RO, was increased in Farage 10.6.1 cells following IL4 stimulation, but was slightly reduced in Farage OL cells. The molecular weight of CD45RA molecules produced by Farage cells varied from 185 kDa to 220 kDa while that of CD45RO molecules was 175 kDa. Preliminary attempts were made to determine a possible correlation between the expression of CD45RO and apoptosis in Farage cells. In both the Farage OL and Farage 10.6.1 cells the proportion of Bcl-2+ cells was lower among CD45RO+ cells than among CD45RO- cells. The present study indicates that IL4 has different effects on the alternative splicing of CD45 mRNA in two closely related B cell lymphoma lines. Thus, factors produced by the B lymphoma cells themselves may endow the cells with different patterns of responsiveness to a single stimulatory agent.

High prevalence of complement C7 deficiency among healthy blood donors of Moroccan Jewish ancestry

The incidence of the specific component deficiencies in various ethnic groups is not known, although there appears to be an ethnic predilection for C6 and C8alpha-gamma deficiencies in blacks, whereas C7 and C8beta deficiencies are predominantly noted in Caucasians. Infectious diseases, particularly recurrent meningococcal infections, are observed more commonly with late component deficiencies. In the current study, we have simplified the PCR technique by using site-directed mutagenesis and designer primers in a cohort of Israeli Moroccan Jewish blood donors to ascertain allele frequency in this ethnic group, which, based on earlier studies, was considered to be at risk for C7 deficiency. The total mutant allele frequency in this ethnic cohort was 1.1% of a total of 365 healthy Israeli Moroccan Jews, including one homozygote. The identification of mutant alleles was efficient and inexpensive, and hence a large cohort was studied. The finding of complement deficiency identifies individuals at risk for Neisserial infections, which are known to be potentially life-threatening. Conversely, when a patient of Moroccan ancestry is diagnosed with a Neisserial infection, it is important to determine the complement status.

The social roles of Medicare: assessing Medicare's collateral benefits

The Medicare program incorporates a number of functions that go beyond providing health insurance to its beneficiaries. These activities, which we refer to as "collateral" functions, may have important health consequences but are also an increasing source of controversy. In this essay we develop a conceptual framework for categorizing these involvements, introduce some additional options that might complement Medicare's current collateral functions, assess the reaction of policy elites and Medicare's current beneficiaries to these alternatives, and evaluate the role that collateral activities play for Medicare's core mission. A case can be made for expanding some collateral involvements, but only if the Health Care Financing Administration has the strategic direction and administrative capacity to effectively implement these activities.

3-m-bromoacetylamino benzoic acid ethyl ester: a new cancericidal agent that activates the apoptotic pathway through caspase-9

The mechanism underlying the cancericidal activity of 3-m-bromoacetylamino benzoic acid ethyl ester (3-BAABE) was investigated. 3-BAABE exerted a strong cancericidal effect on human leukemia and lymphoma cells (IC(50) < 0.2 microgram/mL) and on cell lines of prostate, colon, ductal, and kidney cancer (IC(50) 0.8 to 0.88 microgram/mL). Multiple drug resistance (MDR) had no effect on the susceptibility of human lymphoma cells to 3-BAABE, since Daudi/MDR(20) and wild-type Daudi cells had a similar susceptibility to the cytotoxic effect of 3-BAABE. The cancericidal effect of 3-BAABE, which was not associated with changes in the cell cycle, was mediated by apoptosis. Thus, cells exposed to 3-BAABE displayed the DNA fragmentation ladder characteristic for apoptosis, associated with a marked increase of the activity of apoptosis effector caspases-3 and -6, which was followed by proteolytic cleavage of DNA fragmentation factor (DFF) and poly(ADP-ribose) polymerase (PARP). Exposure of tumor cells to 3-BAABE increased the activity of apical caspase-9, but had no effect on caspase-8. Complete inhibition of 3-BAABE-induced apoptosis was exerted by LEHD-FMK, a caspase-9 inhibitor. DEVD-FMK, a caspase-3 inhibitor, and VEID-FMK, a caspase-6 inhibitor, partially inhibited 3-BAABE-induced apoptosis, whereas exposure to IETD-FMK, a caspase-8 inhibitor, had no effect. The fragmentation and elevated activity of caspase-9 in 3-BAABE-treated cells and the fact that only an inhibitor of caspase-9 abrogated 3-BAABE-induced apoptosis indicate that 3-BAABE is a distinctive compound that elicits apoptosis through a pathway that is limited specifically to activation of apical caspase-9.

Some distinctive features of the impact of managed care on psychiatry

Past research suggests that the spread of managed care is affecting the treatment of mental and physical illnesses differently. This article develops six hypotheses that could explain the differential effects of managed behavioral health care, based on characteristics of mental disorders, professional norms of treatment, and the broader societal consequences of untreated mental illness. Using data from the 1998 Socioeconomic Monitoring System fielded by the American Medical Association, we tested these hypotheses by comparing the experiences of psychiatrists under managed care with those of primary care providers and medical specialists. We found the following: (1) psychiatrists face substantially more aggressive external review than do primary care providers and are less successful in overturning denials; (2) psychiatrists feel significantly more at risk for disaffiliation from health plans; (3) psychiatrists report facing review protocols that are more confusing than those for primary care physicians, but psychiatrists' staff spend less time on external review; (4) psychiatrists are more likely than other physicians to report that their patients have difficulty making informed choices about managed care; and (5) psychiatrists evidence greater time commitment to advocacy on behalf of their patients with respect to managed care.

Rare Jatropha multifida intoxication in two children

Two children were admitted to the Emergency Department (ED) after ingesting a large amount of fruit of a plant identified as Jatropha multifida. They were mildly obtunded, had intractable vomiting, and seemed dehydrated. Intravenous fluid replacement and urine alkalinization were initiated. After stabilization, their 5-day hospital stays were uneventful except for a subclinical rise of liver enzymes. Jatropha species contain the toxalbumin ricin, which causes severe vomiting and diarrhea, dehydration, shock, and renal and hepatic impairment. Ricin also has cardiotoxic and hemolytic effects and several deaths have been documented. Children are attracted by the shape and the color of the Jatropha fruits. Mortality can be prevented by immediate fluid and electrolyte replacement.

B-lymphocytes in CLL and NHL differ in the mRNA splicing pattern of the CD45 molecule

In the present study the cell surface expression of CD45 isoforms on normal and neoplastic human B cells was correlated with splice products of the CD45 mRNA, using RT-PCR technology. In non-Hodgkin's lymphoma cells in the leukemic phase (NHL) the majority of the cells expressed a high level of CD45RA, while in CLL most of the cells expressed a low level. In the Raji and Daudi Burkitt B-cell lymphoma lines the main CD45 mRNA product was the largest, unspliced, full-length isoform (456) and the 56 splice product. Similar results were obtained with B-cell lymphoma cells isolated from the peripheral blood of patients with NHL in the leukemic phase. In EBV-transformed B-cell lines, the 456 and the 56 isoform of CD45 mRNA were predominant, but in addition a low level of the 5- and 0-exon splice products was detected. A strikingly different pattern was obtained with B-CLL cells. In CLL the level of the 456 and the 56 isoforms was low, while that of the 5- and 0-exon splice products was increased. Thus, in contrast to the heterogeneity in the expression of CD45RO in B-CLL, the majority of the cells contained the CD45 mRNA splice product coding for CD45RO. Analysis of splice products of the CD45 mRNA may serve as an additional tool to differentiate CLL from the leukemic phase of NHL.

Local and systemic immune response in community-dwelling elderly after intranasal or intramuscular immunization with inactivated influenza vaccine

Intramuscular (IM) influenza vaccines are about 50% effective in preventing clinical illness among the elderly and their effectiveness in eliciting mucosal response may be even lower. The aim of the present study was to evaluate the immunological effect of a novel inactivated intranasal (IN) trivalent whole influenza virus vaccine among community-dwelling elderly. Sixty-one subjects were vaccinated with two doses of an IN vaccine and a control group of 31 subjects was vaccinated with a commercial IM vaccine. Viral strains in the 1997/8 vaccine used were A/Nanchang/933/95(H3N2), A/Johannesburg/82/96(H1N1) and B/Harbin/7/94. Serum IgG and nasal IgA were determined by HI and ELISA, respectively. Only a few minor local adverse events were reported after vaccination. Seroconversion for the three antigens tested was higher after IM vaccination, although not statistically significant. Local antibody response to the three antigens tested was detected in 50-53% and 19-26% of IN and IM immunized subjects, respectively. The IN vaccine tested was significantly more effective than the IM vaccine in inducing mucosal IgA response. This may prevent influenza at its early stages and thus contribute to the reduction of complications in the elderly.

Local SIgA response following administration of a novel intranasal inactivated influenza virus vaccine in community residing elderly

Community-residing elderly were immunized twice intranasally three weeks apart with a new inactivated whole influenza vaccine. A control group was immunized intramuscularly with conventional influenza vaccine. Local antibody response was detected in about 50% of intranasally immunized subjects compared to about 20% of intramuscularly immunized subjects, to the three viral strains. Increasing the incidence of elevated IgA response may prevent influenza at its early stages thus reducing complications in the elderly.

Natural killer (NK) and T cell-associated surface marker expression following allogeneic and autologous bone marrow transplantation (BMT)

Natural killer (NK) and T cell development was studied after allogeneic and autologous BMT. We determined the phenotypic expression and lytic ability of these subpopulations after BMT. Following T cell-depleted (TCD) BMT, the number of CD16+ and CD56+ cells peaked at 39 and 46 days, respectively, and constituted the majority of peripheral blood lymphocytes (PBL). Coexpression of CD3 and CD16 was <10% up to 14.5 weeks after transplant. Following allogeneic non-T cell-depleted (NTCD) BMT, the number of CD16+ and CD56+ cells peaked at 6 weeks. CD3 expression was normal (70%-80%), % CD8+ cells was high (40%), and % CD4+ cells was low (20%). Following autologous BMT (ABMT), % CD3+ T cells was 80%, of which 70% expressed the CD8 marker. In contrast, CD4 expression was low (20%). CD16+ cells appeared 2.5-3 weeks after ABMT but with low frequency (20%), at which point 20%-30% of the CD3+ cells coexpressed CD16. A positive correlation was found between CD16 expression and cytotoxic capability. In conclusion, a marked difference was observed in NK and T cell-associated markers following TCD BMT, NTCD BMT, and ABMT. Following NTCD or ABMT, but not TCD BMT, a high percentage of cells co-express CD16 and CD3, which may indicate the possibility of a common NK and T cell progenitor.

Chronic illness and plan satisfaction under managed care

This DataWatch uses data from the 1993 Employee Health Care Value Survey (EHCVS) to compare the experiences of respondents with and without chronic illnesses under managed care. After controlling for potential confounders, we found that chronic illness was associated with increased odds of dissatisfaction in both independent practice association plans and prepaid group practices, but not under fee-for-service coverage. Chronic illness appeared to exacerbate difficulties and to attenuate the benefits experienced by healthy persons under managed care. We conclude that persons with chronic illnesses may be at particular risk under managed care; their experiences may warrant particular attention when health plan performance is being monitored.

Phagocytic killing and antibody response during the first year after tetravalent meningococcal vaccine in complement-deficient and in normal individuals

Seven individuals with late complement component (LCC) deficiency and seven control subjects were vaccinated with tetravalent meningococcal vaccine. The response to vaccination was evaluated by measuring the antibody titer and the phagocyte killing of the bacteria, before, 5-7 weeks, and 12-14 months after vaccination. Prior to vaccination, no phagocytic killing and a low titer of antibody was found in the LCC-deficient group and a low killing (mean of 40-58%, according to the serogroup) in normal controls. The phagocytic killing increased significantly 5-7 weeks after vaccination. However, while in normal controls the phagocytic killing was close to 100% after 5-7 weeks and decreased only slightly during the first year, the mean killing of the various meningococcal subgroups in LCC-deficient individuals was 70-89% and dropped to only 53-71% one year after vaccination. Six weeks after vaccination the mean antimeningococcal antibody titer increased similarly in the sera of LCC-deficient patients and controls. One year after vaccination the controls maintained the high concentration, while the LCC-deficient patients had tendency toward a decrease. In addition, the interpersonal variability of the antibody concentration, both in LCC-deficient individuals and in normal controls, was much higher than the phagocytic killing, with only a very mild increase in some individuals. Thus, it is possible that in spite of adequate increase of antimeningococcal antibody titer after vaccination of LCC-deficient individuals their immunity against the bacteria may not be optimal. Our data show also that phagocytic killing of meningococci is probably a more consistent assay than antibody titer levels for antimeningococcal immunity, especially in LCC-deficient patients.

Disclosure of HIV status to medical providers: differences by gender, "race," and immune function

OBJECTIVE

The authors used data from a larger study to explore differences by gender, self-reported racial identification, and immune function in disclosure of HIV-positive serostatus to medical providers (dentists, family doctors, and emergency room [ER] and obstetrics-gynecology [ob/gyn] providers).

METHOD

The authors analyzed interview responses from a convenience sample of African American and white men and women receiving HIV medical care at urban hospitals and clinics in St. Louis. Missouri.

RESULTS

Of 179 respondents using at least one of three types of providers, 124 (69%) disclosed their HIV status to all applicable types of providers, 39 (22%) disclosed to only one or two types of providers, and 16 (9%) did not disclose to any of these types of providers. "Race" and CD4 count, but not gender, were independently associated with disclosure to dentists, family doctors, and ER providers in multivariate logistic regression analyses.

CONCLUSIONS

Differences in disclosure rates, especially among patients who may be asymptomatic, suggest a need for public health education of both medical providers and patients with HIV.

Monocytes confer CD14 antigenicity on activated lymphocytes

In the present study, exposure of human peripheral blood mononuclear cells (PBMC) to phorbol 12-myristate 13-acetate (PMA) was found to elicit the expression of CD14 on lymphocytes. Less than 3% of the lymphocytes present among freshly isolated PBMC were stained with 63D3 anti-CD14 monoclonal antibody (mAb). Within two days of exposure of PBMC to PMA, up to 30% of the lymphocytes reacted with the 63D3 anti-CD14 mAb, though not with the LeuM3 and My4 anti-CD14 mAbs. The appearance of CD14 on lymphocytes was also elicited by exposure of PBMC to phytohemagglutinin (PHA), concanavalin A (Con A), or agarose-bound phytohemagglutinin but not by exposure to lipopolysaccharide, interferon-alpha, or interleukin-2. Purified lymphocyte preparations did not acquire CD14 following stimulation with PMA. Monocytes lost their reactivity with CD14 mAbs (63D3, LeuM3, and My4) within a few hours after exposure to PMA. The level of soluble CD14 was higher in supernatant fluids of cultures of untreated PBMC than of PMA-stimulated PBMC. The addition of PMA to cultures of T cells and monocytes separated by Millipore filters lead to the expression of CD14 on the lymphocytes. The present study indicates that activation of lymphocytes in the presence of monocytes leads to the appearance of CD14 on lymphocytes, and raises the possibility that the expression of CD14 on lymphocytes may result from the transfer of CD14 molecules from monocytes to lymphocytes.

Somatic mutations and intraclonal variations in the rearranged Vkappa genes of B-non-Hodgkin's lymphoma cell lines

Three established Burkitt's lymphoma (BL) cell lines (Daudi, Raji and DG-75) and three B-non-Hodgkin's lymphoma (B-NHL) of other types (Pfeiffer, Farage and Toledo) were analyzed with respect to the presence of somatic point mutations in their rearranged immunoglobulin Vkappa genes. Two of the Vkappa sequences of BL and two of those of the B-NHL were heavily mutated (up to 11%), when compared with their closest germline variable region counterparts ("clonal mutations"). Only one of the six cell lines contained an unmutated germline Vkappa sequence. The clonal mutations have features characteristic of the mutation machinery operating in the course of the T-dependent immune response, such as a preference of mutations in purine bases, more transitions than transversions and targeting to CDR and to known "hotspot" motifs. Sequence variations among different Vkappa PCR clones isolated from each of the cell lines ("intraclonal mutations") showed that the Vkappa of Toledo exhibited about 5-fold higher mutation frequency (MF) than the background level of Taq polymerase error (approximately 0.12% mut/bp). Similarly, the MF of Vkappa of two of the BL cell lines was 3-4-fold higher than the Taq polymerase misincorporation rate. In contrast, the mutation frequencies of the Vkappa of DG-75, Farage and Pfeiffer did not significantly exceed the level of Taq polymerase error. Our combined results show that 5 out of the 6 B-cell lines studied originated from B-cells that have already somatically mutated in vivo their rearranged Vkappa genes. Moreover, two of the Burkitt's and one of the B-NHL cell lines exhibit intraclonal variation indicating that the process of somatic hypermutation continued following the neoplastic event, either in vivo or in culture. These results are in accord with the presumed origin of the majority of the BL and some types of the B-NHL, from centrocytes or centroblasts of the germinal centers in which the process of somatic hypermutation is taking place.

Detection of minimal residual disease (MRD) after bone marrow transplantation (BMT) by multi-parameter flow cytometry (MPFC)

Multi-parameter flow cytometry (MPFC) was used to detect minimal residual disease (MRD) following bone marrow transplantation (BMT) in 21 patients. Bone marrow (BM)was analyzed pre-transplant and 3-4 months post-BMT while the patients were in clinical and morphological remission. MRD was detected by identifying cells with aberrant antigen expression and/or leukemia-associated phenotype (LAP) using MPFC. Prior to BMT, 8 out of 21 patients exhibited normal antigen expression based on normal BM samples while 13 BM aspirates had abnormal MPFC. Pre-BMT MPFC was abnormal in all 10 patients who were not in complete remission (CR) (>5% blasts in BM) as well as 3 patients acute lymphoblastic leukemia (ALL) who were in CR. In BM from ALL patients, an abnormal uniform B cell population was observed however antigen expression patterns varied greatly between patients. BM from acute myeloblastic leukemia (AML) patients showed an abnormal distribution of CD34+ cells. In addition, a correlation was observed between pre-BMT cytogenetics and MPFC. Only 2 out of 8 (25%) patients with normal MPFC pre-autologous bone marrow transplantation (ABMT) relapsed (AML), while 6 out of 13 (46%) patients with abnormal pre-BMT MPFC relapsed including 2 out of 3 patients who were transplanted in clinical CR. Pre-BMT MPFC may thus be an effective tool for detection of MRD by detection of a pre-transplant MPFC abnormality.

Time domain dielectric spectroscopy study of human cells. II. Normal and malignant white blood cells

The dielectric properties of human lymphocyte suspensions were studied by time domain dielectric spectroscopy (TDDS). Nine populations of malignant and normal lymphocytes were investigated. Analysis of the dielectric parameters of cell structural parts were performed in the framework of Maxwell-Wagner mixture formula and the double-shell model of cell. The specific capacitance of the cell membranes was estimated by the Hanai-Asami-Koisumi formula. It was shown that the dielectric permittivity, capacitance and conductivity values of cell membranes are higher for normal lymphocytes than for the malignant ones. The difference of the same parameters for normal B- and T-cells is also discussed.

No exit? The effect of health status on dissatisfaction and disenrollment from health plans

OBJECTIVE

To examine the implications of serious and chronic health problems on the willingness of enrollees to switch health plans if they are dissatisfied with their current arrangements.

DATA SOURCE

A large (20,283 respondents) survey of employees of three national corporations committed to the model of managed competition, with substantial enrollment in four types of health plans: fee-for-service, prepaid group practice, independent practice associations, and point-of-service plans.

STUDY DESIGN

A set of logistic regression models are estimated to determine the probability of disenrollment, if dissatisfied, controlling for the influence on satisfaction and disenrollment of age, race, education, family income and size, gender, marital status, mental health status, pregnancy, duration of employment and enrollment in the plan, number of alternative plans, and HMO penetration in the local market. Separate coefficients are estimated for enrollees with and without significant physical health problems. Additional models are estimated to test for the influence of selection effects as well as alternative measures of dissatisfaction and health problems.

DATA COLLECTION

Data were collected through a mailed survey with a response rate of 63.5 percent; comparisons to a subsample administered by telephone showed few differences.

PRINCIPAL FINDINGS

In group/staff model HMOs and point-of-service plans, only 12-17 percent of the chronically ill enrollees who were so dissatisfied when surveyed that they intended to disenroll actually left their plan in the next open enrollment period. This compared to 25-29 percent of the healthy enrollees in these same plans, who reported this level of dissatisfaction and 58-63 percent of the enrollees under fee-for-service insurance.

CONCLUSIONS

Switching plans appears to be significantly limited for enrollees with serious health problems, the very enrollees who will be best informed about the ability of their health plan to provide adequate medical care. These effects are most pronounced in plans that have exclusive contracts with providers. We conclude that disenrollment provides only weak safeguards on quality for the sickest enrollees and that reported levels of dissatisfaction and disenrollment represent inaccurate signals of plan performance.

Depressive symptoms and plan switching under managed care

OBJECTIVE

A central assumption underlying managed care is that plan switching is a viable option for enrollees when they are dissatisfied. The authors used a national employee survey to test the hypothesis that this mechanism is less effective for enrollees with high levels of depressive symptoms than for the remainder of the population.

METHOD

The study used data from the Employee Health Care Value Survey, a 1993 survey of 20,283 employees of three major corporations. The authors used the Medical Outcomes Study 36-Item Short-Form Health Survey to identify individuals with the highest decile of depressive and physical symptoms. They examined the relationship between symptoms and dissatisfaction and, for dissatisfied individuals, how symptoms predicted plan switching. Multivariate models were used to control for potential demographic, health, and health coverage confounders.

RESULTS

Depressive and physical symptoms were both associated with dissatisfaction with care. Unlike physical symptoms, depressive symptoms were associated with a significantly lower likelihood of actually disenrolling among people who were dissatisfied or who intended to disenroll. This effect was most pronounced for satisfaction with administrative aspects of care (e.g., gatekeeping, utilization review).

CONCLUSIONS

People with high levels of depressive symptoms appeared to be less willing or able to act on their dissatisfaction by switching plans. In particular, they were willing to tolerate higher rates of dissatisfaction with the administrative aspects of their health coverage without disenrolling. Plan switching is an essential mechanism underpinning a health care system predicated on competition; it may be less effective for people with depressive disorders.

Hypocomplementemia in multiple myeloma

We report the results of a prospective study of the complement system in a cohort of 22 multiple myeloma patients: 11 women and 11 men, median age 66 years. There were 10 IgG, 8 IgA, 2 IgM and 2 light chain myeloma patients. Seven were in stage 1, 3 in stage 2 and 12 in stage 3. The serum complement component levels of the three pathways were measured in all patients and compared to normal values of 29 healthy controls. We found a depleted common pathway in 21 patients, and deficient alternative and terminal pathways in 6 patients. There was no difference in the complement profile of myeloma patients in the advanced or early stages of the disease. IgG and IgA myeloma patients had a similar complement profile. Nine patients, 7 with advanced disease, developed 17 infectious episodes. Most of these patients had a deficient classical pathway, but normal alternative and terminal pathways. This profile was not different from the complement system observed in patients without infectious complications. Activation of the three pathways of the complement system was evaluated in all 22 patients. The classical and alternative pathways were activated in most patients in early and late stages, but the terminal pathway (C5-C9) was more frequently activated in the later stages (7 of 12 patients) that in the earlier stages (1 of 10). We conclude that the complement system is deficient in multiple myeloma, most probably because of activation of the system, although no correlation could be demonstrated between the complement system and the clinical manifestations of the disease.

Lymphocyte subset profile of young healthy children residing in a rural area: possible role of recurrent gastrointestinal infections

BACKGROUND

Lymphocyte subsets in healthy children are currently characterized by age-related standards. Because antigenic stimuli play a role in maturation of the immune system after birth, there is a question of whether cellular immune development differs in infants whose living conditions entail extensive antigenic exposure and infants growing up in a more protected environment.

METHODS

Peripheral blood lymphocyte subsets were studied in two populations of children of similar age and nutritional status; children belonging to a rural population residing in proximity with farm animals and children from an economically privileged urban population. In each population, children studied included a group with an acute diarrheal episode and a healthy control group.

RESULTS

Among rural population children, 65% had experienced at least one episode of gastroenteritis within the previous 3-month-period, compared with less than 10% of urban population children. In the rural population group 15% had experienced two or more episodes of gastroenteritis. The proportion of helper T cells was similar in rural population and urban population children. Among helper T cells, the proportion of CD29+ "memory" cells of the total CD4+ helper T cells was more than two times higher than those in rural population children. The proportion of CD8 cells was higher in rural population children than in urban population children, and the proportion of natural killer cells, CD56+ and CD57+, was two to three times higher in rural population children. Within each population, peripheral blood lymphocyte subsets did not differ between the healthy control group and those with acute diarrhea.

CONCLUSIONS

In young children exposure to environmental pathogens and specifically to gastrointestinal antigenic stimuli is a major factor affecting development of the cellular immune response. Young children who have experienced enhanced infectious exposure have a peripheral blood lymphocyte profile similar to that of adults.

Analysis of myeloid and lymphoid markers on the surface and in the cytoplasm of mononuclear bone marrow cells in patients with myelodysplastic syndrome

Mononuclear cells of the bone marrow (BM) of patients in various subgroups of the myelodysplastic syndrome (MDS) were studied by flow cytometry for the expression of myeloid and lymphoid markers both on the surface and in the cytoplasm. A significantly higher percentage of the BM cells of MDS patients reacted with monoclonal antibodies (mAbs) to myeloid antigens (CD13, CD15 and CD33) by cytoplasmic staining as compared with cell surface staining. The percentage of BM cells expressing CD34 was markedly elevated in patients with RAEB-T. A distinct finding in MDS patients was the expression of myeloid antigens on mononuclear BM cells. The proportion of individuals whose mononuclear BM cells were positive for surface reactivity with anti-CD13 and anti-CD33 mAbs was highest among RAEB-T patients while none of the patients with RA expressed these surface antigens. Cytoplasmic staining significantly increased the percentage of CD13+ and CD33+ BM cells among RAEB and RAEB-T patients. The proportion of individuals whose BM cells possessed myeloid antigens was increased by cytoplasmic staining in all subgroups of MDS. The BM of a considerable proportion of RAEB-T and RAEB patients showed cells which coexpressed the CD7 and CD3 lymphoid markers along with the CD13 and CD33 myeloid antigens. The present study indicates the importance of comparative surface and cytoplasmic immunophenotyping with CD13 and CD33 mAbs for the diagnosis of subgroups of MDS. The coexpression of CD3 and CD7 with markers of the myeloid lineage may reflect derangement of the differentiation of pluripotent stem cells characteristic for MDS.

Risk, motives, and styles of utilization review: a cross-condition comparison

In the United States various forms of managed care have been introduced to control the use of expensive medical services. One of the most prominent involves utilization review of hospital admissions. While reviewing the appropriateness of inpatient treatment is appealing in principle, its application is made difficult by clinical uncertainty. Managed care plans develop and implement review criteria often without the guidance of clear clinical norms of treatment. Under these conditions, we suggest that utilization review organizations (UROs) can be expected to develop "styles" of review that respond to clinical uncertainty, influenced by their experience, professional orientation, and financial incentives. Two review styles are explored in this paper: standardization, where the URO reduces the variance in clinical practices by eliminating those practices that deviate from professional norms and stringency, whereby the URO shifts the distribution of clinical practice as it tries to change the professional norms of practice. Data from a 1992-1993 national survey of utilization review organizations are used to test whether UROs have review styles that systematically respond to organizational attributes, economic pressures, and clinical uncertainty associated with three medical conditions: cardiac catheterization, low back pain, and adolescent depression. UROs were found to adopt more stringent review strategies for conditions with weaker norms of appropriate treatment. Financial incentives and organizational experience are positively related to greater stringency. Standardization responds to professional orientation and organizational experience. Variation in the review styles of UROs has implications for the resulting distribution of clinical practices as well as the equity of access to medical care.

Hypocomplementemic autosomal recessive hemolytic uremic syndrome with decreased factor H

We describe the clinical course, complement components, and pathological findings of 10 infants with autosomal recessive hemolytic uremic syndrome (HUS). All patients were members of one extended highly inbred Bedouin kindred. The median age of presentation was 2 weeks (range 1-20 weeks). Eight patients died, 2 patients are alive, on dialysis. Renal biopsies revealed thrombotic microangiopathy with a predominant early arteriolar involvement and subsequent development of ischemic glomerular changes. Immunofluorescence was positive for C3 in glomeruli. All patients had low complement components levels during and between relapses, and in some this was evident soon after birth and prior to the onset of symptoms. This deficiency could not be normalized by repeated plasma transfusions. Biosynthetic labelling of patients' fibroblasts demonstrated normal rates of C3 protein synthesis. Serum factor H levels were greatly decreased or absent in 4 patients tested and moderately decreased in 15 of 23 healthy unaffected siblings and patients. This defect may cause complement activation and consumption, possibly at the endothelial cell level.