BI-RG-587 is active against zidovudine-resistant human immunodeficiency virus type 1 and synergistic with zidovudine.

A series of dipyridodiazepinones have been shown to be potent inhibitors of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. The lead compound, BI-RG-587, had a 50% inhibitory concentration of 84 nM against HIV-1 reverse transcriptase activity. This compound reduced plaque formation of HIV-1 in HeLa cells expressing the CD4 receptor by 50% at 15 nM. BI-RG-587 at comparable concentrations inhibited the production of p24 antigen following the acute infection of CEM T-lymphoblastoid cells or primary human monocyte-derived macrophages with HIV-1. No inhibitory effects against HIV-2 or against three picornaviruses were detected. Zidovudine (3'-azido-3'-deoxythymidine [AZT])-susceptible and AZT-resistant isolates of HIV-1 were equally susceptible to BI-RG-587. AZT and BI-RG-587 exhibited synergistic inhibition of HIV-1BRU at all concentrations examined.

Dementia and agitation in nursing home residents: how are they related?

The link between agitated behaviors and cognitive functioning in 408 nursing home residents was examined. Results showed that cognitively impaired residents manifested aggressive behaviors (e.g., cursing, hitting) and physically nonaggressive behaviors (e.g., pacing). The highest levels of physically nonaggressive behaviors were manifested by those residents who presented intermediate levels of impairment in their performance of activities of daily living. Cognitively intact residents exhibited verbally agitated behaviors (e.g., complaining). These findings have important implications for caregivers of agitated nursing home residents.

Medical correlates of agitation in nursing home residents.

This paper examines the relationship between agitation and medical and psychiatric diagnoses. Agitation marked by aggressive behaviors (e.g., hit, kick) was related to dementia and impairments in activities of daily living. Physically nonaggressive behaviors (e.g., pacing, disrobing inappropriately) correlated with cognitive impairment, fewer medical diagnoses, and absence of a hearing loss. Verbally agitated behaviors (e.g., constant complaints) were manifested by residents with more physical diagnoses, mental disease (other than schizophrenia and affective disorders), more reported pain, and higher cognitive functioning than the population as a whole.

Evaluation of zinc complexes on the replication of rhinovirus 2 in vitro.

The effect of zinc salts and complexes were evaluated on the replication of rhinovirus 2 in vitro. Zinc chloride inhibited the replication of rhinovirus 2 at concentrations between 3 and 12 micrograms/ml. Influenza virus was not affected. A number of zinc complexes were tested and compared to zinc chloride. The results indicated that the activity and toxicity of all zinc complexes in the rhinovirus cytopathogenic effect (CPE) assay were directly related to the amount of unbound zinc available.

A description of agitation in a nursing home.

Agitation is a significant problem for elderly persons, their families, and their caregivers. This study describes the agitated behaviors of 408 nursing home residents. Nurses who were familiar with the residents used a 7-point scale to rate how often each resident manifested 29 agitated behaviors. Each resident was rated independently by three nurses, one from each of the three nursing shifts. Results showed that agitated behaviors occurred most often during the day shift (i.e., when residents were most active), and least often during the night shift. The most frequently exhibited agitated behaviors were general restlessness, pacing, repetitious sentences, requests for attention, complaining, negativism, and cursing. Most agitated behaviors correlated significantly across shifts, suggesting that such behaviors occur and reoccur throughout the 24-hour day. Factor analysis yielded three syndromes of agitation: aggressive behavior, physically nonaggressive behavior, and verbally agitated behavior. These results provide a foundation for further studies of agitation in elderly persons.

Absenteeism of nursing staff in a nursing home.

This study investigated absenteeism among nursing staff at a long-term care facility. Four absenteeism measures were calculated from personnel records for each month of the year: no pay, sum of unscheduled, unpaid-sick and leave without pay; part-day, sum of arrived late and left early; paid-sick; and total. Independent variables included job level, part/full-time status, shift, sex, marital status, number of tax exemptions, birth year, and year of employment. Absenteeism was lowest in winter; lower for higher level staff; higher the greater the number of exemptions taken; and most importantly, lower for staff with seniority.

Suppression of in vitro granulocytopoiesis by captopril and penicillamine.

The mechanisms underlying drug-induced neutropenia are poorly characterized. We have examined the mechanism of suppression of granulocytopoiesis by captopril and penicillamine using human and canine bone marrow cells in an in vitro culture system. Addition of captopril caused no significant change in granulocyte-macrophage colony formation at concentrations up to 30 micrograms/ml. In the presence of CuSO4 (1-3 micrograms/ml), however, captopril caused significant inhibition of colony growth (p less than 0.05). Penicillamine, another agent associated with neutropenia and, like captopril, having a reactive thiol group, also inhibited colony formation in the presence of copper. Chemical congeners of captopril lacking a reactive thiol group and enalaprilic acid, an alternative angiotensin-converting enzyme (ACE) inhibitor, failed to show inhibition, suggesting that the thiol group and not ACE inhibition was responsible. Analysis of day-7 colonies (98% neutrophilic) and day-21 colonies (37% neutrophilic, 30% macrophagic, 27% eosinophilic, and 6% mixed) showed that neutrophil-containing colonies, but not nonneutrophilic colonies were inhibited by the addition of captopril plus copper. Catalase totally reversed the inhibition of colony formation caused by these agents. Direct measurement of oxygen consumption in the presence of captopril showed marked enhancement with the addition of CuSO4 and a 48% reduction in the presence of added catalase. These data indicate that drugs with a reactive thiol group can interact with copper to generate H2O2, which can be toxic to neutrophilic progenitor cells. We postulate that this may be an important mechanism for drug-associated neutropenia and a general mechanism for drug-induced marrow cell injury.

Delineation of Ia:nominal antigen complementary determinants recognized by T cells in studies of gene complementation in response to insulin.

The immune response to beef insulin in mice is controlled by genes in the IA subregion. We have previously shown that B6.C-H-2bm12 (bm12) mice, an A beta gene mutation of B6, have a selective loss of responsiveness to beef insulin, whereas other IAb controlled responses such as (TG)AL and collagen are unchanged. F1 hybrid mice between two nonresponder genotypes Ik and Ibm12 were found to be good responders to beef insulin suggesting functional complementation. In this report, we define the cellular and molecular basis of this complementation by investigating the determinants on Ia molecules and nominal antigen that are recognized by (B10.A X bm12)F1 proliferating T cells. Genetic analyses demonstrated that the Ik region was the only nonresponder genotype that complemented Ibm12, thus restoring responsiveness to beef insulin. More precisely an IAk and not an IEk gene product was found to be responsible for this complementation. Antibody blocking studies furthermore showed that the A alpha b:A beta k hybrid Ia mediated the response to beef insulin in (B10.A X bm12)F1 mice. Clonal analyses of the response to beef insulin in these F1 mice confirmed these conclusions, because the insulin-specific response in all 21 F1-T cell clones studied thus far was found to be dependent upon presentation via the A alpha b:A beta k hybrid Ia molecule. Dissection of the antigenic specificity of the F1-T cell clones demonstrated recognition of at least two insulin determinants, one A-loop (A8-A10) associated and the other non-loop (A4 or B chain) associated. Therefore these studies identify the molecular and antigenic basis of the Ir gene complementation seen in the response to beef insulin of (B10.A X bm12)F1 hybrids.

The development of sensitive and specific radioimmunoassays for leukotrienes.

Radioimmunoassays for leukotriene C4 (LTC4) and for leukotriene B4 (LTB4) have been developed. LTC4 was conjugated with thiolated hemocyanin (Keyhole Limpet) (KLH) using 6-(N-maleimido)hexanoic acid chloride as coupling agent. LTB4 was converted to its hydrazide derivative, via the delta-lactone and the hydrazide was similarly coupled with thiolated KLH using 6-(N-maleimido)hexanoic acid chloride as coupling agent. These conjugates were used to consistently raise high titres of anti-leukotriene antibodies in rabbits. 14,15-[3H]-LTC4 was prepared by total synthesis via two routes. 14,15-[3H]-LTB4 was prepared by total synthesis. The assay for LTC4 recognizes LTC4, LTD4 and LTF4, and to a lesser extent, LTE4 with a detection limit of ca. 0.1 pmoles LTC4 per mL of sample. The assay for LTB4 is highly specific and has a similar detection limit.

Measuring leukotrienes of slow reacting substance of anaphylaxis: development of a specific radioimmunoassay.

Rabbits were immunized with leukotriene C4 (LTC4) coupled to thiolated keyhole limpet hemocyanin (KLH) by using 6-N-maleimidohexanoic acid as a spacer molecule. Immune serum was obtained with 7.9 nmol of LTC4-specific immunoglobulin per milliliter and a mean association constant of 2.1 X 10(9) M-1. A radioimmunoassay was developed that detected 0.1 pmol of LTC4 per 1-ml sample. LTD4 and LTE4, three isomers of LTC4, the sulfones of LTC4, LTD4, and LTE4, and one isomer of LTD4 reacted to varying degrees in the assay. A number of other structurally related compounds, such as LTB4 and 5-HETE, did not react. Conditions were established to determine LTC4 levels in human plasma without loss of LTC4 during sample preparation and without the need for extraction procedures before the measurement of LTC4.

Regulation of immune response by preadministration of cells briefly pulsed with antigen in vitro. I. Suppression of IgE antibody response by antigen pulsed spleen cells.

The intravenous administration of syngeneic spleen cells (SPCs) briefly pulsed with antigen in vitro, results in a profound state of IgE antibody unresponsiveness. In Balb/c mice, the primary response of anti-DNP, anti-beef insulin and anti-ovalbumin IgE antibody is completely suppressed by the administration of antigen-pulsed spleen cells, 1 X 10(7), 5 X 10(7) and 1 X 10(8), respectively. This suppression is antigen specific and effects both primary and secondary immune responses. Furthermore, the immune response to dinitrophenylated Keyhole limpet hemocyanin (DNP-KLH) is most extensively suppressed by DNP-KLH pulsed SPCs, intermediately suppressed by KLH-pulsed SPCs and minimally suppressed by dinitrophenylated mouse gamma globulin or dinitrophenylated mouse serum albumin pulsed SPCs. Suppressing directly cells specific for hapten and carrier, hapten carrier protein pulsed SPCs would caused the additive suppressive effect. The suppression is induced strongly by the intravenous administration of antigen pulsed spleen cells, slightly by the subcutaneous administration and is not induced by the intravenous administration of antigen solution in phosphate buffer saline. This suppression may be mediated by either of two different mechanisms: one of them is responsible for the immediate tolerance which is induced without any suppressor cells 1 day after the administration of antigen pulsed SPCs, and the other is responsible for the suppression transferred by suppressor cells or factors to normal mice 7 days after the administration of antigen pulsed SPCs. This method in which IgE antibody response is suppressed by the administration of cells briefly pulsed in vitro with antigen, provides a powerful tool to analyze the first step of antigen specific suppression developed in vivo by conventional antigens.

Selective loss of antigen-specific Ir gene function in IA mutant B6.C-H-2bm12 is an antigen presenting cell defect.

Immune responses to several soluble antigens were compared between B6.C-H-2bm12 mutant and wild-type B6 mice by using a lymph node T-cell proliferation assay. B6.C-H-2bm12 mice failed to respond to beef insulin whereas other IA gene-controlled responses, such as response to poly(L-Tyr, L-Glu)--poly(DL-Ala, L-Lys) and collagen, were indistinguishable between mutant and wild-type mice. The responses to multideterminant antigens such as ovalbumin and purified protein derivative of tuberculin were also found to be comparable in B6.C-H-2bm12 and B6 mice, thus indicating that this mutation resulted in a selective loss of the ability to respond to a certain antigen(s)--e.g., beef insulin. Populations depleted of adherent cells have been used to examine the mechanism by which Ia molecules mediate Ir gene control of antigen recognition. We show that the nonresponsiveness to beef insulin in the mutant mouse is the result of defective antigen presentation. In addition, we find that F1 hybrids between two nonresponders--B6.C-H-2bm12 and B10.A or B10.AKM (IAk) mice--become responders to beef insulin, thus demonstrating gene complementation. These findings taken together with other serologic and biochemical studies in the B6.C-H-2bm12 present convincing genetic evidence for the direct association of the A beta polypeptide chain of the Iab molecules with the expression of immune responsiveness to beef insulin. Study of the B6.C-H-2bm12 mouse should provide new insight into the cellular and molecular mechanisms by which Ir genes determine the nature of the immune response.

Immune response gene control of determinant selection. III. Polypeptide fragments of insulin are differentially recognized by T but not by B cells in insulin immune guinea pigs.

Synthetic polypeptides corresponding to restricted regions of the B chain of insulin were used to evaluate immune response gene control of guinea pigs immune to native insulin. The amino acids necessary for recall of immune memory were assessed at the level of the T cell by use of peptides 8 to 16 amino acids in length, representative of the amino terminus of the insulin B chain to induce antigen-specific proliferation and help for antibody formation. A single histidine residue in the 10th position of the B chain is critical for T cell activation. In addition, immune response genes operating in the macrophage discern the presence or absence of this residue and activate the appropriate T cell clones. Although receptor V region sharing may exist for T and B cells immune to globular proteins, it cannot be demonstrated by antigen specificity, since T proliferation and generation of T helper cells in response to intact insulin can be elicited by synthetic fragments that do not correspondingly induce antibodies that recognize the native molecule.

I-A mutation resulted in a selective loss of an antigen-specific Ir gene function.

The immune responses to several antigens were compared in the I-A mutant mouse strain B6.C-H-2bm12 and the wild-type strain C57BL/6. With a lymph node cell proliferation assay, the response to two of these antigens, beef insulin and (TG)A-L, was demonstrated to be controlled by a gene in the I-Ab region. B6.C-H-2bm12 mice failed to respond to beef insulin, while their responses to (TG)A-L, DNP-OVA and PPD were comparable with those of the wild-type strain C57BL/6. Taken together with previous studies, these data suggest that the product of a single pleiotropic I-A gene, an Ia molecule, functions as a histocompatibility, Ia, and MLR antigen, as well as a necessary component for Ir gene function. Furthermore, the data reported here demonstrate that Ia molecules have multiple functional "Ir determinants," one of which has been altered in the B6.C-H-2bm12 mutant. The B6.C-H-2bm12 mice, therefore, represent a powerful analytical tool for the understanding of the cellular and molecular basis for Ir gene control of the immune response.