Effect of probiotic on innate inflammatory response and viral shedding in experimental rhinovirus infection - a randomised controlled trial

Ingestion of probiotics appears to have modest effects on the incidence of viral respiratory infection. The mechanism of these effects is not clear; however, there is evidence from animal models that the probiotic may have an effect on innate immune responses to pathogens. The purpose of this randomised, placebo-controlled study was to determine the effect of administration of Bifidobacterium animalis subspecies lactis Bl-04 on innate and adaptive host responses to experimental rhinovirus challenge. The effect on the response of chemokine (C-X-C motif) ligand 8 (CXCL8) to rhinovirus infection was defined as the primary endpoint for the study. 152 seronegative volunteers who had been supplemented for 28 days, 73 with probiotic and 79 with placebo, were challenged with RV-A39. Supplement or placebo administration was then continued for five days during collection of specimens for assessment of host response, infection, and symptoms. 58 probiotic and 57 placebo-supplemented volunteers met protocol-defined criteria for analysis. Probiotic resulted in higher nasal lavage CXCL8 on day 0 prior to virus challenge (90 vs 58 pg/ml, respectively, P=0.04, ANCOVA). The CXCL8 response to rhinovirus infection in nasal lavage was significantly reduced in the probiotic treated group (P=0.03, ANCOVA). Probiotic was also associated with a reduction in nasal lavage virus titre and the proportion of subjects shedding virus in nasal secretions (76% in the probiotic group, 91% in the placebo group, P=0.04, Fisher Exact test). The administration of probiotic did not influence lower respiratory inflammation (assessed by exhaled nitric oxide), subjective symptom scores, or infection rate. This study demonstrates that ingestion of Bl-04 may have an effect on the baseline state of innate immunity in the nose and on the subsequent response of the human host to rhinovirus infection. Clinicaltrials.gov registry number: NCT01669603.

Effect of a novel penetration enhancer on the ungual permeation of two antifungal agents

OBJECTIVES

The aim of this study was to demonstrate the effect of a novel permeation enhancer system using two existing marketed nail lacquers and the delivery of terbinafine through human nail samples in vitro.

METHODS

Initially a modified Franz cell was used, where sections of human nail serve as the barrier through which drug penetrates into an agar-filled chamber infected with dermatophytes. A second study was performed using a novel infected nail model where dermatophytes are incubated with and grow into human nail and ATP levels are used as biological marker for antimicrobial activity.

KEY FINDINGS

The novel permeation enhancing system increased the permeation of both existing drugs formulated in nail lacquers and terbinafine through human nail sections mounted in a modified Franz cell. Furthermore the ATP assay confirmed that the system also enhanced the permeation of terbinafine through infected cadaver nail resulting in a decrease in ATP levels equivalent to those of uninfected negative control samples.

CONCLUSIONS

This study has clearly demonstrated that the use of a novel permeation enhancing system, which fundamentally alters the chemical structure of the nail, not only enhances the efficacy of the existing topical formulations but also enables the delivery and efficacy of terbinafine when applied ungually. Such a topically applied system has the possibility of overcoming the systemic side effects when terbinafine is delivered orally.

Overcoming the nail barrier: A systematic investigation of ungual chemical penetration enhancement

This study investigated the in vitro nail permeability of penetrants of varying lipophilicity-caffeine (CF, logP -0.07), methylparaben (MP, logP 1.96) and terbinafine (TBF, logP 3.3) and the effect of 2 novel penetration enhancers (PEs), thioglycolic acid (TA) and urea hydrogen peroxide (urea H(2)O(2)) on their permeation. Studies were conducted using full thickness human nail clippings and ChubTur((R)) diffusion cells and penetrants were applied as saturated solutions. The rank order of steady-state penetrant flux through nails without PE application (MP>CF>TBF) suggested a greater sensitivity to penetrant molecular weight rather than logP. TA increased the flux of CF and MP approximately 4- and approximately 2-fold, respectively, whilst urea H(2)O(2) proved ineffective at enhancing permeability. The sequential application of TA followed by urea H(2)O(2) increased TBF and CF flux ( approximately 19- and approximately 4-fold, respectively) but reversing the application order of the PEs was only mildly effective at increasing just MP flux ( approximately 2-fold). Both nail PEs are likely to function via disruption of keratin disulphide bonds and the associated formation of pores that provide more 'open' drug transport channels. Effects of the PEs were penetrant specific, but the use of a reducing agent (TA) followed by an oxidising agent (urea H(2)O(2)) dramatically improved human nail penetration.

Nail swelling as a pre-formulation screen for the selection and optimisation of ungual penetration enhancers

INTRODUCTION

Targeting drug treatment to fungal infections that reside within or below the nail plate is problematic due to the highly restrictive barrier of the human nail. To optimise topical formulations for ungual drug delivery, inclusion of an effective penetration enhancer (PE) is imperative. At present, in vitro nail permeation studies can take weeks or months in order to obtain any meaningful data because the lack of a simple in vitro model to identify and develop nail PEs makes the selection and optimisation of novel PEs an empirical and inefficient process. The aim of this study was to compare three methods for pre-formulation screening of putative ungual PEs and then to select the most suitable technique for screening candidates that may enhance the permeation of therapeutic agents through the human nail.

METHODS

Three screening techniques were evaluated; nail swelling (weight increase of human nail clippings), horse hoof swelling (weight increase of horse hoof clippings) and nail penetration of a radiolabelled permeability probe. Four test PEs were evaluated using each screening method and nail swelling was identified as a simple, rapid, economic, relevant and reliable technique. This screen was then used to evaluate 20 potential PEs. Thioglycolic acid (TA), hydrogen peroxide (H(2)O(2)) and urea H(2)O(2) produced the greatest nail weight increases; 71.0+/-4.6%, 69.2+/-6.6%, and 69.0+/-9.9 respectively. To confirm the relationship between human nail swelling and altered ungual barrier function, a permeation study was performed in human nails using caffeine as a model penetrant.

RESULTS AND DISCUSSION

Human nails pre-treated with TA in vitro had a 3.8-fold increase in caffeine flux compared to the control (TA-free solution). This study illustrated the potential to use human nail clipping swelling as a surrogate marker of PE activity for topical ungual drug delivery.

Ineffectiveness of intranasal zinc gluconate for prevention of experimental rhinovirus colds

Zinc has generally been administered by the oral route in studies of prevention or treatment of the common cold. The purpose of these studies was to evaluate the effectiveness of intranasal zinc gluconate for prevention of experimental rhinovirus infection and illness. Ninety-one volunteers, 41 treated with active medication and 50 treated with placebo, received study medication for 3 days, were inoculated with rhinovirus, and then were treated with study medication for an additional 6 days. Rhinovirus infection was documented in 37 (74%) of the 50 placebo-treated volunteers and in 32 (78%) of the 41 volunteers treated with active medication. Zinc treatment had no effect on total symptom score, rhinorrhea, nasal obstruction, or the proportion of infected volunteers who developed clinical colds. These data do not support a role for intranasal zinc gluconate for prevention or treatment of the common cold.

Assessment of adherence with medications in human immunodeficiency virus-infected children

The purpose of this study was to determine the reliability of screening for medication adherence in HIV-infected children. The results suggest that caregivers who are unable to describe the medication regimen or who are nonadherent with appointments are unlikely to adhere to the medication regimen. Adherence with at least 90% of medication doses was associated with a virologic response.

Fluconazole for prophylaxis against candidal rectal colonization in the very low birth weight infant

BACKGROUND

Candidal infections are an important cause of morbidity and mortality in the very low birth weight (VLBW) infant. Current intervention focuses on treatment once candidal septicemia is either suspected or diagnosed. Studies have suggested that colonization with candidal species is an important risk factor for subsequent infection.

OBJECTIVE

To determine whether prophylactic fluconazole for the first 28 days of life results in a decreased incidence of candidal colonization in the VLBW infant.

RESEARCH DESIGN

Prospective, randomized, controlled, intention-to-treat design comparing prophylaxis with fluconazole versus placebo for the first 28 days of life.

SETTING

A tertiary level intensive care nursery in a major teaching hospital in Charleston, South Carolina.

PATIENTS

One hundred three infants with a birth weight of <1500 g, either inborn or outborn, who were admitted to the intensive care nursery between January 1998 and February 1999.

METHODS

Infants were enrolled within 72 hours of life with rectal cultures performed on the day of randomization (DOR), as well as day of life (DOL) 7, 14, and 28. Those infants with a birth weight of <1250 g had additional cultures on DOL 35, 49, and 56. Cultures were plated on selective media for isolation of candidal organisms. Infants were randomized to receive either fluconazole (6 mg/kg) or placebo on the DOR. Subsequent doses were given every 72 hours until DOL 7 and then every 24 hours until DOL 28. Medication was given either intravenously or by feeding tube once the infant had been gavage feeding for a 48-hour period without feeding intolerance. Aspartate aminotransferase and alanine aminotransferase levels were obtained on DOR and DOL 7, 14, and 28 to assess for fluconazole toxicity. The minimal inhibitory concentration to fluconazole was determined for all positive cultures to assess the development of resistance.

RESULTS

The infants who received fluconazole (n = 53) and placebo (n = 50) had no statistical difference in the major risk factors known to increase the chances of candidal septicemia in the VLBW infant. Rectal colonization by candidal species was detected in 8 of the 53 fluconazole-treated patients (15.1%) and in 23 of the 50 infants treated with placebo (46%). Fluconazole significantly reduced rectal colonization from DOL 14 through DOL 56 in all infants with a birth weight of <1250 g, and from DOL 14 through DOL 56 in all infants with a birth weight of 1250 to 1500 g. Alanine aminotransferase levels were higher in the fluconazole versus the placebo-treated group on DOL 14 (18.1 IU/L vs 15 IU/L), but no clinically significant abnormalities were observed. Candida albicans was the most common species isolated. There was no increase in species of Candida noted for their intrinsic resistance to fluconazole, and there was no statistically significant difference in the minimal inhibitory concentrations to fluconazole for all C albicans isolates in either group at any period.

CONCLUSION

Prophylactic administration of fluconazole to the VLBW infant for the first 28 days of life is safe and results in a decreased risk of rectal colonization by candidal species. Larger studies to determine the effect of prophylaxis on candidal septicemia and development of resistance in such a selective high-risk group are warranted before initiation of routine prophylaxis.fluconazole, very low birth weight infant, prophylaxis, candidal sepsis, sensitivities to fluconazole.

The treatment of rhinovirus infections: progress and potential

The common cold is an important illness both as a result of the economic impact of this common disease and because of the morbidity associated with the complications of the illness. Recent attempts to develop antiviral treatments for the common cold represent a substantial advance over previous efforts. Formidable barriers remain to be overcome, however, before any of these new products will be proven to be clinically useful. Recent advances in our understanding of the pathogenesis of common cold symptoms have provided insights into potential new targets for the treatment of this illness.

Leucine 42 in the fibronectin motif of streptokinase plays a critical role in fibrin-independent plasminogen activation

The NH(2) terminus (residues 1-59) of streptokinase (SK) is a molecular switch that permits fibrin-independent plasminogen activation. Targeted mutations were made in recombinant (r) SK1-59 to identify structural interactions required for this process. Mutagenesis established the functional roles of Phe-37and Glu-39, which were projected to interact with microplasmin in the activator complex. Mutation of Leu-42 (rSK1-59(L42A)), a conserved residue in the SK fibronectin motif that lacks interactions with microplasmin, strongly reduced plasminogen activation (k(cat) decreased 50-fold) but not amidolysis (k(cat) decreased 1.5-fold). Otherwise rSK1-59(L42A) and native rSK1-59 were indistinguishable in several parameters. Both displayed saturable and specific binding to Glu-plasminogen or the remaining SK fragment (rSKDelta59). Similarly rSK1-59 and rSK1-59(L42A) bound simultaneously to two different plasminogen molecules, indicating that both plasminogen binding sites were intact. However, when bound to SKDelta59, rSK1-59(L42A) was less effective than rSK1-59 in restructuring the native conformation of the SK A domain, as detected by conformation-dependent monoclonal antibodies. In the light of previous studies, these data provide evidence that SK1-59 contributes to fibrin-independent plasminogen activation through 1) intermolecular interactions with the plasmin in the activator complex, 2) binding interactions with the plasminogen substrate, and 3) intramolecular interactions that structure the A domain of SK for Pg substrate processing.

Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds

Two clinical trials were conducted, one involving 273 subjects with experimental rhinovirus colds and the other involving 281 subjects with natural colds. Symptomatic volunteers were randomized to receive oral lozenges containing zinc gluconate (13.3 mg), zinc acetate (5 or 11.5 mg), or placebo. The median duration of illness in zinc gluconate recipients was 2.5 days, contrasted with 3.5 days in the placebo recipients (P=.035), in the experimental colds study. Zinc gluconate had no effect on symptom severity and zinc acetate had no effect on either duration or severity. Neither formulation had an effect on the duration or severity of natural cold symptoms. Evaluation of blinding, taste, and adverse events revealed no significant differences among the 4 treatment arms. Zinc compounds appear to have little utility for common-cold treatment.

Effectiveness of pseudoephedrine plus acetaminophen for treatment of symptoms attributed to the paranasal sinuses associated with the common cold

BACKGROUND

Little data exist on the cause and treatment of subfacial pain and pressure and other discomfort attributed to the paranasal sinuses that develop early during the course of the common cold. The purpose of this study was to determine the efficacy of the combination of pseudoephedrine hydrochloride with acetaminophen for the treatment of early symptoms during colds, which are attributed by the patient to the sinuses.

METHODS

Four hundred thirty subjects (216, pseudoephedrine and acetaminophen recipients; 214, placebo recipients) with cold symptoms of 48 hours or less who reported overall "sinus" symptoms of at least moderate severity were enrolled in this randomized double-blind placebo-controlled 2-dose study. Self-reported symptoms were scored (0 to 4, absent to severe) before and at 2 hours after the first and second doses. The 2 primary were measured 2 hours after the second dose were the overall sinus symptom assessment and a weighted composite assessment of sinus pressure, pain, and congestion (sinus symptoms).

RESULTS

Compared with baseline, 2 hours after the second dose, the mean +/- SEM overall sinus symptom assessment score had decreased by 1.30 +/- 0. 06 in the pseudoephedrine and acetaminophen-treated subjects compared with 0.93 +/- 0.06 in the placebo-treated subjects (P< or = .029). The mean +/- SEM weighted average of sinus symptoms 2 hours after the second dose of study medication had decreased by 1.14 +/- 0.06 in the pseudoephedrine and acetaminophen-treated subjects compared with 0.84 +/- 0.06 in the placebo-treated subjects (P< or = .029). Reductions in similar magnitude were also observed for each of the individual sinus symptoms, and headache and rhinorrhea. Nervousness occurred in 4% of the pseudoephedrine and acetaminophen recipients compared with 0% of placebo recipients (P =.007).

CONCLUSION

Our results suggest that pseudoephedrine plus acetaminophen is effective for relief of symptoms attributable to the paranasal sinuses that may develop early in the course of a cold. Arch Fam Med. 2000;9:979-985

NMR structure of the HIV-1 nucleocapsid protein bound to stem-loop SL2 of the psi-RNA packaging signal. Implications for genome recognition

The RNA genome of the human immunodeficiency virus type-1 (HIV-1) contains a approximately 120 nucleotide Psi-packaging signal that is recognized by the nucleocapsid (NC) domain of the Gag polyprotein during virus assembly. The Psi-site contains four stem-loops (SL1-SL4) that possess overlapping and possibly redundant functions. The present studies demonstrate that the 19 residue SL2 stem-loop binds NC with affinity (K(d)=110(+/-50) nM) similar to that observed for NC binding to SL3 (K(d)=170(+/-65) nM) and tighter than expected on the basis of earlier work, suggesting that NC-SL2 interactions probably play a direct role in the specific recognition and packaging of the full-length, unspliced genome. The structure of the NC-SL2 complex was determined by heteronuclear NMR methods using (15)N,(13)C-isotopically labeled NC protein and SL2 RNA. The N and C-terminal "zinc knuckles" (Cys-X(2)-Cys-X(4)-His-X(4)-Cys; X=variable amino acid) of HIV-1 NC bind to exposed guanosine bases G9 and G11, respectively, of the G8-G9-U10-G11 tetraloop, and residues Lys3-Lys11 of the N-terminal tail forms a 3(10) helix that packs against the proximal zinc knuckle and interacts with the RNA stem. These structural features are similar to those observed previously in the NMR structure of NC bound to SL3. Other features of the complex are substantially different. In particular, the N-terminal zinc knuckle interacts with an A-U-A base triple platform in the minor groove of the SL2 RNA stem, but binds to the major groove of SL3. In addition, the relative orientations of the N and C-terminal zinc knuckles differ in the NC-SL2 and NC-SL3 complexes, and the side-chain of Phe6 makes minor groove hydrophobic contacts with G11 in the NC-SL2 complex but does not interact with RNA in the NC-SL3 complex. Finally, the N-terminal helix of NC interacts with the phosphodiester backbone of the SL2 RNA stem mainly via electrostatic interactions, but does not bind in the major groove or make specific H-bonding contacts as observed in the NC-SL3 structure. These findings demonstrate that NC binds in an adaptive manner to SL2 and SL3 via different subsets of inter and intra-molecular interactions, and support a genome recognition/packaging mechanism that involves interactions of two or more NC domains of assembling HIV-1 Gag molecules with multiple Psi-site stem-loop packaging elements during the early stages of retrovirus assembly.

A mechanism for plus-strand transfer enhancement by the HIV-1 nucleocapsid protein during reverse transcription

The HIV-1 nucleocapsid protein (NC) functions as a nucleic acid chaperone during the plus-strand transfer step in reverse transcription by facilitating annealing of the primer binding site (PBS) sequence in the short plus-strand strong-stop DNA fragment [(+) SSDNA] to a complementary site located near the 3' end of the minus-strand DNA [(-) PBS DNA]. To investigate the mechanism by which NC performs this function, we have prepared an 18-nucleotide (-) PBS DNA for nuclear magnetic resonance (NMR) based structural and NC binding studies. The (-) PBS DNA forms a stable hairpin (T(m) approximately 42 +/- 5 degrees C) that contains a five-residue loop and a bulged thymine in a guanosine-cytosine-rich stem. Addition of substoichiometric amounts of NC results in significant broadening and reductions in NMR signal intensities of the Watson-Crick base-paired imino protons and a reduction by 20 degrees C in the upper temperature at which the imino proton signals are detectable, consistent with destabilization of the structure. The results suggest that inefficient annealing in the absence of NC may be due to the intrinsic stability of an internal (-) PBS DNA hairpin and that NC facilitates strand transfer by destabilizing the hairpin and exposing stem nucleotides for base pairing with the PBS sequence in (+) SSDNA.

Protein-RNA recognition

The x-ray structure of the glutamine aminoacyl tRNA synthetase bound to its cognate tRNA(Gln) and ATP was reported by Steitz and co-workers in 1989, providing the first high resolution structure of a protein-RNA complex. Since then, high resolution structures have been reported for RNA complexes with five other tRNA synthetases, the elongation factor Tu, the bacteriophage MS2 coat protein, the human spliceosomal U1A and U2B"-U1A' proteins, and the HIV-1 nucleocapsid protein. Although the number of high resolution structures of protein-RNA complexes are rather small, some general themes have begun to emerge regarding the nature and mechanisms of protein-RNA recognition.

Ineffectiveness of echinacea for prevention of experimental rhinovirus colds

The purpose of this study was to assess the effectiveness of echinacea for the prevention of experimental rhinovirus colds. Infection occurred in 44 and 57% and illness occurred in 36 and 43% of the echinacea- and placebo-treated subjects, respectively. This preparation of echinacea had no significant effect on either the occurrence of infection or the severity of illness.

NMR structure of stem-loop SL2 of the HIV-1 psi RNA packaging signal reveals a novel A-U-A base-triple platform

The genome of the human immunodeficiency virus type-1 (HIV-1) contains a stretch of approximately 120 nucleotides known as the psi-site that is essential for RNA packaging during virus assembly. These nucleotides have been proposed to form four stem-loops (SL1-SL4) that have both independent and overlapping functions. Stem-loop SL2 is important for efficient recognition and packaging of the full-length, unspliced viral genome, and also contains the major splice-donor site (SD) for mRNA splicing. We have determined the structure of the 19-residue SL2 oligoribonucleotide by heteronuclear NMR methods. The structure is generally consistent with the most recent of two earlier secondary structure predictions, with residues G1-G2-C3-G4 and C6-U7 forming standard Watson Crick base-pairs with self-complementary residues C16-G17-C18-C19 and A12-G13, respectively. However, residue A15, which is located near the center of the stem, does not form a predicted bulge, and residues A5 and U14 do not form an expected Watson-Crick base-pair. Instead, these residues form a novel A5-U14-A15 base-triple that appears to be stabilized by hydrogen bonds from A15-H61 and -H62 to A5-N1 and U14-O2, respectively; from A5-H61 to U14-O2, and from C16-H42 to U14-O2'. A kink in the backbone allows the aromatic rings of the sequential U14-A15 residues to be approximately co-planar, adopting a stable "platform motif" that is structurally similar to the A-A (adenosine) platforms observed in the P4-P6 ribozyme domain of the Tetrahymena group I intron. Platform motifs generally function in RNA by mediating long-range interactions, and it is therefore possible that the A-U-A base-triple platform mediates long-range interactions that either stabilize the psi-RNA or facilitate splicing and/or packaging. Residue G8 of the G8-G9-U10-G11 tetraloop is stacked above the U7-A12 base-pair, and the remaining tetraloop residues are disordered and available for potential interactions with either other RNA or protein components.

Effects of an experimentally induced rhinovirus cold on sleep, performance, and daytime alertness

STUDY OBJECTIVES

There is accumulating evidence that the common cold produces impairments in psychomotor vigilance. This has led some investigators to hypothesize that such illnesses may also have disruptive effects on sleep. While several self-report studies suggest that viral illness may influence sleep parameters, no studies have assessed polysomnographically recorded sleep following viral infections.

DESIGN

Parallel control group comparison.

SETTING

Sleep laboratory in a large urban medical center.

PARTICIPANTS

Twenty-one men and women with susceptibility to the rhinovirus type 23.

INTERVENTIONS

Nasal inoculation with rhinovirus type 23.

MEASUREMENTS

Polysomnographically recorded sleep for five nights (2300-0700 h) post-viral inoculation. Twice daily (1030 and 1430 h) performance assessment during each experimental day using auditory vigilance and divided attention tasks. A multiple sleep latency test (MSLT) was performed daily for the duration of the study.

RESULTS

In symptomatic individuals, total sleep time decreased an average of 23 min, consolidated sleep decreased an average of 36 min, and sleep efficiency was reduced by an average of 5% during the active viral period (experimental days/nights 3-5) compared with the incubation period. Psychomotor performance was impaired. These changes were significantly greater than those observed in asymptomatic individuals.

CONCLUSIONS

The common cold can have detrimental effects on sleep and psychomotor performance in symptomatic individuals during the initial active phase of the illness.

Efficacy of tremacamra, a soluble intercellular adhesion molecule 1, for experimental rhinovirus infection: a randomized clinical trial

CONTEXT

Attachment of most rhinovirus subtypes to cells depends on a cellular receptor, the intercellular adhesion molecule 1 (ICAM-1). A recombinant soluble ICAM-1 (tremacamra, formerly BIRR 4) has shown possible efficacy in early studies.

OBJECTIVE

To determine the efficacy and safety of intranasal administration of tremacamra in experimental rhinovirus colds in humans.

DESIGN

Four randomized, double-blind, placebo-controlled trials conducted in January to March 1996.

SETTING AND SUBJECTS

Volunteers between the ages of 18 and 60 years who had an antibody titer of 1:4 or less to the challenge virus. Subjects were isolated in a hotel room during study days 0 to 8; symptoms were recorded through day 14. A total of 198 subjects were randomized, of whom 196 received drug or placebo and were included in the safety analysis. A total of 177 subjects were included in the efficacy analysis.

INTERVENTIONS

Tremacamra or placebo was given beginning 7 hours before inoculation with rhinovirus type 39 (preinoculation studies) or 12 hours after (postinoculation studies). Tremacamra as an inhaled solution or as a powder (each given preinoculation and postinoculation for a total of 4 studies) and placebo were given in 6 doses at 3-hour intervals daily during days 1 through 7. Recipients of active treatment received 367 microg of tremacamra per nostril per dose for a total of 4.4 mg/d.

MAIN OUTCOME MEASURES

Effect of tremacamra on infection, as determined by virus isolation and seroconversion, and on illness, as determined by symptom scores, clinical colds, and nasal mucus weights. Treatment-by-study interaction was not significant, so results were pooled for the main analysis.

RESULTS

A total of 88 (92%) of the 96 subjects in the placebo groups and 69 (85%) of the 81 subjects in the active treatment groups were infected (P=.19). For placebo vs tremacamra, respectively, the total symptom score (+/- 95% confidence interval [CI]) was 17.6 (+/- 2.7) vs 9.6 (+/- 2.9), the proportion of clinical colds was 64/96 (67% +/- 9%) vs 36/81 (44% +/- 11%), and the nasal mucus weight was 32.9 (+/- 8.8) g vs 14.5 (+/- 9.4) g (P<.001 for all comparisons). Tremacamra was not associated with adverse effects or evidence of absorption through the nasal mucosa and did not interfere with development of neutralizing antibody.

CONCLUSION

Tremacamra reduced the severity of experimental rhinovirus colds. Whether tremacamra will be useful clinically will require further study.

Effect of nitric oxide on rhinovirus replication and virus-induced interleukin-8 elaboration

Nitric oxide (NO) has been reported to have disparate effects in different viral infections. We conducted a study to determine whether rhinovirus (RV) infection is associated with production of NO, and to assess the effect of NO on RV-induced interleukin-8 (IL-8) elaboration both in vitro in monolayers of BEAS-2B cells, an immortalized respiratory epithelial cell line, and in MRC-5 cells, a diploid human embryonic lung fibroblast cell line, challenged with purified RV type 39, as well as in vivo, in experimental infections with RV type 23. Virus replication was not affected by pretreatment of cell monolayers with any of three different NO donors, and RV infection did not stimulate production of NO. Pretreatment of cell monolayers with either NO donors or inhibitors of NO synthase had no effect on RV-induced IL-8 elaboration measured either 6 or 24 h after virus challenge. Nasal wash specimens from RV-infected volunteers contained low concentrations of nitrite that were not different from the concentrations in specimens from sham-challenged subjects. The concentration of nitrite in these specimens did not change over the course of the subjects' rhinoviral illness. These results suggest that NO does not participate in the pathogenesis of RV infections.

The role of oxidative stress in rhinovirus induced elaboration of IL-8 by respiratory epithelial cells

A direct correlation has been reported between the severity of symptoms associated with rhinovirus infection and the concentration of interleukin-8 in nasal secretions. The purpose of these studies was to examine the mechanism of rhinovirus-induced IL-8 elaboration. Rhinovirus infection induced oxidative stress in Beas-2b cells and the concentration of H2O2 in supernatant media from rhinovirus challenged cells was 12.5 +/- 6.1 microM 1 h after challenge compared to 0.7 +/- 0.3 microM in supernatant from control cells. N-acetyl cysteine inhibited RV-induced NF-kappaB activation and IL-8 elaboration. IL-8 concentrations were 36 +/- 2 pg/ml and 10 +/- 1 pg/ml 6 h after virus challenge in untreated and NAC-treated (30 mM NAC) cells, respectively. Despite the effects of NAC on IL-8 elaboration and NF-kappaB activation, RV stimulated increases in supernatant H2O2 were not altered by NAC. These data suggest that RV stimulation of IL-8 in respiratory epithelium is mediated through production of oxidative species and the subsequent activation of NF-kappaB.

Solution structure of a zinc domain conserved in yeast copper-regulated transcription factors

The three dimensional structure of the N-terminal domain (residues 1-42) of the copper-responsive transcription factor Amtl from Candida glabrata has been determined by two-dimensional 1H-correlated nuclear magnetic resonance (NMR) methods. The domain contains an array of zinc-binding residues (Cys-X2-Cys-X8-Cys-X-His) that is conserved among a family of Cu-responsive transcription factors. The structure is unlike those of previously characterized zinc finger motifs, and consists of a three-stranded antiparallel beta-sheet with two short helical segments that project from one end of the beta-sheet. Conserved residues at positions 16, 18 and 19 form a basic patch that may be important for DNA binding.

Association between interleukin-8 concentration in nasal secretions and severity of symptoms of experimental rhinovirus colds

The purpose of this study was to examine the association between experimental rhinovirus infection and the elaboration of interleukin-8 (IL-8) into nasal secretions of volunteers and to determine the effect of pentoxifylline on IL-8 elaboration and rhinovirus-associated common cold symptoms. Fifty-four subjects with experimental rhinovirus infections and 20 sham-inoculated subjects were studied. Pentoxifylline had no effect on rhinovirus-induced symptoms or nasal-secretion IL-8 concentrations. IL-8 concentrations were significantly greater in nasal secretions from infected symptomatic subjects than in those from infected asymptomatic or sham-challenged subjects on days 2-4 after virus challenge. In infected subjects, there was significant rank correlation between nasal obstruction severity, rhinorrhea severity, and nasal-wash albumin concentrations and the change in IL-8 concentration from baseline on days 2-4 after virus challenge.

Effectiveness of clemastine fumarate for treatment of rhinorrhea and sneezing associated with the common cold

Limited data support the use of first-generation antihistamines for treatment of the common cold. The purpose of this study was to test the effectiveness of clemastine fumarate, a first-generation antihistamine, for treatment of sneezing and rhinorrhea associated with naturally occurring common colds. Four hundred three subjects (202 clemastine fumarate recipients and 201 placebo recipients) who reported new onset (< 24 hours) of cold symptoms that included rhinorrhea or sneezing were studied. At baseline (day 1), the mean symptom-severity scores +/- SEM for the clemastine fumarate and placebo groups were not significantly different. The mean rhinorrhea-severity score +/- SEM was not different on day 2; however, on day 3, the mean rhinorrhea-severity score +/- SEM was 1.02 +/- 0.07 for the clemastine fumarate group and 1.39 +/- 0.07 for the placebo group (P < .001). This treatment effect persisted on day 4. A significant effect on sneezing was noted on days 2-4. Sedation occurred in 14% of the clemastine fumarate-treated subjects and 1.5% of the placebo-treated subjects (P < .0001).

Epidemiology, pathogenesis, and treatment of the common cold

OBJECTIVE

Reading this article will reinforce the reader's knowledge of the pathogenesis of the common cold. The rationale for current and potential therapies for the common cold are reviewed in the context of current concepts of the pathogenesis of these illnesses.

DATA SOURCES AND STUDY SELECTION

A MEDLINE literature search was done using the search terms common cold, rhinovirus, and viral respiratory infection. The search was restricted to the English language. Articles were selected for review if the title and/or abstract suggested the content was relevant to the subject of this review. The bibliographies of selected articles were used as a source of additional literature.

RESULTS

Recent studies suggest that the host response to the virus is an important contributor to the pathogenesis of the common cold. Inflammatory mediators, especially the pro-inflammatory cytokines, appear to be an important component of this response and present an attractive target for new interventions for common cold therapies. Currently available treatments for the common cold have limited efficacy against specific symptoms. These therapies should be selected to treat the specific symptoms that are perceived to be the most bothersome by the patient.

Effect of topical adrenergic decongestants on middle ear pressure in infants with common colds

BACKGROUND

Otitis media is frequently a complication of the common cold. Obstruction of the eustachian tube ostia by nasopharyngeal edema has been suggested as a cause of this complication.

OBJECTIVE

To determine the effect of a topical adrenergic decongestant on middle ear pressure in infants with common cold symptoms.

METHODS

The study was conducted with a randomized, double blinded, placebo-controlled design. Middle ear pressure was determined in infants 6 to 18 months old who had common cold symptoms. Infants with abnormal middle ear pressure (< or = -100 mm H2O) in either ear were treated with intranasal phenylephrine drops or placebo. The effect of the treatment on middle ear pressure in ears with abnormal pressure at baseline was determined 1 h later.

RESULTS

Twenty-three of 44 infants with abnormal middle ear pressures received intranasal phenylephrine drops and 21 received placebo. Middle ear pressure remained abnormal after treatment with phenylephrine in 29 of 33 (88%) ears and after treatment with placebo in 26 of 34 (76%). The mean change in middle ear pressure after treatment was +23 mm H2O in the active group and +40 mm H2O in the placebo group.

CONCLUSIONS

Treatment of nasal obstruction with topical adrenergic decongestants does not improve abnormal middle ear pressures during the common cold.

Randomized controlled trial of clemastine fumarate for treatment of experimental rhinovirus colds

We used a rhinovirus challenge model to test the therapeutic efficacy of clemastine fumarate for reducing sneezing and nasal secretion in a double-blind, randomized clinical trial. Clemastine fumarate (1.34 mg) or placebo was administered at 8 A.M. and 8 P.M. for 4 days, beginning 24 hours, 36 hours, 48 hours, and 60 hours after viral challenge. Infected evaluable subjects who received clemastine (n = 75) had reduced sneeze-severity scores compared with those who received placebo (n = 75) on illness days 2 (0.3 vs. 0.5; P = .003), 3 (0.4 vs. 0.8; P = .0003), 4 (0.3 vs. 0.5; P = .025), and 5 (0.1 vs. 0.3; P = .03); sneeze counts for infected evaluable subjects (vs. counts for those who received placebo) were reduced on illness days 2 (1.5 vs. 3.1; P = .01), 3 (1.7 vs. 5.6; P = .0001), and 5 (0.7 vs. 1.9; P = .03). Infected evaluable subjects who received treatment had reduced rhinorrhea scores (compared with those who received placebo) on illness days 2 (0.7 vs. 1.0; P = .04) and 3 (0.6 vs. 0.9; P = .04) and had reduced nasal secretion weights on day 3 (3.6 g vs. 6.3 g; P = .03). Over 4 days of treatment, mean sneeze scores for infected evaluable subjects (vs. scores for those who received placebo) were reduced by 50%, mean sneeze counts by 57%, mean rhinorrhea scores by 27%, and mean nasal secretion weights by 35%. Other cold symptoms were unaffected by treatment. Treatment with clemastine was associated with an excess incidence of dry mouth (6%), dry nose (19%), and dry throat (17%).

Passive immunization for prevention of rotavirus illness in healthy infants

Infant formula supplemented with bovine antibody (BCIg) to human rotavirus has been reported to prevent or modify rotavirus infection and illness. The purpose of this field trial was to determine the safety and feasibility of passive immunization with bovine antibody for the prevention of rotavirus infection and illness in healthy infants. Sixty-four infants, 31 of whom received BCIg and 33 placebo, participated in the study. Rotavirus infection was detected in 11 (35%) and 14 (42%) infants in the 2 groups, respectively. Symptomatic rotavirus infection was documented in 1 (3%) of the infants receiving BCIg and in 6 (18%) of the infants who received the placebo (P > 0.05). The number of days with diarrhea/1000 days of observation was significantly less in the BCIg group, 4.2, than in the placebo group, 16.8 (P < 0.01). Similarly the number of days with rotavirus-associated diarrhea/1000 days was less in the BCIg group, 1.0, than in the placebo group, 13 (P < 0.01). This study establishes the feasibility of providing passive immunity for the prevention of rotavirus illness in healthy infants.

Historical cohort evaluation of ribavirin efficacy in respiratory syncytial virus infection

Evaluation of ribavirin therapy for respiratory syncytial virus infection of the lower respiratory tract is problematic because of multiple risk factors and variable severity of illness in respiratory syncytial virus-infected patients. To address these difficulties we used multivariate analysis and performed a historical concurrent cohort study in two children's hospitals one of which had used ribavirin since licensing and one that had not utilized ribavirin therapy. The medical records of 158 patients who satisfied the American Academy of Pediatrics inclusion criteria for receiving ribavirin were analyzed for three seasons (1988 to 1991). No significant benefit of ribavirin therapy could be appreciated for the whole group in length of stay (median, 5.0 vs. 6.5 days), days on oxygen therapy (median, 5 vs. 3), progression to ventilator status (3.8 vs. 3.9%) or mortality (1.9% vs. 1.9%) for ribavirin treatment vs. supportive care. Multivariate analysis failed to uncover a beneficial effect of ribavirin when all risk factors were considered. No significant differences were noted when ventilated and nonventilated patients were examined separately. Our data raise questions about the efficacy of ribavirin when used in common practice and suggest that further prospective study, with appropriate analysis, is needed to justify the continued widespread use of this drug.

Efficacy of oral WIN 54954 for prophylaxis of experimental rhinovirus infection

The efficacy of oral WIN 54954 for the prevention of rhinovirus infection and illness was tested in two randomized, double-blinded, placebo-controlled volunteer challenge studies. Volunteers were inoculated with rhinovirus type 39 (MIC of WIN 54954, 0.17 microgram/ml) or rhinovirus type 23 (MIC, 0.016 microgram/ml). The volunteers received two doses of drug (600 mg per dose) or placebo on the first day; this was followed by three doses on each of the subsequent 5 days. All volunteers were challenged with virus after the third dose of study drug. No significant antiviral or clinical effect was detected in either study. Pharmacokinetic studies revealed that on the last day of drug administration, 38 of 39 (97%) volunteers had trough levels of WIN 54954 in plasma greater than the MIC for the respective virus. Nasal wash specimens collected on the same day revealed a detectable level in only 6 of 24 (25%) volunteers at the peak (range, 6 to 24 ng/ml) and in only 2 of 14 (14%) volunteers at the trough (range, 6 and 7 ng/ml). These results suggest that the lack of efficacy of WIN 54954 against rhinovirus may be related to an inability to deliver sufficient drug to the site of viral infection.

The outcome of candiduria in pediatric patients

The presence of Candida in the urine of a seriously ill, pediatric patient presents a management problem because of a lack of information concerning the natural history of candiduria and its relationship to disseminated candidiasis. In this retrospective study, the outcome of candiduria was examined in a group of 54 pediatric patients to determine any predictors of disseminated candidiasis. Medical records were reviewed to identify urine collection methods, Candida colony counts, results of cultures from other body sites, antifungal therapy, and clinical course. Six (11%) of the 54 patients had evidence of systematic Candida infection. In only two of these patients was candiduria the first evidence of disseminated candidiasis. Invasive infection was associated with candiduria more frequently in neonates and patients with central venous catheters and/or immunosuppressive therapy. Urine colony counts were not helpful for assessing the risk of invasive disease. Candiduria appears to be of little consequence in patients who are generally healthy. However, candiduria in high-risk patients, even in the presence of perineal candidal infection or an indwelling urinary catheter, should prompt a careful evaluation for disseminated infection.

Prospective comparison of the immune response of infants to three Haemophilus influenzae type b vaccines

The antibody response to three Haemophilus influenzae type b vaccines was examined in 134 infants 17 to 22 months of age. Sera were collected from each subject before and 1 month after vaccination with either purified H. influenzae type b capsular polysaccharide (polyribosyl-ribitol phosphate (PRP] or one of two protein-conjugated vaccines (PRP-D or HbOC). Comparison of the two conjugate vaccines revealed that HbOC produced an antibody response greater than or equal to 1.0 micrograms/ml in 96% compared with 72% who were vaccinated with PRP-D (P less than 0.05). The isotype distribution of the antibodies produced by the two vaccines was similar. While all of the vaccines resulted in higher concentrations of anticapsular IgG1 than IgG2, the IgG1:IgG2 ratio was significantly higher in subjects immunized with HbOC. The IgG1:IgG2 ratio was similar in subjects immunized with PRP or PRP-D. The clinical significance of these observations remains to be determined.

Clinical manifestations of exacerbations of cystic fibrosis associated with nonbacterial infections

The purpose of this study was to determine whether acute pulmonary exacerbations of cystic fibrosis associated with nonbacterial infections are clinically distinguishable from other exacerbations. Eighty exacerbations in 54 patients were studied. Exacerbations associated with influenza (n = 8) were compared with those associated with other nonbacterial infections (n = 15) and those in which no nonbacterial infection was detected (n = 57). Patients with influenza had lower Shwachman scores and were more likely to be seropositive for C-reactive protein than patients in the other two groups. Patients with influenza had a mean decrease in forced expiratory volume per second of 26%, compared with test results obtained before the exacerbation. In contrast, the mean decrease in forced expiratory volume per second was 6% for other nonbacterial infections and 12% for the group without nonbacterial infection (p less than 0.05 for both comparisons). The forced expiratory flow in first 25% of vital capacity decreased 44% in the influenza group compared with 13% and 17% in the other two groups, respectively (p less than 0.01 for both comparisons). The influenza group also had a higher proportion of patients with at least a 20% decrease in forced expiratory volume per second and forced expiratory flow in first 25% of vital capacity than the other two groups had (p less than 0.05 for all comparisons). These data suggest that influenza is associated with severe exacerbations in patients with cystic fibrosis and support recommendations for efforts to prevent influenza in this population.

The high rate of blood donor exposure for critically ill neonates

The purpose of this study was to determine the number and volume of red blood cell (RBC) transfusions and the number of donors a newborn is exposed to during his or her newborn intensive care unit (NICU) stay. On one day at the Medical University of South Carolina (MUSC) and two days at the University of Virginia Hospital (UVH) all babies who had or were receiving RBCs comprised the study group. Patient records were reviewed at discharge. Fifty-two (70%) of the 75 NICU babies had or were receiving RBCs and were enrolled. The average number of RBC transfusions was nine (range 1 to 28, median 7) and the average transfusion volume was 16.5 ml (range 5 to 60) for a total volume of 148 ml transfused during a NICU stay. Each baby was exposed to an average of 6.9 donors (range 1 to 25, median 6.5). The practice of splitting RBC packs to share among different infants and of giving multiple small volume transfusions maximizes donor exposure and transfusion-related infectious risks in this population.

Accuracy of radiographic differentiation of bacterial from nonbacterial pneumonia

The chest roentgenogram is an accepted tool for the diagnosis of pneumonia. Little information is available, however, addressing the ability of physicians to distinguish bacterial from nonbacterial pneumonias by examination of the chest roentgenogram. Five different observers evaluated 36 chest films from patients with pneumonia who had a laboratory proven etiologic diagnosis. The sensitivity of roentgenogram diagnosis of bacterial pneumonia ranged from 42-58 percent. When clinical and laboratory data were provided to the observers the sensitivity ranged from 42-92 percent. This study indicates that chest film examination is too insensitive to be useful for the selection of patients who have bacterial pneumonia from those whose pneumonia is non-bacterial.