Mortality from chronic nonspecific lung disease reported in the United States and in England and Wales during the period 1968 to 1976 was studied to determine if excessive deaths from this condition were associated with epidemics of influenza. In both countries, peaks of excess mortality of this type did indeed occur during such epidemics; however, these excesses were considerably more marked in the British data where the estimated number of such deaths over the 8-yr period was 15,800 compared with 6,000 for the United States. There was a decreasing secular trend in age-specific death rates for chronic nonspecific lung disease among British males of all ages, whereas only middle-aged males showed such a trend in the United States; older American males were subject to a substantially increasing trend. The respective trends in such mortality observed among males in the 2 countries were also seen among females but were smaller in magnitude.

The tumorigenicity of adenovirus (Ad) 12-transformed mouse cells was evaluated by analyzing the relationship of tumor cell dose to tumor incidence and tumor latency. The tumor producing dose 50% endpoint values used to define these relationships remained stable during 52 weeks of serial passage in tissue culture and were not determined by low frequency events within the cell population. The data from these analyses suggest that the phenotype of Ad12-transformed mouse cells is influenced by two set of traits--those traits that determine the threshold number of cells required for tumor formation and those that extend the cell dose-dependent tumor latency period. Both traits are established independently of cell immortalization, and both can be influenced by the immunological status of tumor-challenged animals. These observations were verified by using mouse cells transformed by Ad5 and SV40. The biological and molecular processes that contribute to these traits remain to be determined. The approach developed by this analysis provides a reliable, quantitative means of evaluating endogenous traits that determine transformed cell tumorigenicity. This method can also be used to test the effects of tumor cell manipulations or changes in host response that could alter expression or detection of these neoplastic cell traits.

The aims of this study were to determine whether long-term oral administration of the opiate antagonist nalmefene is associated with any beneficial effects in patients with pruritus secondary to cholestatic liver disease and to assess the safety of long-term administration of this drug to these patients. Fourteen patients with unrelieved chronic pruritus of cholestasis were studied. Scratching activity, independent of limb movements, was recorded continuously for 24-hour periods before and during treatment with an initial ameliorating dose of nalmefene. Simultaneously, during these periods, visual analogue scores (VASs) of pruritus were recorded every 4 hours while patients were awake. The dose of nalmefene, which initially was 2 mg orally twice daily, was increased during the study, usually until a satisfactory clinical response was achieved. Five patients experienced a transient opioid withdrawal-like reaction that did not preclude continuing with nalmefene therapy. Serum biochemical indices of cholestasis did not change appreciably during treatment. Thirteen patients reported amelioration of the perception of pruritus on nalmefene. In 5 patients, exacerbations of pruritus occurred approximately 4 weeks after an initial ameliorating dose had been reached; these exacerbations were managed by increasing the dose. Baseline mean values for VAS and scratching activity were higher than corresponding means during nalmefene therapy in 13 (P = .002) and 12 (P = .013) patients, respectively. Possible tolerance to nalmefene occurred in 3 patients. Three patients experienced marked exacerbation of pruritus after nalmefene therapy was suddenly discontinued. Blood levels of nalmefene were consistent with normal pharmacokinetics of the drug. These results suggest that nalmefene may have a favorable risk-to-benefit ratio when it is administered orally long-term to patients with the pruritus of cholestasis.

To enhance and steer immune responses to synthetic peptide vaccines toward selected functional types and to understand the cooperative action of cytokines in fine-tuning the immune response, we attempted to influence the in vivo cytokine environment by delivering cytokines directly to the microenvironment in which the immune response is initiated. Here we study the effects of IL-2, IL-4, IL-7, IL-1beta, IL-12, IFN-gamma, TNF-alpha, and granulocyte-macrophage CSF (GM-CSF) incorporated with peptide in adjuvant on a variety of responses elicited: CTL, T cell proliferation, cytokine production and message, and Ab isotype. We show GM-CSF to be the single most effective cytokine for enhancing both cellular and humoral immunity to two previously characterized HIV-1 MN vaccine constructs. Novel synergies were also detected. GM-CSF synergized with IL-12 for CTL induction in BALB/c mice concomitant with suppression of Th2 cytokines IL-4 and IL-10. TNF-alpha also synergized with IL-12, but by a different mechanism, inducing IFN-gamma production in BALB/c mice and thus shifting the response to a Th1 phenotype. The results presented here suggest that in addition to IL-2, optimum induction of CD8+ CTL in vivo requires a combination of cytokines, including GM-CSF (probably acting to enhance Ag presentation and CD4+ cell help) and IL-12 (steering the Th response toward Th1 cytokines).

We examined the effects of a human milk diet on rats with chemical colitis induced with a 4% acetic acid enema. Colonic myeloperoxidase activity was used as a surrogate marker for neutrophil infiltration. Control rats fed rat chow had little colonic myeloperoxidase activity; geometric mean, 0.27 U/g of tissue. Rats with colitis fed rat chow had significantly increased colonic myeloperoxidase activity (geometric mean, 6.76 U/g, p < 0.01 versus no colitis), as did rats with colitis fed infant formula or Pedialyte (geometric mean, 6.92 and 8.13 U/g, respectively, both p < 0.01 versus no colitis). Animals with colitis fed human milk had significantly lower colonic myeloperoxidase activity (geometric mean, 2.34 U/g) than did animals with colitis fed either chow or infant formula (p < 0.001). Similar effects were seen in rats with colitis fed infant formula supplemented with recombinant human IL-1 receptor antagonist (geometric mean, 1.95 U/g). These data show that orally administered human milk has an antiinflammatory effect on chemically induced colitis in rats, which may be mediated in part by IL-1 receptor antagonist contained in human milk.

'Sawtoothed' waves occur during rapid eye movement (REM) sleep, but their source as well as their function is not known. We studied the onset of sawtooth waves (STW) in relation to the onset of muscle tone reduction (MTR) and to REM during 20 polysomnographic recordings in 11 normal volunteers. Seventy-seven (85%) of a total of 91 REM sleep cycles were used for further analysis, because within a 1000 s interval they showed a relatively stereotyped sequence of events: a generalized body movement, followed by MTR, then the appearance of STW, and ending with the first REM. The first STW often occurred during the electrographic stage II period prior to the beginning of the REM, by which time muscle tone was either already at or close to the tone level of the REM sleep period in all subjects. The overall mean onset time of MTR was 267 s (range 89-660 s), STW was 378 s (range 169-779), and REM was 448 s (range 265-849); their differences were highly significant (F = 27.1, df 2,20, P < 0.001). Our data suggest that a predictable sequence of muscle tone reduction, then STW, and then REM, precedes the generally accepted onset of the REM sleep period, and may have implications for the redesignation of physiologic REM sleep onset.

The C-terminal 19-kDa, epidermal growth factor-like region of the merozoite surface protein 1 (MSP1) has been used as a vaccine to induce protective immunity to Plasmodium yoelii in mice and to Plasmodium falciparum in monkeys. To analyze the mechanisms and genetic regulation of this MSP1 vaccine-induced protection, we studied the immunologic correlates of protection in H-2 recombinant and congenic mouse strains on the B10 background. Multiple H-2-linked loci were found to contribute, each with a different mechanism. One locus mapped to the I-A region based on the strong protection in C57BL/10 mice compared with intermediate protection in B10.A(4R) mice and the lack of a difference between B10.AKM and B10.MBR mice. Differences in efficacy of passively transferred antisera from vaccinated C57BL/10 vs B10.A(4R) mice indicated that the protection regulated by the I-A locus was at least in part Ab dependent. Two loci mapped to the right of I-A (FE, H-2S, or H-2D) based on a correlation with the number of H-2k loci to the right of I-A in mice that were I-Ak. One effect was Ab independent and may correspond to a possible negative effect of the I-Ek locus. T cells from protected and nonprotected strains differed in their production of IFN-gamma and TNF-alpha following immunization with MSP1(19), but it was unclear how the differential patterns of cytokine expression related to the level of protection. Thus, MSP1(19) vaccine-induced protection is regulated by H-2-linked loci corresponding to two different immune mechanisms. These findings may indicate the need for more than one Ag in a vaccine to protect an HLA-diverse population.

ABSTRACT. We developed a method to study the DNA synthetic cycles of Entamoeba histolytica and Entamoeba invadens by flow cytometry (FCM) based on a preparative procedure to reduce both high levels of natural fluorescence and non‐specific adsorption of fluorochromes. We modeled G 1 , S, and G 2 phases as a series of overlapping Gaussian curves. Both E. histolytica and E. invadens displayed G 1 , S, and G 2 proportions that are consistent with eukaryotic cell populations in exponential or stationary growth phase. Exponential phase E. histolytica populations contained a hypodiploid subset with a mass of about 20% less than the diploid value which we estimate by FCM to be 24 × 10 ‐14 g DNA/cell. Exponential phase E. invadens populations contained a hypodiploid subset with a mass of about 6% less than the diploid value which we estimate by FCM to be 30 × 10 ‐14 g DNA/cell.

The age-specific seroprevalence of antibody to hepatitis A virus (HAV) and antibody to hepatitis E virus (HEV) were studied in persons in Pune, India, where both viruses are endemic. The data showed that HAV infected the majority of persons by age 3 years and virtually 100% by late childhood. In contrast, infection with HEV was rare in children and did not reach peak prevalence (33%-40%) until early adulthood. The reason for the differences in infection rates between HAV and HEV is not known. Age-specific antibody patterns in serum samples obtained 10 years apart show that neither HAV nor HEV has diminished in medical importance in this Indian community.

Rabbits can be infected with human immunodeficiency virus (HIV-1), but no disease signs similar to acquired immunodeficiency syndrome (AIDS) have been reported to date. In our attempt to develop types of HIV-1 more virulent for rabbits, an immunodeficiency characterized by CD4+ lymphocytopenia and opportunistic infection was induced by transfusion from HIV-1-infected rabbits. The original donor was infected for 27 months; initial passage resulted in infection of two rabbits. Transfusions from these two infected rabbits. Transfusions from these two infected rabbits caused immunodeficiency in 12 recipients. One rabbit died at 3 months and a second at 8 months postransfusion with lymphocyte depletion in lymphoid organs; one of these and another of the CD4+ lymphocytopenic rabbits had opportunistic infections. Lentivirus-like particles were detected in thymus and spleen from an affected rabbit. Despite appearance of AIDS-like disease signs, antibodies to HIV-1 probes were detected in rabbits receiving passaged blood. However, RNA transcripts hybridizing with HIV-1 probes were detected in organs of some rabbits, implicating the initial HIV infection in the disease. Transfusion from uninfected donors produced no signs of immunodeficiency, which suggests the involvement of an HIV-related agent. The present data do not allow definitive characterization of the agent(s) involved in the immunodeficiency. Possibilities include activation of a rabbit retrovirus or, alternatively, development of a mutated HIV-1 strain.

In a controlled, randomized trial, the authors investigated the effects of reconstituted human high-density lipoprotein (R-HDL) on survival, endotoxemia, cytokine production and pathophysiologic and metabolic events in an animal model of gram-negative septic shock. At 0.5, 8 and 16 hr after implantation of a clot infected with Escherichia coli, canines received intravenous R-HDL (n = 13), control lipid (n = 7) or human serum albumin (HSA, n = 7) divided into three doses (0.3, 0.1 and 0.1 g/kg, respectively) at an hourly rate of 0.1 g/kg. All animals were treated with antibiotics and fluids. Animals treated with R-HDL had lower levels of circulating endotoxin and tumor necrosis factor and a smaller decrease in white blood cell counts than did animals treated with lipids and HSA (all P < .05). The survival times of lipid- and HSA-treated animals were similar (P = .3) and were significantly greater than those of R-HDL-treated animals (P = .02). During the first 6 hr after clot implantation, R-HDL-treated animals had significantly greater abnormalities in liver function test findings compared with lipid- and HSA-treated animals (all P < .05). For the first 24 hr, R-HDL-treated animals had significant increases in HDL levels; however, there were no significant relationships between these levels and the constituents of HDL (apolipoprotein AI and phosphatidylcholine) or liver function abnormalities and survival times (all r < .2, P > .3). In normal animals, administration of R-HDL (in similar doses) caused transient elevation of liver enzymes; in animals given sterile clot i.p., R-HDL caused seizures.(ABSTRACT TRUNCATED AT 250 WORDS)

Invasion of erythrocytes by malaria parasites involves multiple receptor-ligand interactions. To elucidate these pathways, we made use of four parasite clones with differing specificities for invasion, erythrocytes that are mutant for either glycophorin A or B, and enzyme modification of the erythrocyte surface with neuraminidase and trypsin. Neuraminidase alone abolishes invasion of two parasite clones (Dd2, FCR3/A2); these invade after trypsin treatment alone. A third clone (7G8) is unable to invade trypsin-treated erythrocytes. The fourth clone (HB3) can invade after either neuraminidase or trypsin treatment. The receptor for invasion of trypsin-treated erythrocytes was explored in two ways: treatment of trypsin-treated normal cells with neuraminidase, and trypsin treatment of glycophorin B-deficient cells. Both treatments eliminated invasion by all clones, indicating that the trypsin-independent pathway uses sialic acid and glycophorin B. To identify parasite proteins involved in the different pathways, erythrocyte binding assays were performed with soluble parasite proteins from each clone. Based on binding assays using erythrocytes that lack glycophorin A, the parasite protein known as EBA-175 appears to bind predominantly to glycophorin A. In contrast, the glycophorin B pathway does not appear to involve EBA-175, as binding of EBA-175 was similarly reduced to trypsin-treated normal and trypsin-treated glycophorin B-deficient erythrocytes. Thus, the glycophorin B-dependent, sialic acid-dependent invasion of trypsin-treated normal erythrocytes uses a different parasite ligand, indicating two or more sialic-dependent pathways for invasion. Clone 7G8, which cannot invade trypsin-treated erythrocytes, may be missing the ligand for invasion via glycophorin B. Redundancy in the invasion process may give a selective advantage to parasites that must survive in polymorphic human populations.

Murine B lymphocyte clones have proven to be useful models to study aspects of B lymphocyte growth and development. It had been previously shown that induction of TH2.2 (B lymphoma X B lymphocyte) with LPS resulted in differentiation into IgM-secreting cells (a feature similar to other B cells lines such as BCL1), and secretion of granulocyte-macrophage-CSF. Many transformed and nontransformed lines (including TH2.2) have been shown to generate progeny heterogenous in size and secretion of product when exposed to mitogen. We extend this study to demonstrate heterogeneity in secretion of IgM, granulocyte-macrophage-CSF, IL-3, and IL-6 in LPS-induced TH2.2. Clones generated by limiting dilution were heterogenous with respect to size, type, and quantity of product secreted. Microscopic clones ranged from 10 to about 1000 cells in size and could not be grown further; the majority secreted one product (mainly IgM). These clones were very efficient secretors of IgM and probably consist mainly of terminal-secreting cells. Microscopic clones secreting cytokine were also efficient producers. Visible clones from LPS-induced cultures grew to the same size as uninduced clones and were often restricted in secretion of products. Although the majority secreted three of four products (52%), many secreted IgM only or IgM and one cytokine. Although there was a strong tendency for clones to secrete multiple products, almost every secretory phenotype could be found. Amounts of different products secreted were not correlated, suggesting an additional level of independent control of this variable. Restriction of secretion was not due to genetic variation because visible clones originally restricted in secretion almost always produced all products when expanded and retested. These findings indicate that cells of TH2.2 were heterogeneous with respect to growth and secretion in the presence of LPS and were individually programmed for differentiative responses. The programming of cells was not permanent, but subject to dynamic change.

Objective: To determine whether oral acyclovir reduces the incidence of recurrent herpes labialis in otherwise healthy patients with proven frequently recurrent disease.Design: Randomized, double-blind, placebo-controlled, crossover trial.Setting: Outpatient facility of the Clinical Center, National Institutes of Health, Bethesda, Maryland.Patients: Fifty-six otherwise healthy adults who reported frequently recurrent herpes labialis (greater-than-or-equal-to 6 episodes/y) were enrolled into the study. During a 4-month observation period, 22 patients had herpes labialis two or more times and were eligible for study treatment.Interventions: Twenty-two patients were randomized to receive either acyclovir, 400 mg twice daily, or matched placebo for 4 months. After the first treatment period, patients were given the alternate treatment for another 4 months and were then taken off study medication to observe the first post-treatment recurrence. Recurrent outbreaks were determined by examination and by viral culture.Results: Twenty patients completed blind treatment with both acyclovir and placebo. The median time to first clinically documented recurrence was 46 days for placebo courses and 118 days for acyclovir courses (P = 0.05). The mean number of recurrences per 4-month treatment period was 1.80 episodes per patient during placebo treatment and 0.85 episodes per patient during acyclovir treatment (P = 0.009). The mean number of virologically confirmed recurrences per patient was 1.40 with placebo therapy compared with 0.40 with acyclovir (P = 0.003).Conclusions: Oral acyclovir, 400 mg twice daily, is effective in suppressing herpes labialis in immunocompetent adults confirmed to have frequently recurrent infection. Treatment with acyclovir in this study resulted in a 53% reduction in the number of clinical recurrences and a 71% reduction in virus culture-positive recurrences compared with placebo therapy.

Objective.-To investigate the therapeutic efficacy and microbiological and physiological effects of a human IgM monoclonal antibody (HA-1A) directed against the lipid A component of endotoxin in a canine model of sepsis that simulates the cardiovascular abnormalities of human septic shock.Design.-Blinded, placebo-controlled 28-day trial.Interventions.-Purpose-bred beagles were implanted with an intraperitoneal clot infected with Escherichia coli O111:B4. At clot placement, animals received HA-1A (10 mg.kg-1), control human IgM antibody (10 mg.kg-1), or control human serum albumin intravenously. All animals were given antibiotic and fluid therapy.Measures.-Survival and microbiological and physiological events.Results.-Only two (15%) of 13 animals in the HA-1A group, compared with eight (57%) of 14 control animals (combined control human IgM antibody and control human serum albumin groups) (P=.05), survived 28 days. At 24 hours, the HA-1A group had lower mean arterial pressure (P=.04) and cardiac index (P=.004) and higher lactate levels (P=.05) compared with the combined-controls group. In addition, these parameters in the HA-1A group were significantly more predictive of death. The HA-1A and combined-controls groups had similar significant increases in the level of endotoxemia and bacteremia. Studies of toxic effects showed no harmful effects of control human IgM antibody in infected animals or HA-1A in non-infected animals.Conclusion.-In a canine model of E coli sepsis, HA-1 A did not alter levels of bacteremia or endotoxemia and actually decreased survival. If these data are relevant to human septic shock, HA-1A therapy should be limited until the conditions under which this monoclonal antibody has beneficial or deleterious effects are more completely defined.

1. Parameters affecting the binding of the tricyclic drugs imipramine and 3-chloroimipramine to Giardia lamblia trophozoites were studied. 2. Two to three times more chlorimipramine than imipramine was bound, consistent with a similar difference in suppressing parasite growth (Weinbach et al; 1985). 3. Kinetic analysis and the ease with which bound drugs can be washed out of the parasites indicate that noncovalent forces are involved in the drug-parasite interaction. 4. Evidence is presented that such drugs probably bind to parasite protein at common binding sites. 5. The data relate to our earlier observation that chlorimipramine is about ten times more effective than metronidazole (Crouch et al., 1986) in suppressing G. lamblia growth in vitro. Tricyclic drugs, therefore, merit serious consideration as novel therapeutic agents against giardiasis.

To test the hypothesis that opioid agonist activity contributes to the pruritus of cholestasis, a placebo-controlled single-blinded trial of naloxone, an opioid antagonist, was conducted in eight patients with primary biliary cirrhosis. After discontinuation of all conventional antipruritic medications, one or two continuous (24-hour) IV infusions of naloxone (0.2 micrograms.kg-1.min-1) and placebo solution were administered consecutively in an order that was not predetermined. Pruritus was assessed subjectively by means of four hourly recordings of a visual analogue score. In addition, objective measurements of scratching activity that were independent of gross body movements were continuously recorded using an apparatus specifically designed to measure the frequencies associated with this activity. No side effects associated with naloxone infusions were observed. Only scratching activity data obtained for the same periods of day and night during both naloxone and placebo infusions were compared. Naloxone infusions were consistently associated with a decrease in values of the scratching activity index. In addition, in 50% of the patients the infusions were associated with a decrease in visual analogue score. The mean decrease in scratching activity ranged from 29% to 96% (mean, 50%; P less than 0.001). These findings imply that increased opioid agonist activity contributes to scratching activity in cholestatic patients.