Pharmacologic treatment of tremor

Tremor is a common neurologic symptom that can also be incapacitating to the patient, so effective therapy is needed. The causes of tremor are heterogeneous. Essential tremor (ET) and the tremor associated with Parkinson's disease (PD) are the most common encountered in clinical practice. Beta-adrenergic blockers and primidone remain the mainstay of treatment for ET, whereas carbidopa/levodopa and anticholinergics are most beneficial in PD. However, the efficacy of various other medications has been studied in ET and PD, and also in patients with tremor resulting from other conditions, with varying results.

A new monoclonal antibody, mAb 4A12, identifies a role for the glycosaminoglycan (GAG) binding domain of RANTES in the antiviral effect against HIV-1 and intracellular Ca2+ signaling

The beta-chemokine RANTES (regulated on activation, normal T cell expressed and secreted) suppresses the infection of susceptible host cells by macrophage tropic strains of HIV-1. This effect is attributed to interactions of this chemokine with a 7-transmembrane domain receptor, CCR5, that is required for virus-cell fusion and entry. Here we identify domains of RANTES that contribute to its biological activities through structure-function studies using a new monoclonal antibody, mAb 4A12, isolated from mice immunized with recombinant human RANTES. This monoclonal antibody (mAb) blocked the antiviral activity of RANTES in infectivity assays with HIV-1Bal, and inhibited the mobilization of intracellular Ca2+ elicited by RANTES, yet recognized this chemokine bound to cell surfaces. Epitope mapping using limited proteolysis, reversed phase high-performance liquid chromatography, and mass spectrometry suggest that residues 55-66 of RANTES, which include the COOH-terminal alpha-helical region implicated as the glycosaminoglycan (GAG) binding domain, overlap the determinant recognized by mAb 4A12. This is supported by affinity chromatography studies, which showed that RANTES could be eluted specifically by heparin from a mAb 4A12 immunoaffinity matrix. Removal of cell surface GAGs by enzymatic digestion greatly reduced the ability of mAb 4A12 to detect RANTES passively bound on cell surfaces and abrogated the ability of RANTES to elicit an intracellular Ca2+ signal. Taken together, these studies demonstrate that the COOH-terminal alpha-helical region of RANTES plays a key role in GAG-binding, antiviral activity, and intracellular Ca2+ signaling and support a model in which GAGs play a key role in the biological activities of this chemokine.

Class restriction of cephalosporin use to control total cephalosporin resistance in nosocomial Klebsiella

CONTEXT

Resistance to most or all cephalosporin antibiotics in Klebsiella species has developed in many European and North American hospitals during the past 2 decades.

OBJECTIVE

To determine if restriction of use of the cephalosporin class of antibiotics would reduce the incidence of patient infection or colonization by cephalosporin-resistant Klebsiella.

DESIGN

A before-after comparative 2-year trial.

SETTING

A 500-bed, university-affiliated community hospital in Queens, NY.

PATIENTS

All adult medical and surgical hospital inpatients.

INTERVENTION

A new antibiotic guideline excluded the use of cephalosporins except for pediatric infection, single-dose surgical prophylaxis, acute bacterial meningitis, spontaneous bacterial peritonitis, and outpatient gonococcal infection. All other cephalosporin use required prior approval by the infectious disease section.

MAIN OUTCOME MEASURE

Incidence of patient infection or colonization by ceftazidime-resistant Klebsiella during 1995 (control period) compared with 1996 (intervention period).

RESULTS

An 80.1% reduction in hospital-wide cephalosporin use occurred in 1996 compared with 1995. This was accompanied by a 44.0% reduction in the incidence of ceftazidime-resistant Klebsiella infection and colonization throughout the medical center (P<.01), a 70.9% reduction within all intensive care units (P<.001), and an 87.5% reduction within the surgical intensive care unit (P<.001). A concomitant 68.7% increase in the incidence of imipenem-resistant Pseudomonas aeruginosa occurred throughout the medical center (P<.01). All such isolates except one were susceptible to other antibiotics.

CONCLUSION

Extensive cephalosporin class restriction significantly reduced nosocomial, plasmid-mediated, cephalosporin-resistant Klebsiella infection and colonization. This occurred at the price of increased imipenem resistance in P aeruginosa, which remained susceptible to other agents. Thus, an overall reduction in multiply-resistant pathogens was achieved within 1 year.

Integrin-mediated interactions influence the tissue specificity of CD8+ cytolytic T lymphocytes

We previously reported that CD8+ cytotoxic T lymphocytes (CTL) elicited in response to allogeneic renal epithelial cells (anti-REC CTL) preferentially lyse REC targets as compared to conventional lymphoid cell (LC) targets. It is often tacitly assumed that such cell type specificity results from CTL recognition of tissue-restricted MHC/peptide complexes. However, we herein report that anti-REC CTL uniquely express CD103, an integrin with known specificity for the epithelial cell-restricted ligand E-cadherin, and are deficient in expression of CD11a (LFA-1), an integrin known to play a critical accessory role in promoting lysis of LC targets. We demonstrate that CD8+ CTL clones with disparate CD103/CD11a phenotypes but identical specificities for allo-MHC/peptide can exhibit marked differences in cell type specificity. Antibody blocking studies provided direct evidence that CD103 serves as an accessory molecule that promotes lysis of REC targets. Taken together, these data indicate that integrin-mediated accessory interactions can influence the capacity of CD8+ CTL to discriminate between different cell types.

Signal transduction in human macrophages by gp83 ligand of Trypanosoma cruzi: trypomastigote gp83 ligand up-regulates trypanosome entry through the MAP kinase pathway

We found that Trypanosoma cruzi trypomastigote cloned surface ligand (gp83 trans-sialidase) signals human macrophages to up-regulate parasite entry by inducing tyrosine phosphorylation of MAP kinase. Preincubation of human macrophages with r-gp83 transsialidase significantly enhanced both the percentage of phagocytosed trypanosomes and the number of trypanosomes per cell in a concentration dependent fashion. Incubation of r.gp83 with macrophages induced tyrosine phosphorylation of several macrophage proteins. This enhancement was inhibited by genistein, a tyrosine kinase inhibitor. The r-trypanosome ligand enhanced tyrosine phosphorylation of ERK1 and this enhancement was specifically inhibited by the inhibitor of MAP kinase phosphorylation, PD 98059, or by genistein. PD 98050 or genistein also inhibited the enhancement of trypomastigote uptake by macrophages induced by the r-ligand. These results indicate that T. cruzi uses a novel mechanism to signal cells in the process of trypanosome entry, via a secreted trypanosome ligand which signals macrophages through the MAP kinase pathway.

Interferon-gamma increases expression of chemokine receptors CCR1, CCR3, and CCR5, but not CXCR4 in monocytoid U937 cells

Chemokine receptors (CR), which can mediate migration of immune cells to the site of inflammation, also function as coreceptors for human immunodeficiency virus (HIV) entry into CD4+ T lymphocytes and antigen-presenting cells. We demonstrate here that interferon-gamma (IFN-gamma) increases the expression of chemokine receptors CCR1, CCR3, and CCR5 in monocytoid U937 cells as detected by cell surface molecule labeling and mRNA expression, as well as by intracellular calcium mobilization and cell migration in response to specific ligands. The increased expression of these chemokine receptors also results in an enhanced HIV-1 entry into cells. Our data provide evidence for a relationship of cellular pathways that are induced by IFN-gamma with those that regulate chemokine receptor expression.

Naive human T cells develop into Th1 or Th0 effectors and exhibit cytotoxicity early after stimulation with Leishmania-infected macrophages

Studies of human disease suggest that naturally acquired immunity is the predominant outcome of Leishmania infection. Normally protective immune mechanisms activated during asymptomatic or self-healing infections may be minimal in patients who develop disease. To explore early immune responses, an in vitro model of human Leishmania infection was developed in which naive T cells were sensitized with Leishmania-infected macrophages. An analysis of Leishmania-specific cytokine production by these T cell lines revealed that most individuals developed Th1 or Th0 responses early after infection. Infected macrophages from Th1 responders produced interleukin-12. Th0 responders who produced little or no endogenous interleukin-12 could be converted to the Th1 phenotype by addition of interleukin-12 during priming. Finally, infection-sensitized T cells specifically lysed Leishmania-infected macrophages. Thus, this in vitro model system can be used to delineate protective human immune responses against Leishmania induced early after infection.

Mycobacterium tuberculosis specimen contamination revisited: the role of laboratory environmental control in a pseudo-outbreak

OBJECTIVE

To investigate suspected pseudo-outbreaks of Mycobacterium tuberculosis (MTB) during August 1994 and July 1995 among patients who did not have clinical findings consistent with tuberculosis.

DESIGN

Retrospective and prospective surveys of all clinical and laboratory data using standard epidemiological tools and DNA fingerprinting.

SETTING

A university-affiliated community hospital.

PATIENTS

Those with positive MTB cultures during periods when we noted that the number of MTB positive cultures greatly outnumbered the usual monthly average (retrospective analysis, 1994) and patients with positive MTB cultures without clinical findings consistent with tuberculosis (prospective survey, 1995).

RESULTS

Epidemiological and molecular studies revealed specimen cross-contamination in the laboratory due to a faulty exhaust hood. Improvement in laboratory ventilation and change of the implicated hood prevented further specimen contamination.

CONCLUSIONS

The identification of positive MTB cultures from patients without clinical evidence of tuberculosis should be a signal to suspect laboratory contamination and implement control measures. These should include a thorough epidemiological investigation, DNA fingerprint analysis, and an environmental inspection.

Analysis of pallidotomy lesion positions using three-dimensional reconstruction of pallidal lesions, the basal ganglia, and the optic tract

OBJECTIVE

To assess the position of radiofrequency pallidotomy lesions placed using microelectrode stimulation and cellular recordings in relation to a stereotactically defined starting point. Radiofrequency lesion locations were also evaluated in relation to the putamen, posterior limb of the internal capsule, and optic tract.

METHODS

Magnetic resonance images obtained from 23 patients with Parkinson's disease who underwent pallidotomy at the University of Kansas Medical Center were analyzed. Using computerized techniques, lesion positions in relation to the midcommissural point and a hypothetical starting point were determined. Data segmentation and three-dimensional reconstruction of pallidal lesions, the internal capsule, and the optic tract allowed assessment of lesion position in relation to internal anatomy. Clinical outcome of pallidotomy was assessed using both the Unified Parkinson's Disease Rating Scale and the Dementia Rating Scale.

RESULTS

Pallidal lesions were usually placed anterior and dorsal to the stereotactically defined starting point. The position of pallidal lesions in the men were observed, in four trials, to be significantly more dorsal than the lesions in the women. The outer zone of the lesion was usually adjacent to the internal capsule and the putamen and relatively close to the optic tract. The inner zone of the lesion was usually several millimeters removed from anatomic boundaries of the putamen, internal capsule, and optic tract. Patients achieved favorable outcomes, with reduced dyskinesias and "off" time and improvement of their Parkinsonian symptoms, as evidenced by clinical assessment, the Unified Parkinson's Disease Rating Scale, and the Dementia Rating Scale.

CONCLUSION

Microelectrode stimulation and cellular recordings usually led to a final pallidotomy lesion position that deviated from the stereotactically defined starting point. The pallidotomy lesions in the men were observed to be more dorsal than the lesions in the women. Clinical outcomes were not correlated with either lesion location relative to the starting point or distances between the pallidal lesion and the putamen, internal capsule, or optic tract. Kinesthetically responsive cells may be localized generally more anterior and dorsal to the starting point (within the globus pallidus) and may be grouped variably from patient to patient in relation to other basal ganglia structures. Although the primary lesion site is most likely within the sensorimotor region of the globus pallidus internus, the more dorsal locations of responsive cell groups may indicate that some lesion sites may be localized within the globus pallidus externus.

Protective immunity against Plasmodium yoelii malaria induced by immunization with particulate blood-stage antigens

The Plasmodium yoelii murine model was used to test several combinations of blood-stage antigens and adjuvants for the ability to induce immunity to blood-stage malaria. Upon fractionation of whole blood-stage antigen into soluble and insoluble components, only the particulate antigens (pAg) induced protective immune responses. Of a number of adjuvants tested, Quil A was the most effective. Immunization with pAg plus Quil A induced solid protection against nonlethal and lethal P. yoelii challenge infection. Analysis of cytokine production revealed mRNA for Th1-type cytokines (interleukin 2 [IL-2] and gamma interferon) as well as Th2-type cytokines (IL-4 and IL-10) in the spleens of both protected and susceptible animals. The data suggested that the protective pAg response was associated with the earlier production of cytokine mRNA with a Th2 phenotype somewhat favored. Immunization of B-cell-deficient JHD mice indicated that the protection against P. yoelii induced by pAg immunization was B cell dependent. Although immunization with pAg plus Quil A increased the levels of antigen-specific antibodies of all four immunoglobulin G (IgG) isotypes, protection correlated most closely with the presence of IgG1 and IgG2b antibodies. Sera from pAg-plus-Quil A-immunized animals recognized only a limited subset of six to eight distinct P. yoelii antigens, primarily associated with the pAg fraction. These results provide the basis for the identification and characterization of potential vaccine antigens, selected solely for their ability to immunize against blood-stage malaria.

Magnetic resonance image evaluation of pallidotomy lesions: a volumetric and shape analysis

Determination of acute pallidotomy-produced lesion volumes, pre- and postpallidotomy globus pallidus (GP) volumes, and assessment of lesion shape using magnetic resonance (MR) imaging-based computerized segmentation (contouring) and three-dimensional rendering was made in 19 patients. Magnetic resonance image slice thickness (1.5 mm or 6 mm) was not found to be a significant factor influencing contour-based pallidotomy lesion volume estimates. Previously reported lesion volumes produced by pallidotomy have often been estimated using the ellipsoid volume formula. Using 1.5-mm-thick MR sections, contour-based pallidotomy-produced lesion volumes were significantly different from those volumes estimated by the ellipsoid formula. Globus pallidus volumes, estimated by contouring T2-weighted MR images, were bilaterally similar (2.4 ± 0.37 ml [right]; 2.2 ± 0.45 ml [left]). Postoperative GP volumes were found on the contralateral, unlesioned side to be 2 ± 0.45 ml and on the lesioned side to be 1.25 ± 0.45 ml. Using the contralateral, unlesioned side as a reference volume, approximately 39 ± 14% of the GP was visibly affected on the lesioned side. Seventeen of 18 patients had a favorable outcome with reduced dyskinesias and "off" time with improvement in parkinsonian symptoms.

Analysis of computerized three-dimensional rendering of pallidotomy-produced lesions based on MR images showed no relationship between lesioning technique and resulting lesion shape. Important factors in the volumetric analysis of pallidotomy lesions are identified and allow reasonable assessment of the pallidotomy lesion volume and shape and the extent of the affected GP.

A daily flowsheet for an outpatient bone marrow transplant treatment center

PURPOSE/OBJECTIVES

To develop a flowsheet for an outpatient bone marrow transplant treatment center that would decrease the time required to complete documentation and facilitate verbal reports.

DATA SOURCES

Oncology nursing standards of care, clinical experience, and published books and articles.

DATA SYNTHESIS

A comprehensive daily flowsheet was developed to provide consistency in assessments and documentation of a complex outpatient population.

CONCLUSIONS

The implementation of the new flowsheet decreased the amount of nursing time spent on written documentation and verbal reports. Patients' daily assessments are tracked more easily using this form.

IMPLICATIONS FOR NURSING PRACTICE

Staff satisfaction can be increased by reducing the amount of time spent on patient documentation.

rK39: a cloned antigen of Leishmania chagasi that predicts active visceral leishmaniasis

The diagnosis of visceral leishmaniasis (VL), a serious and often fatal parasitic disease caused by members of the Leishmania donovani complex, remains problematic. Current methods rely on clinical criteria, parasite identification in aspirate material, and serology. The latter methods use crude antigen preparations lacking in specificity. A previously described cloned antigen, rK39, of Leishmania specific for all members of the L. donovani complex (L. chagasi, L. donovani, L. infantum) was very useful in the serodiagnosis by ELISA of both human and canine VL. The present study demonstrated that rK39 seroreactivity correlated with active disease. The sera from early or self-healing infected subjects reacted with leishmanial lysate and were generally nonreactive with rK39. These data demonstrate the utility of rK39 in the serodiagnosis of VL and as an indicator of active disease.

Critical pathway for administering high-dose chemotherapy followed by peripheral blood stem cell rescue in the outpatient setting

PURPOSE/OBJECTIVES

To explain the rationale and process of outpatient critical pathway development for sequential high-dose chemotherapy followed by peripheral blood stem cell transplantation.

DATA SOURCES

Published books and journal articles.

DATA SYNTHESIS

Complex treatment for patients with metastatic breast cancer is shifting to the outpatient area. To make this therapy safe and cost effective, a process for monitoring this type of outpatient care needs to be developed.

CONCLUSIONS

Collaboration with a multidisciplinary team is important in ensuring quality of care for complex outpatient treatment protocols. Critical pathway development can serve as a road map for delivering this care.

IMPLICATIONS FOR NURSING PRACTICE

As team leaders, nurses should oversee the critical pathway development and implementation. Nurses also should maintain their role of patient advocacy through monitoring pathway compliance.

Denver Potable Water Reuse Demonstration Project: comprehensive chronic rat study

The health effects testing program for the Denver Water Department's Potable Water Reuse Demonstration Project was designed to evaluate the relative health effects of highly treated reclaimed water derived from secondary wastewater in comparison with Denver's present high-quality drinking water. The 1 x 10(6) gal/day treatment plant provided 500-fold concentrates of water that had been treated by multiple processes to remove microbial and chemical contaminants. Fischer 344 rats were exposed to the complex mixture solutions for up to 2 yr to evaluate chronic toxicity and oncogenicity effects. The following parameters were evaluated: clinical observations, survival rate, growth, food and water consumption, haematology, clinical chemistry, urinalysis, organ weights, gross autopsy and histopathological examination of all lesions, major tissues and organs. Clinical pathology, gross pathology, and microscopic pathology conducted at wk 26 and 65 and at the end of the study did not reveal any findings that could be considered to be treatment related. Administration of drinking water concentrates at up to 500 times the original concentration in the original water samples to F344 rats for up to 104 wk did not result in any overt toxicological or carcinogenic effects.

Antigens shared by Leishmania species and Trypanosoma cruzi: immunological comparison of the acidic ribosomal P0 proteins

Patients with visceral leishmaniasis produce high levels of immunoglobulin, but the specificities of antibodies produced are not well characterized. In an effort to identify leishmania antigens that are specific to Leishmania species or are cross-reactive with other parasitic protozoa, we have cloned and characterized full-length genomic and cDNA clones encoding a Leishmania chagasi acidic ribosomal antigen, LcP0, recognized during human infections. The protein is homologous to the Trypanosoma cruzi and human ribosomal proteins TcP0 and HuP0, respectively. Unlike most higher eukaryotes, but similar to TcP0, LcP0 has a C-terminal heptapeptide sequence resembling those of the archaebacterial acidic (P-like) proteins. The highly charged C-terminal acidic domain of LcP0 contains a serine residue typically found in most eukaryotes but lacking in all T. cruzi P proteins we have characterized thus far. L. chagasi-infected individuals as well as those with T. cruzi infections have antibodies cross-reactive with recombinant LcP0 and TcP0 as well as HuP0. However, the properties of anti-P0 antibodies in T. cruzi and L. chagasi infection sera are quite different. Through the use of synthetic peptides, we showed that while T. cruzi infection anti-TcP0 antibodies are exclusively directed against the C-terminal domain of TcP0, L. chagasi infection sera contain antibodies reactive with epitopes other than the C-terminal sequence of LcP0. Thus, anti-LcP0 antibodies in L. chagasi infection sera represent the first characterized deviation from the restricted immunodominant C-terminal epitope involved in the generation of anti-P0 antibodies following infection or autoimmune diseases.

Serodiagnosis of Chagas' disease by enzyme-linked immunosorbent assay using two synthetic peptides as antigens

An enzyme-linked immunosorbent assay (ELISA) was developed for detecting antibodies against Trypanosoma cruzi. Two synthetic T. cruzi peptides, TcD and PEP2, were used. The specificity and sensitivity of the peptide ELISA were determined with 260 serum samples from individuals living in an area in which Chagas' disease is endemic. ELISAs were performed with the peptides singly or in combination. The evaluation of these tests showed that 168 (93.8%) of 179 serum samples from T. cruzi-infected patients were positive when TcD peptide was used as antigen; 164 (91.6%) samples were positive with PEP2, and 178 (99.4%) samples were positive when the two peptides were combined. Thus, the sensitivity of the ELISA using the two peptides exceeded 99%. The specificity was evaluated by using a panel of 118 serum samples that included samples from 81 individuals living in an area of endemicity with negative serology for Chagas' disease and from 37 patients from areas in which T. cruzi was not endemic but with other pathologies, such as leishmaniasis, tuberculosis, and leprosy. Only two false-positive serum samples were found in this group of individuals, giving a test specificity of more than 98%. Because these peptides can be synthesized and are very stable at room temperature, the use of such reagents can improve the standardization and reproducibility of ELISAs for the serodiagnosis of T. cruzi infection.

A comparison of the efficacy and duration of action of topically applied proxymetacaine using a novel ophthalmic delivery system versus eye drops in healthy young volunteers

A novel ophthalmic drug delivery system (NODS) has been developed to give precise and controlled delivery of a drug to the eye. The drug is incorporated into a polyvinyl alcohol flag attached to a carrier. When applied to the eye the flag detaches and gradually dissolves, releasing the drug. We investigated corneal anaesthesia produced by different concentrations of proxymetacaine NODS, and conventional eye drops. Subjects consisted of 28 normal males (mean age 25.3 (SD 3.9) years). Corneal touch sensitivity was measured with a biomicroscope mounted Cochet-Bonnet aesthesiometer. Each subject attended for two visits separated by 7 days. On each visit each eye randomly received one of four proxymetacaine preparations: 44 micrograms, 74 micrograms, 124 micrograms NODS, or 35 microliters of 0.5% proxymetacaine drops (175 micrograms). Corneal touch sensitivity was measured before, and at 1, 2, 5, 10, 15, 20, 30, 45, and 60 minutes following instillation. Complete anesthesia was achieved in the majority of subjects within 1 minute of instillation. The lowest NODS dose (44 micrograms) produced longer lasting anaesthesia than the 35 microliters drop (175 micrograms) (p < 0.05). Higher NODS doses produced a correspondingly greater increase in the duration of anaesthesia. The greater bioavailability achieved by this vehicle allows much lower drug concentrations to be used, reducing the likelihood of systemic adverse reactions.

Molecular cloning and characterization of a 42-kDa protein phosphatase of Leishmania chagasi

Using rabbit serum raised against a potent T cell-stimulating antigen fraction of Leishmania chagasi promastigotes, we have cloned and expressed the Leishmania type 2C serine/threonine protein phosphatase, LcPP2C. LcPP2C was shown to be present as a 42-kDa protein in both the infective promastigote and tissue amastigote stages of L. chagasi and Leishmania amazonensis. DNA hybridization studies established the close conservation of LcPP2C among eight of eight geographically diverse species of Leishmania which cause a spectrum of human diseases. To support the relationship between LcPP2C and mammalian type 2C protein phosphatases observed through predicted amino acid sequence comparisons, we expressed enzymatically active rLcPP2C in Escherichia coli. We demonstrated that purified rLcPP2C readily dephosphorylated [32P]casein, an activity dependent on Mg2+ and insensitive to okadaic acid. In agreement with studies of rat liver PP2C, activity was maintained when Mg+2 was replaced with Mn+2 but not with Ca2+. As these parameters are characteristic of the eukaryotic type 2C serine/threonine protein phosphatases, LcPP2C can be classified as a member of this protein family. We further showed that of the four major classes of eukaryotic serine/threonine protein phosphatases, PP2C-and PP1-like activities, are readily detectable in Leishmania.

Characterization of responses of normal human T cells to Trypanosoma cruzi antigens

The stimulation of normal human PBMC by Trypanosoma cruzi Ag was analyzed. PBMC showed significant in vitro proliferation in response to parasite lysate (Tct), with stimulation indices ranging from 10 to 400, peaking at 6 to 7 days. The cells stimulated with Tct produced significant levels of IL-2. To determine which cells proliferated in response to Tct, PBMC were separated into T- and B-enriched cell populations. Purified T cells, but not B cells, proliferated strongly to Tct. The T cell response required APC and was processing dependent. T cell lines generated against Tct proliferated in response to parasite lysate only in the presence of autologous APC and produced IL-2, IL-6, and IFN-gamma but not IL-4 in response to PMA plus ionomycin. Although there were a significant number of CD45Ra+ cells, the majority of the cells in these T cell lines were CD45Ro+. The V beta usage of Tct-responding T cells was heterogeneous, with most V beta genes represented among the responding cells. An immunodominant repeat Ag (TcD) and a ribosomal phosphoprotein (P0) of T. cruzi elicited strong proliferative responses in all subjects tested. These data indicate the presence of T cell-stimulatory Ag in Tct, characterized by nonpreferential usage of the V beta gene families. The strong stimulation of normal human PBMC by Tct may contribute to immunologic alterations seen in T. cruzi infection.

Antibody responses of visceral leishmaniasis patients to gp63, a major surface glycoprotein of Leishmania species

A major surface glycoprotein of Leishmania parasites, gp63, is highly conserved among species and is expressed in both infective and intracellular stages. Although much is known about its role in entry and survival in host macrophages, patient antibody responses to this glycoprotein have not been well characterized. The prevalence of anti-gp63 antibody in sera of leishmaniasis patients was evaluated by ELISA. Sera from most acute visceral leishmaniasis patients (84%) from Brazil and Sudan had notably high levels of antibody to recombinant (r) gp63. Sera from other forms of leishmaniasis and from other diseases did not contain significantly elevated levels of anti-gp63 antibody. These results indicate that rgp63 might be a useful constituent of a defined serologic test for visceral leishmaniasis.

Characterization of responses of normal human T cells to Trypanosoma cruzi antigens

The stimulation of normal human PBMC by Trypanosoma cruzi Ag was analyzed. PBMC showed significant in vitro proliferation in response to parasite lysate (Tct), with stimulation indices ranging from 10 to 400, peaking at 6 to 7 days. The cells stimulated with Tct produced significant levels of IL-2. To determine which cells proliferated in response to Tct, PBMC were separated into T- and B-enriched cell populations. Purified T cells, but not B cells, proliferated strongly to Tct. The T cell response required APC and was processing dependent. T cell lines generated against Tct proliferated in response to parasite lysate only in the presence of autologous APC and produced IL-2, IL-6, and IFN-gamma but not IL-4 in response to PMA plus ionomycin. Although there were a significant number of CD45Ra+ cells, the majority of the cells in these T cell lines were CD45Ro+. The V beta usage of Tct-responding T cells was heterogeneous, with most V beta genes represented among the responding cells. An immunodominant repeat Ag (TcD) and a ribosomal phosphoprotein (P0) of T. cruzi elicited strong proliferative responses in all subjects tested. These data indicate the presence of T cell-stimulatory Ag in Tct, characterized by nonpreferential usage of the V beta gene families. The strong stimulation of normal human PBMC by Tct may contribute to immunologic alterations seen in T. cruzi infection.

Molecular characterization of a kinesin-related antigen of Leishmania chagasi that detects specific antibody in African and American visceral leishmaniasis

We report the cloning of a Leishmania chagasi antigen gene and an evaluation of leishmaniasis patient antibody responses to the recombinant protein, rK39. rK39 contains a 39-amino acid repeat that is part of a 230-kDa protein predominant in L. chagasi tissue amastigotes. Sequence analyses showed this protein, LcKin, to be related to the kinesin superfamily of motor proteins. Southern blot analyses demonstrated LcKin-related sequences in seven species of Leishmania, with conservation of the repeat between L. chagasi and Leishmania donovani. Serological evaluation revealed that 98% (56 of 57) of Brazilian and 100% (52 of 52) of Sudanese visceral leishmaniasis patients have high antibody levels to the rK39 repeat. Detectable anti-K39 antibody was virtually absent in cutaneous and mucosal leishmaniasis patients and in individuals infected with Trypanosoma cruzi. The data show that rK39 may replace crude parasite antigens as a basis for serological diagnosis of visceral leishmaniasis.

Monitoring of streptokinase resistance titre in acute myocardial infarction patients up to 30 months after giving streptokinase or anistreplase and related studies to measure specific antistreptokinase IgG

OBJECTIVE

To examine the induction of antistreptokinase antibodies after giving streptokinase or anistreplase to patients with acute myocardial infarction.

DESIGN

Patients were randomly allocated to receive either 1.5 x 10(6) IU, streptokinase or 30U anistreplase in a double blind study. Blood samples were collected immediately before treatment and subsequently at intervals up to 30 months; plasma samples were assayed for streptokinase resistance titre (functional assay) and streptokinase binding by IgG (microradioimmunoassay).

SETTING

Cardiology department in a general hospital.

PATIENTS

128 consecutive eligible patients. Samples were collected for up to one year according to a prospective design: a subsection of 47 patients was selected for intensive study over the first 14 days. After one year, all available patients (67) were sampled on one further occasion.

RESULTS

Antibody responses to streptokinase and anistreplase were similar. Streptokinase resistance titres exceeded pretreatment concentrations five days after dosing, and values peaked at 14 days. By 12 months after dosing, 92% of resistance titres (n = 84) had returned to within the pretreatment range. Antistreptokinase IgG concentrations also exceeded baseline concentrations within five days and peaked at 14 days. Half of the individual values had returned to within the pretreatment range by 12 months (n = 84) and 89% by 30 months (n = 18).

CONCLUSION

Although we cannot be sure of the clinical significance, because of the increased likelihood of resistance due to antistreptokinase antibody, streptokinase and anistreplase may not be effective if administered more than five days after an earlier dose of streptokinase or anistreplase, particularly between five days and 12 months, and increased antistreptokinase antibody may increase the risk of allergic-type reactions.

The roles of general and geriatric medicine in the provision of acute medical care for elderly patients

To determine whether there are differences between elderly patients admitted acutely to general medicine and those admitted to geriatric medical wards, and whether the patients are appropriately referred, a prospective survey of 426 consecutive patients aged 65 years or over admitted acutely to general medical and geriatric wards over a three month period was performed. A total of 286 patients were admitted to general medicine (GM) and 140 to the geriatric unit (GER). GER patients were older (81.0 v. 75.8 years) and had greater pre-morbid functional impairment and incontinence. Fewer GER patients presented with readily apparent organ specific diagnoses (56% v. 94%). Median length of stay was longer in GER patients (23 days v. 9 days). Variables independently predictive of GER admission were increasing age, increasing duration of illness, poor pre-morbid functional status and prior reliance on a carer. Length of stay was not associated with unit of admission allowing for the variables described above. GER patients are a different population. They have more chronic illness and functional impairment, and are more likely to require multidisciplinary assessment and rehabilitation in addition to treatment of presenting illness. Elderly patients are appropriately referred by General Practitioners (GPs) without a formal admissions policy.

Elderly patients and their medication: a post-discharge follow-up study

Fifty-six elderly patients (age range 65-98 years) discharged from a geriatric unit were visited at home on or after the 5th post-discharge day (median day 8) and their medication assessed. By the day of the visit, 15 of the 56 had not had a new prescription issued (27%) and 27 patients (48%) had old prescribed medication at home. Forty-one new scripts, issued by general practitioners, should have contained 128 medications if the general practitioners wished to continue unchanged the medication given on hospital discharge. Fourteen drugs (11%) had been added and 17 drugs (13%) omitted. The number of prescriptions issued unchanged was 26/41 (63%). Inaccurately labelled containers and/or changed drug names were found in 28%. Contrary to hospital advice, 47% of medications were issued in childproof containers. Poor communication between hospital and general practitioners is only part of the problem. Methods to expedite the delivery of new prescriptions should be developed.

Identification and synthesis of a major conserved antigenic epitope of Trypanosoma cruzi

A gene sequence encoding an immunodominant protein with a repetitive epitope from the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, was cloned and expressed. The identified 10-amino acid repeat is present within a high-molecular-weight trypomastigote antigen that appears specific to and conserved among T. cruzi isolates. More importantly, greater than 95% of T. cruzi infection sera, including both chronic and acute Chagas disease, contained elevated levels of antibody to a 15-amino acid synthetic peptide bearing the repetitive B-cell epitope. Considering the wide diversity of T. cruzi parasites, as well as the broad spectrum of clinical manifestations of Chagas disease, such a prevalent immune response among patients is significant and applicable to the control of Chagas disease through the diagnosis of T. cruzi infection.

Stimulation of human T lymphocytes by Leishmania lipophosphoglycan-associated proteins

Lipophosphoglycan (LPG) is a glycoconjugate present on the surface of Leishmania promastigotes that has been reported to promote intracellular survival of these parasites, to protect mice against leishmaniasis, and to elicit T cell responses in infected mice and humans. We investigated whether LPG and its components could elicit proliferative responses and cytokine secretion from leishmaniasis patient PBMC. LPG prepared by standard methods (LPG-1) stimulated patients T cells to proliferate and secrete IFN-gamma. LPG was fractionated into several components. An LPG-1-specific T cell line was shown to respond to the core region but not to the repeating saccharide units. LPG-1 was fractionated to yield an LPG-free- associated protein complex and an LPG-2 fraction that was more than 95% depleted of associated protein. The ability of LPG-2 to stimulate T cells was significantly decreased over that of LPG-1. In contrast, LPG-AP stimulated T cell proliferation and IFN-gamma production. Therefore, proteins associated with LPG were effective in eliciting patient T cell responses, whereas the glycolipid enriched moiety was weakly effective or ineffective at stimulating these responses.

Stimulation of human T lymphocytes by Leishmania lipophosphoglycan-associated proteins

Lipophosphoglycan (LPG) is a glycoconjugate present on the surface of Leishmania promastigotes that has been reported to promote intracellular survival of these parasites, to protect mice against leishmaniasis, and to elicit T cell responses in infected mice and humans. We investigated whether LPG and its components could elicit proliferative responses and cytokine secretion from leishmaniasis patient PBMC. LPG prepared by standard methods (LPG-1) stimulated patients T cells to proliferate and secrete IFN-gamma. LPG was fractionated into several components. An LPG-1-specific T cell line was shown to respond to the core region but not to the repeating saccharide units. LPG-1 was fractionated to yield an LPG-free- associated protein complex and an LPG-2 fraction that was more than 95% depleted of associated protein. The ability of LPG-2 to stimulate T cells was significantly decreased over that of LPG-1. In contrast, LPG-AP stimulated T cell proliferation and IFN-gamma production. Therefore, proteins associated with LPG were effective in eliciting patient T cell responses, whereas the glycolipid enriched moiety was weakly effective or ineffective at stimulating these responses.

Doppler echocardiography in elderly patients with ejection systolic murmurs

Thirty-nine elderly patients, mean age 77 years (range 65 to 96), with ejection systolic murmurs were studied to evaluate the functional significance of these murmurs. Subjects were evaluated clinically, by 2-D echocardiography, and by a full Doppler echocardiography study. Good quality Doppler signals were obtained in 35 subjects. Mitral regurgitation was found to be the only significant valvular lesion in 6 patients (17%). Doppler gradients in systole across the aortic valve were less than 30 mmHg in 28 subjects (80%) and were considered not significant. Gradients of greater than 30 mmHg representing significant aortic stenosis were found in 7 subjects (20%). The clinical sensitivity in detecting significant aortic stenosis was 44% and specificity was 81%. Doppler evidence of significant aortic stenosis was found in a substantial proportion of these elderly subjects. Neither clinical assessment nor 2-D echocardiography can be relied on to exclude this condition.

Human T cell responses to gp63, a surface antigen of Leishmania

gp63, an abundant and conserved leishmania cell surface protein, has been implicated in the ability of these parasitic protozoa to infect macrophages in vitro and has shown potential as a protective immunogen in mice. However, little is known regarding human immune responses to this glycoprotein Ag. In this study, human T lymphocyte responses to Leishmania amazonensis native gp63 and to recombinant gp63 (rgp63) produced in Escherichia coli were evaluated in individuals with active or cured cutaneous, mucosal or visceral leishmaniasis. Both native and rgp63 elicited strong proliferative responses in all patients tested. In addition, IFN-gamma was produced in response to stimulation with both forms of the protein. T cell lines generated from PBMC by stimulation with native or rgp63 were phenotypically similar, and proliferated and produced IFN-gamma in response to stimulation with both forms of the molecule. These results suggest that gp63 is a strong T cell immunogen and that the recombinant and native forms can elicit the same type of T cell response from infected patients. In order to compare the immunogenic properties of these two forms of gp63, PBMC from naive (uninfected) donors were sensitized in vitro with native or rgp63. T cell lines generated against rgp63 proliferated in response to rgp63, but failed to proliferate in response to native gp63 or to promastigote lysate. Thus, rgp63 was effective in eliciting T cell responses from patients with active or cured leishmania infection, but did not effectively induce T cell responses under the conditions used.

Human T cell responses to gp63, a surface antigen of Leishmania

gp63, an abundant and conserved leishmania cell surface protein, has been implicated in the ability of these parasitic protozoa to infect macrophages in vitro and has shown potential as a protective immunogen in mice. However, little is known regarding human immune responses to this glycoprotein Ag. In this study, human T lymphocyte responses to Leishmania amazonensis native gp63 and to recombinant gp63 (rgp63) produced in Escherichia coli were evaluated in individuals with active or cured cutaneous, mucosal or visceral leishmaniasis. Both native and rgp63 elicited strong proliferative responses in all patients tested. In addition, IFN-gamma was produced in response to stimulation with both forms of the protein. T cell lines generated from PBMC by stimulation with native or rgp63 were phenotypically similar, and proliferated and produced IFN-gamma in response to stimulation with both forms of the molecule. These results suggest that gp63 is a strong T cell immunogen and that the recombinant and native forms can elicit the same type of T cell response from infected patients. In order to compare the immunogenic properties of these two forms of gp63, PBMC from naive (uninfected) donors were sensitized in vitro with native or rgp63. T cell lines generated against rgp63 proliferated in response to rgp63, but failed to proliferate in response to native gp63 or to promastigote lysate. Thus, rgp63 was effective in eliciting T cell responses from patients with active or cured leishmania infection, but did not effectively induce T cell responses under the conditions used.

Left ventricular hypertrophy in hypertension

Major advances in left ventricular hypertrophy (LVH) and hypertension have occurred in recent years. The ability to diagnose LVH has been improved by echocardiography, and with this technique it has been shown that evidence of LVH is an important independent risk factor for cardiovascular disease. The major cause of death in patients with hypertension and LVH is coronary artery disease. Therefore an understanding of the interrelationships between these two disorders is fundamental, and it is now clear that the hypertrophied ventricle is vulnerable to myocardial ischemia. Appreciation of the mechanisms of sudden death has also increased, although the exact situation in patients with LVH remains to be clarified. Regression of LVH is known to occur with the use of several different antihypertensive drugs. Recent studies indicate that the calcium blocking agent nicardipine, in addition to beta-blocking drugs and angiotensin-converting enzyme inhibitors, brings about LVH regression without any deterioration of left ventricular function. However, further studies are needed to assess the long-term benefits of this regression.

A comparison of the pharmacokinetic properties of streptokinase and anistreplase in acute myocardial infarction

1. The pharmacokinetics of streptokinase (SK) and anistreplase in conventional dosage regimens of 1.5 x 10(6) i.u. of SK infused over 60 min and 30 units of anistreplase over 5 min were studied in 24 consecutive patients presenting with acute myocardial infarction, using a functional bioassay to assess concentrations. 2. The two agents were found to have similar volumes of distribution (5.68 and 5.90 l), but SK was cleared significantly more rapidly than anistreplase, resulting in a shorter terminal phase half-life (0.61 vs 1.16 h) and a shorter mean residence time (0.76 vs 1.55 h).

Characterization of a membrane antigen of Leishmania amazonensis that stimulates human immune responses

To investigate human immune responses to defined leishmania Ag we have begun to characterize biochemically and immunologically, an abundant 42-kDa surface Ag of Leishmania amazonensis, a causative agent of human leishmaniasis. We have shown that this Ag, La gp42, is expressed on the surface of L. amazonensis promastigotes, being anchored to the membrane by a glycosyl-phosphatidylinositol moiety. As demonstrated by lectin blotting studies, La gp42 is glycosylated, binding both Con A and wheat germ agglutinin. Immunologically, La gp42 is strongly recognized by sera from patients with different forms of leishmaniasis as well as by patients with Chagas' disease. In addition, we show that purified La gp42 stimulates the proliferation of human T lymphocytes obtained from several leishmaniasis patients. Finally, the N-terminal sequence of La gp42 was obtained and a serologically cross-reactive 42-kDa protein with a homologous sequence was identified in Leishmania major.

Characterization of a membrane antigen of Leishmania amazonensis that stimulates human immune responses

To investigate human immune responses to defined leishmania Ag we have begun to characterize biochemically and immunologically, an abundant 42-kDa surface Ag of Leishmania amazonensis, a causative agent of human leishmaniasis. We have shown that this Ag, La gp42, is expressed on the surface of L. amazonensis promastigotes, being anchored to the membrane by a glycosyl-phosphatidylinositol moiety. As demonstrated by lectin blotting studies, La gp42 is glycosylated, binding both Con A and wheat germ agglutinin. Immunologically, La gp42 is strongly recognized by sera from patients with different forms of leishmaniasis as well as by patients with Chagas' disease. In addition, we show that purified La gp42 stimulates the proliferation of human T lymphocytes obtained from several leishmaniasis patients. Finally, the N-terminal sequence of La gp42 was obtained and a serologically cross-reactive 42-kDa protein with a homologous sequence was identified in Leishmania major.

An improved serodiagnostic procedure for visceral leishmaniasis

The enzyme-linked immunosorbent assay (ELISA) is a sensitive and specific serodiagnostic method for leishmaniasis. In this report, we describe how this versatile assay can be improved by the use of protein A or protein G conjugates for the specific detection of Leishmania antibody in the sera of patients with visceral leishmaniasis. In direct comparisons with anti-immunoglobulin conjugate, enzyme-linked protein A gave significantly higher absorbance values for positive sera without a corresponding increase in absorbance values for sera from normal individuals or from patients with other diseases known to cross-react with leishmaniasis. The effect was to increase the distance between positive and negative values, which aided in the interpretation of the results. This also permitted visual distinction between positive sera and negative or weakly reactive sera. The assay was effective using either blood or serum as the source of primary antibody. A further advantage of protein A over anti-Ig conjugate was its ability to detect specific antibody in dog as well as human sera. Finally, we demonstrated the usefulness of the protein A ELISA with a recombinant leishmania antigen, gp63.

Colour Doppler flow mapping in the diagnosis of traumatic ventricular septal defect

The use of colour Doppler flow mapping allows noninvasive diagnosis and gives haemodynamic information on the severity of ventricular septal defects. We describe the case of a man with delayed presentation of a traumatic ventricular septal defect in whom colour Doppler flow mapping permitted conservative management after accurate noninvasive diagnosis.

Angiographic patency study of anistreplase versus streptokinase in acute myocardial infarction

128 patients with acute myocardial infarction of duration 6 h or less were randomised in double-blind fashion to receive 30 U anistreplase over 5 min or 1.5 MU streptokinase over 1 h, both intravenously. Angiographic patency was assessed 90 min and 24 h from the start of therapy. 55% of patients who received anistreplase and 53% of patients who received streptokinase had patent infarct-related arteries (TIMI grade 2-3) at 90 min (95% CI 42-68% and 40-66%, respectively). At 24 h 81% and 87.5% of arteries were patent respectively (95% CI, 71-91% and 83.5-91.5%). Time to therapy had no significant effect on patency rates. There was one early reocclusion within 24 h in each treatment group and clinical evidence of reocclusion was recorded between 24 h and hospital discharge in a further 5 patients (streptokinase 3, anistreplase 2). With these regimens, therefore, anistreplase and streptokinase gave the same patency rates.

Testosterone, cortisol, and creatine kinase levels in male distance runners during reduced training

The purpose of this study was to examine if reduced training would reestablish normal testosterone, cortisol, and creatine kinase (CK) levels in male distance runners. Ten male runners (mean +/- SE) age 32.0 +/- 2.6 yrs, body fat 9.6 +/- 1.0%, VO2max 61.8 +/- 1.1 ml/kg/min) were monitored during 4 weeks of normal training (baseline training, BT) and 3 weeks of reduced training (RT). During BT running distance averaged 81 +/- 5 km/week, 6 days/week. During RT the runners reduced weekly training volume by 70% of BT to 24 +/- 2 km/week and training frequency to 5 days/week. Weekly resting blood samples were obtained between 0600-0900 hrs after an overnight fast. During BT resting total testosterone levels averaged 5.10 +/- 0.21 ng/ml, which is within the low ranges previously reported in male distance runners. Testosterone levels were not affected by RT (avg of 5.38 +/- 0.31 ng/ml). Cortisol levels were in the high range of normal during BT (23.61 +/- 1.18 ug/dl) and were not altered with RT (avg of 23.14 +/- 1.56 ug/dl). Creatine kinase was elevated (168 +/- 15 U/L) during BT and was significantly reduced (P less than 0.001) at weeks 1-3 of RT (avg of 99 +/- 9 U/L). These results suggest that normally training male runners have low resting total testosterone levels and cortisol levels in the high-normal range. Resting testosterone and cortisol were not responsive to the training reduction. Creatine kinase appears to be sensitive to relative changes in training.

A protective monoclonal antibody recognizes an epitope in the carboxyl-terminal cysteine-rich domain in the precursor of the major merozoite surface antigen of the rodent malarial parasite, Plasmodium yoelii

The 195-kDa major merozoite surface antigen of Plasmodium falciparum (Pf PMMSA) is a potential candidate for the development of a blood-stage malarial vaccine. We have focused on an analogous 230-kDa Ag of the rodent malarial parasite, Plasmodium yoelii, in an effort to study this protein in an experimental model system. Previously we reported the cloning and sequencing of a 2.1-kb portion of the gene encoding the carboxyl-terminal 77 kDa of the Py PMMSA. This region contained the B cell epitope recognized by mAb 302, a mAb shown to protect mice passively against P. yoelii challenge infection. To localize this B cell epitope, we have inserted various restriction fragments of the cloned Py PMMSA sequence into the bacterial expression vector pMG27NSTerm. Recombinant peptides of 74, 40, 34, 17, and 10 kDa have been produced which bear the epitope recognized by mAb 302. The results demonstrate that this B cell epitope is located within the most carboxyl-region of the Py PMMSA which contains a series of ten cysteine residues, also found in the PMMSA of P. falciparum. Further analysis showed that the reduction of disulfide bonds as well as the deletion of CYS-607 of the cloned sequence, resulted in the loss of the expression of this epitope. It is of interest that this epitope does not appear to be a dominant B cell determinant of the Py PMMSA molecule during infection. Inasmuch as this cysteine-rich domain of Py PMMSA displays considerable homology with that of Pf PMMSA, our data suggest that this region of the Pf PMMSA should be considered for inclusion in the development of a blood-stage vaccine.

A protective monoclonal antibody recognizes an epitope in the carboxyl-terminal cysteine-rich domain in the precursor of the major merozoite surface antigen of the rodent malarial parasite, Plasmodium yoelii

The 195-kDa major merozoite surface antigen of Plasmodium falciparum (Pf PMMSA) is a potential candidate for the development of a blood-stage malarial vaccine. We have focused on an analogous 230-kDa Ag of the rodent malarial parasite, Plasmodium yoelii, in an effort to study this protein in an experimental model system. Previously we reported the cloning and sequencing of a 2.1-kb portion of the gene encoding the carboxyl-terminal 77 kDa of the Py PMMSA. This region contained the B cell epitope recognized by mAb 302, a mAb shown to protect mice passively against P. yoelii challenge infection. To localize this B cell epitope, we have inserted various restriction fragments of the cloned Py PMMSA sequence into the bacterial expression vector pMG27NSTerm. Recombinant peptides of 74, 40, 34, 17, and 10 kDa have been produced which bear the epitope recognized by mAb 302. The results demonstrate that this B cell epitope is located within the most carboxyl-region of the Py PMMSA which contains a series of ten cysteine residues, also found in the PMMSA of P. falciparum. Further analysis showed that the reduction of disulfide bonds as well as the deletion of CYS-607 of the cloned sequence, resulted in the loss of the expression of this epitope. It is of interest that this epitope does not appear to be a dominant B cell determinant of the Py PMMSA molecule during infection. Inasmuch as this cysteine-rich domain of Py PMMSA displays considerable homology with that of Pf PMMSA, our data suggest that this region of the Pf PMMSA should be considered for inclusion in the development of a blood-stage vaccine.