Agonists at GPR119 mediate secretion of GLP-1 from mouse enteroendocrine cells through glucose-independent pathways.

BACKGROUND AND PURPOSE: The G protein-coupled receptor 119 (GPR119) mediates insulin secretion from pancreatic ß cells and glucagon-like peptide 1 (GLP-1) release from intestinal L cells. While GPR119-mediated insulin secretion is glucose dependent, it is not clear whether or not GPR119-mediated GLP-1 secretion similarly requires glucose. This study was designed to address the glucose-dependence of GPR119-mediated GLP-1 secretion, and to explore the cellular mechanisms of hormone secretion in L cells versus those in ß cells. EXPERIMENTAL APPROACH: GLP-1 secretion in response to GPR119 agonists and ion channel modulators, with and without glucose, was analysed in the intestinal L cell line GLUTag, in primary intestinal cell cultures and in vivo. Insulin secretion from Min6 cells, a pancreatic ß cell line, was analysed for comparison. KEY RESULTS: In GLUTag cells, GPR119 agonists stimulated GLP-1 secretion both in the presence and in the absence of glucose. In primary mouse colon cultures, GPR119 agonists stimulated GLP-1 secretion under glucose-free conditions. Moreover, a GPR119 agonist increased plasma GLP-1 in mice without a glucose load. However, in Min6 cells, GPR119-mediated insulin secretion was glucose-dependent. Among the pharmacological agents tested in this study, nitrendipine, an L-type voltage-dependent calcium channel blocker, dose-dependently reduced GLP-1 secretion from GLUTag cells, but had no effect in Min6 cells in the absence of glucose. CONCLUSIONS AND IMPLICATIONS: Unlike that in pancreatic ß cells, GPR119-mediated GLP-1 secretion from intestinal L cells was glucose-independent in vitro and in vivo, probably because of a higher basal calcium tone in the L cells.

Sustained efficacy and immunogenicity of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine: analysis of a randomised placebo-controlled trial up to 6.4 years.

BACKGROUND: Prophylactic human papillomavirus (HPV) vaccines have to provide sustained protection. We assessed efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine up to 6.4 years. METHODS: Women aged 15-25 years, with normal cervical cytology, who were HPV-16/18 seronegative and oncogenic HPV DNA-negative (14 types) at screening participated in a double-blind, randomised, placebo-controlled initial study (n=1113; 560 vaccine group vs 553 placebo group) and follow-up study (n=776; 393 vs 383). 27 sites in three countries participated in the follow-up study. Cervical samples were tested every 6 months for HPV DNA. Management of abnormal cytologies was prespecified, and HPV-16/18 antibody titres were assessed. The primary objective was to assess long-term vaccine efficacy in the prevention of incident cervical infection with HPV 16 or HPV 18, or both. We report the analyses up to 6.4 years of this follow-up study and combined with the initial study. For the primary endpoint, the efficacy analysis was done in the according-to-protocol (ATP) cohort; the analysis of cervical intraepithelial neoplasia grade 2 and above (CIN2+) was done in the total vaccinated cohort (TVC). The study is registered with ClinicalTrials.gov, number NCT00120848. FINDINGS: For the combined analysis of the initial and follow-up studies, the ATP efficacy cohort included 465 women in the vaccine group and 454 in the placebo group; the TVC included 560 women in the vaccine group and 553 in the placebo group. Vaccine efficacy against incident infection with HPV 16/18 was 95.3% (95% CI 87.4-98.7) and against 12-month persistent infection was 100% (81.8-100). Vaccine efficacy against CIN2+ was 100% (51.3-100) for lesions associated with HPV-16/18 and 71.9% (20.6-91.9) for lesions independent of HPV DNA. Antibody concentrations by ELISA remained 12-fold or more higher than after natural infection (both antigens). Safety outcomes were similar between groups: during the follow-up study, 30 (8%) participants reported a serious adverse event in the vaccine group versus 37 (10%) in the placebo group. None was judged related or possibly related to vaccination, and no deaths occurred. INTERPRETATION: Our findings show excellent long-term efficacy, high and sustained immunogenicity, and favourable safety of the HPV-16/18 AS04-adjuvanted vaccine up to 6.4 years. FUNDING: GlaxoSmithKline Biologicals (Belgium).

Endogenous and synthetic agonists of GPR119 differ in signalling pathways and their effects on insulin secretion in MIN6c4 insulinoma cells.

BACKGROUND AND PURPOSE: GPR119 is a G protein-coupled receptor that is preferentially expressed in islet cells and mediates insulin secretion. Oleoyl-lysophosphatidylcholine and oleoylethanolamide (OEA) act as endogenous ligands for this receptor, whereas PSN375963 and PSN632408 are two recently reported synthetic agonists. In this study, we explored mechanisms underlying GPR119-induced insulin secretion. In addition, we assessed the potential utility of the synthetic agonists as tools for exploring GPR119 biology. EXPERIMENTAL APPROACH: We examined natural and synthetic GPR119 agonist activity at GPR119 in MIN6c4 and RINm5f insulinoma cells. We evaluated insulin secretion, intracellular calcium [Ca(2+)](i), ion channel involvement and levels of cAMP. KEY RESULTS: We report that increases in insulin secretion induced by OEA were associated with increased cAMP and a potentiation of glucose-stimulated increases in [Ca(2+)](i). We also demonstrate that ATP-sensitive K(+) and voltage-dependent calcium channels were required for GPR119-mediated increases in glucose-stimulated insulin secretion. In contrast to OEA, the synthetic GPR119 agonist PSN375963 and PSN632408 have divergent effects on insulin secretion, cAMP and intracellular calcium in MIN6c4 cells. CONCLUSIONS AND IMPLICATIONS: The endogenous ligand OEA signals through GPR119 in a manner similar to glucagon-like peptide-1 (GLP-1) and its receptor with respect to insulin secretion, [Ca(2+)](i) and cAMP. In addition, PSN375963 and PSN632408 substantially differ from OEA and from one another. These studies suggest that the commercially available synthetic agonists, although they do activate GPR119, may also activate GPR119-independent pathways and are thus unsuitable as GPR119-specific pharmacological tools.

Transgenic overexpression of neuromedin U promotes leanness and hypophagia in mice.

Recent work has shown that neuromedin U (NmU), a peptide initially identified as a smooth muscle contractor, may play a role in regulating food intake and energy homeostasis. To further evaluate this putative function, we measured food intake, body weight, energy expenditure and glucose homeostasis in transgenic mice that ubiquitously overexpress murine proNmU. NmU transgenic mice were lighter and had less somatic and liver fat, were hypophagic, and had improved insulin sensitivity as judged by an intraperitoneal insulin tolerance test. Transgenic mice had higher levels of hypothalamic NPY, POMC and MCH mRNA. There was no difference in O2 consumption between genotypes; however, NmU transgenic mice displayed a modest increase in respiratory quotient during food deprivation and refeeding. There were no behavioral disturbances in the NmU transgenic mice that could account for the results (e.g. changes in locomotor activity). When placed on a high-fat diet, transgenic mice remained lighter than wild-type mice and ate less, but gained weight at a rate similar to wild-type mice. Despite the increased weight gain with high-fat feeding, glucose tolerance was significantly improved in the transgenic mice. These findings support the hypothesized role of NmU as an endogenous anorexigenic peptide.

Centrally administered hemokinin-1 (HK-1), a neurokinin NK1 receptor agonist, produces substance P-like behavioral effects in mice and gerbils.

Hemokinin-1 (HK-1) is a recently described mouse tachykinin peptide whose biological functions are not fully understood. To date, a unique receptor for HK-1 has not been identified. Recent studies suggest HK-1 may have a role in immunological functions, but there has been little characterization of HK-1's effects in the central nervous system (CNS). In the present studies, we confirm that HK-1 is an endogenous agonist at all of the known tachykinin receptors, and is selective for the NK1 receptor over the NK2 and NK3 subtypes. CHO cells transfected with the human NK1 receptor released intracellular calcium in response to HK-1. In addition, HK-1 competed with substance P (SP) for binding to mouse NK1 and human NK1 receptors. In vivo central administration of HK-1 to gerbils and mice induced foot-tapping and scratching behaviors, respectively, similar to those observed following central administration of SP or the NK1 receptor agonist, GR-73632. Furthermore, these behavioral effects were blocked by the selective NK1 receptor antagonist, MK-869. Finally, a comprehensive expression analysis of HK-1 demonstrated that HK-1 mRNA is much more broadly expressed than previously reported with expression observed in many brain regions. Together these data demonstrate that HK-1 is a functional agonist at NK1 receptors and suggest that HK-1 may function both centrally and peripherally.

Disruption of neutrophil migration in a conditional transgenic model: evidence for CXCR2 desensitization in vivo.

We developed transgenic mice conditionally expressing the neutrophil chemoattracting chemokine KC and the beta-galactosidase gene in multiple tissues. In these transgenic mice, doxycycline treatment induced a strong up-regulation in the expression of KC in several tissues, including heart, liver, kidney, skin, and skeletal muscle. Expression of KC within these tissues led to a rapid and substantial increase in the serum levels of KC (serum KC levels were higher than 200 ng/ml 24 h after treatment). Accordingly, beta-galactosidase expression was also detected after injection of doxycycline and was highest in skeletal muscle, pancreas, and liver. Surprisingly, despite expression of KC in multiple tissues, no neutrophil infiltration was observed in any of the tissues examined, including skin. Doxycycline treatment of nontransgenic mice grafted with transgenic skin caused dense neutrophilic infiltration of the grafts, but not the surrounding host skin, indicating that the KC produced in transgenic tissues was biologically active. In separate experiments, neutrophil migration toward a localized source of recombinant KC was impaired in animals overexpressing KC but was normal in response to other neutrophil chemoattractants. Analysis of transgenic neutrophils revealed that high concentrations of KC in transgenic blood had no influence on L-selectin cell surface expression but caused desensitization of the receptor for KC, CXCR2. These results confirm the neutrophil chemoattractant properties of KC and provide a mechanistic explanation for the paradoxical lack of leukocyte infiltration observed in the presence of elevated concentrations of this chemokine.

Microbiology of acute otitis media recently treated with aminopenicillins.

INTRODUCTION: Sparse recent data are available in the United States regarding the pathogens of acute otitis media (AOM) most likely to be recovered from children recently treated with the two most frequently prescribed antibiotics, amoxicillin or amoxicillin/clavulanate (AMC). METHODS: Of the 704 rural Kentucky children with culture-positive AOM who underwent a single tympanocentesis or culture of otorrhea between 1992 and 1998, 96 pathogens were recovered from 90 children during therapy or within 7 days posttherapy with an aminopenicillin. Identification and susceptibility testing of AOM pathogens were performed by routine National Committee for Clinical Laboratory Standards methods. RESULTS: Pathogens recovered from children with AOM recently treated (0 to 7 days) with amoxicillin (n = 38) and AMC (n = 58), respectively, were as follows: Haemophilus influenzae (beta-lactamase-negative), 16 and 29%; H. influenzae (beta-lactamase-positive), 11 and 22%; penicillin-susceptible Streptococcus pneumoniae, 26 and 12%; intermediately penicillin-nonsusceptible S. pneumoniae (PNSP), 20 and 10%; resistant PNSP 13 and 17%; Moraxella catarrhalis (beta-lactamase-positive), 13 and 7%; and Streptococcus pyogenes, 3 and 2%. H. influenzae was also isolated from 8 (75%) of 12 children treated with high dose AMC ( approximately 80 mg/kg/day amoxicillin component). Significantly fewer children recently treated with amoxicillin were otitis-prone than those given AMC (24% vs. 74%, P < 0.0001). CONCLUSIONS: The predominant pathogen recovered from children with AOM recently treated with amoxicillin was S. pneumoniae (59%) rather than beta-lactamase-producing organisms (24%). H. influenzae was the predominant (51%) pathogen, rather than PNSP (27%), recovered from children recently treated with AMC.

Cefprozil versus high-dose amoxicillin/clavulanate in children with acute otitis media.

BACKGROUND: The recommendation of the Drug-Resistant Streptococcus pneumoniae Therapeutic Working Group that high-dose amoxicillin, with or without clavulanate, be used to treat acute otitis media (AOM) addressed concerns about the efficacy of existing therapies against drug-resistant S. pneumoniae. This recommendation relied on pharmacodynamic predictions of concentrations of amoxicillin in middle-ear fluid remaining higher than minimum inhibitory concentrations against intermediately resistant S. pneumoniae for >40% of the dosing interval. OBJECTIVE: This study compared the tolerability and efficacy of cefprozil and high-dose amoxicillin/clavulanate in patients with AOM. METHODS: Patients were randomized to receive 10 days of investigator-blinded oral treatment with either cefprozil suspension (30 mg/kg/d in 2 divided doses) or amoxicillin/clavulanate (45/6.4 mg/kg/d) plus amoxicillin (45 mg/kg/d) in 2 divided doses. The primary efficacy end point was the clinical cure rate 4 to 7 days after the end of treatment. Clinical response by age (6 months-<2 years vs > or =2-7 years), disease severity, and unilateral versus bilateral ear infection was also examined. The primary measures of tolerability were the frequency and severity of adverse events and their relation to study drug. Adverse events were either spontaneously reported or elicited during examination and questioning of the patient. Identified adverse events were coded and recorded using the COSTART (Coding Symbols for Thesaurus of Adverse Reaction Terms) system. RESULTS: Three hundred four children between the ages of 6 months and 7 years with > or =1 sign or symptom of AOM were enrolled in the study, and 303 (150 cefprozil, 153 amoxicillin/clavulanate) were treated. Twenty-three patients in each treatment group were not evaluable; thus, 257 children were included in the analysis of evaluable patients. Clinical cure rates were 87% (110/127) with cefprozil and 89% (116/130) with amoxicillin/clavulanate (95% CI for the difference in cure rate, -10.7% to 4.1%). No between-group differences in efficacy were noted by age, disease severity, or unilateral or bilateral involvement. The overall incidence of drug-related adverse events was significantly lower with cefprozil than with amoxicillin/clavulanate (19% vs 32%, respectively; P = 0.008), as was the incidence of diarrhea (9% vs 19%, respectively; P = 0.021). Adverse events prompted discontinuation of therapy in 4 (3%) cefprozil patients and 8 (5%) amoxicillin/clavulanate patients. CONCLUSIONS: Based on a search of MEDLINE, this study is the first direct comparison of cefprozil versus high-dose amoxicillin/clavulanate. Cefprozil was as effective as high-dose amoxicillin/clavulanate, with a lower incidence of adverse events.

Aberrant in vivo T helper type 2 cell response and impaired eosinophil recruitment in CC chemokine receptor 8 knockout mice.

Chemokine receptors transduce signals important for the function and trafficking of leukocytes. Recently, it has been shown that CC chemokine receptor (CCR)8 is selectively expressed by Th2 subsets, but its functional relevance is unclear. To address the biological role of CCR8, we generated CCR8 deficient (-/-) mice. Here we report defective T helper type 2 (Th2) immune responses in vivo in CCR8(-/)- mice in models of Schistosoma mansoni soluble egg antigen (SEA)-induced granuloma formation as well as ovalbumin (OVA)- and cockroach antigen (CRA)-induced allergic airway inflammation. In these mice, the response to SEA, OVA, and CRA showed impaired Th2 cytokine production that was associated with aberrant type 2 inflammation displaying a 50 to 80% reduction in eosinophils. In contrast, a prototypical Th1 immune response, elicited by Mycobacteria bovis purified protein derivative (PPD) was unaffected by CCR8 deficiency. Mechanistic analyses indicated that Th2 cells developed normally and that the reduction in eosinophil recruitment was likely due to systemic reduction in interleukin 5. These results indicate an important role for CCR8 in Th2 functional responses in vivo.

Cloning and characterization of a novel human histamine receptor.

Histamine exerts its numerous physiological functions through interaction with G protein-coupled receptors. Three such receptors have been defined at both the pharmacological and molecular level, while pharmacological evidence hints at the existence of further subtypes. We report here the cloning and characterization of a fourth histamine receptor subtype. Initially discovered in an expressed-sequence tag database, the full coding sequence (SP9144) was subsequently identified in chromosome 18 genomic sequence. This virtual coding sequence exhibited highest homology to the H(3) histamine receptor and was used to generate a full-length clone by polymerase chain reaction (PCR). The distribution of mRNA encoding SP9144 was restricted to cells of the immune system as determined by quantitative PCR. HEK-293 cells transiently transfected with SP9144 and a chimeric G protein alpha-subunit (Galpha(q/i1,2)) exhibited increases in intracellular [Ca(2+)] in response to histamine but not other biogenic amines. SP9144-transfected cells exhibited saturable, specific, high-affinity binding of [(3)H]histamine, which was potently inhibited by H(3) receptor-selective compounds. The rank order and potency of these compounds at SP9144 differed from the rank order at the H(3) receptor. Although SP9144 apparently coupled to Galpha(i), HEK-293 cells stably transfected with SP9144 did not exhibit histamine-mediated inhibition of forskolin-stimulated cAMP levels. However, both [(35)S]GTPgammaS binding and phosphorylation of mitogen-activated protein kinase were stimulated by histamine via SP9144 activation. In both of these assays, SP9144 exhibited evidence of constitutive activation. Taken together, these data demonstrate that SP9144 is a unique, fourth histamine receptor subtype.

Identification of a human gastrointestinal tract and immune system receptor for the peptide neuromedin U.

Neuromedin U (NmU) is a 25 amino acid peptide prominently expressed in the upper gastrointestinal (GI) tract and central nervous system. It is highly conserved throughout evolution and induces smooth muscle contraction in a variety of species. Our understanding of NmU biology has been limited because the identity of its receptor was unknown. Here we demonstrate that GPR66/FM-3 is specifically stimulated by NmU, causing the mobilization of intracellular calcium. This response was dose-dependent (EC(50) = 10 nM) and specific in that none of over 1000 ligands tested, including other neuromedins (NmB, C, L, K, N), induced a calcium flux in GPR66/FM-3-transfected cells. The GPR66/FM-3 mRNA is prominently expressed in the upper GI tract of humans, as is the mRNA for NmU, consistent with role for this receptor-ligand pair in regulating the function of this organ system. In addition, we show that whereas neuromedin U is expressed by monocytes and dendritic cells, GPR66/FM-3 is expressed by T cells and NK cells. These data suggest a previously unrecognized role for NmU as an immunoregulatory molecule.

Identification of a novel neuromedin U receptor subtype expressed in the central nervous system.

Neuromedin U is a neuropeptide prominently expressed in the upper gastrointestinal tract and central nervous system. Recently, GPR66/FM-3 (NmU-R1) was identified as a specific receptor for neuromedin U. A BLAST search of the GenBank(TM) genomic database using the NmU-R1 cDNA sequence revealed a human genomic fragment encoding a G protein-coupled receptor that we designated NmU-R2 based on its homology to NmU-R1. The full-length NmU-R2 cDNA was subsequently cloned, stably expressed in 293 cells, and shown to mobilize intracellular calcium in response to neuromedin U. This response was dose-dependent (EC(50) = 5 nm) and specific in that other neuromedins did not induce a calcium flux in receptor-transfected cells. Expression analysis of human NmU-R2 demonstrated its mRNA to be most highly expressed in central nervous system tissues. Based on these data, we conclude that NmU-R2 is a novel neuromedin U receptor subtype that is likely to mediate central nervous system-specific neuromedin U effects.

Clarithromycin suspension vs penicillin V suspension in children with streptococcal pharyngitis.

Clarithromycin, an advanced-generation macrolide antibiotic, has demonstrated excellent in vitro activity against group A beta-hemolytic streptococcus (GABHS). Potent activity against Streptococcus pyogenes and a favorable pharmacokinetic profile have made it a reasonable alternative for treatment of patients with streptococcal pharyngitis. The safety and efficacy of clarithromycin and penicillin V were compared in a randomized, investigator-blind study. Children 6 months to 12 years of age received 5 days of clarithromycin suspension 7.5 mg/kg twice daily (n = 268) or 10 days of penicillin V suspension 13.3 mg/kg three times daily (n = 260). Patients were evaluated for signs and symptoms of pharyngitis, and throat swabs for culture were obtained prior to therapy, at the end of therapy, and at follow-up. Clarithromycin and penicillin V produced comparable rates of clinical success (cure + improvement) at the posttreatment (97% and 94%) and follow-up (81% and 82%) evaluations. The GABHS eradication rate, however, was significantly higher with clarithromycin (94% vs 78%, P < .001). Both drugs were well tolerated; gastrointestinal complaints were similar and mild. Resistance did not occur with the short course of clarithromycin or the standard regimen of penicillin V. Five days' treatment with clarithromycin was superior to 10 days of penicillin in eradicating S. pyogenes.

Zanamivir for treatment of symptomatic influenza A and B infection in children five to twelve years of age: a randomized controlled trial.

BACKGROUND: Influenza infection rates are higher in children than in other age groups. This study evaluated the efficacy, safety and tolerability of a 5-day course of twice daily inhaled zanamivir, 10 mg, compared with placebo in the treatment of symptomatic influenza A and B viral infections among children 5 to 12 years of age. METHODS: This double blind, randomized, placebo-controlled, parallel group, multicenter study conducted in the Northern Hemisphere during the 1998 and 1999 influenza season enrolled 471 patients with influenza-like symptoms for < or = 36 h. Patients were randomly assigned to zanamivir (n = 224) or placebo (n = 247). Symptoms were recorded on diary cards twice daily during treatment, for 9 days after treatment and for 14 additional days (if still reporting moderate/severe cough and/or taking relief medication). FINDINGS: A total of 346 (73%) patients were influenza-positive by culture, serology or polymerase chain reaction (65% influenza A, 35% influenza B). Zanamivir reduced the median time to symptom alleviation by 1.25 days compared with placebo among patients with confirmed influenza infection (P < 0.001). Zanamivir-treated patients returned to normal activities significantly faster and took significantly fewer relief medications than placebo-treated patients. Zanamivir was well-tolerated, demonstrating adverse event profiles similar to those of placebo and no clinically significant changes in laboratory findings. Viral susceptibility testing revealed no zanamivir-resistant strains of influenza A or B. CONCLUSIONS: Zanamivir was effective in shortening the duration and severity of influenza symptoms and was well-tolerated among children 5 to 12 years of age.

Identification of viral macrophage inflammatory protein (vMIP)-II as a ligand for GPR5/XCR1.

Lymphotactin is unique among chemokines in that it contains only two of four conserved cysteines and may possess a structure less constrained than other chemokines. The viral chemokine vMIP-II, which presumably has a structure similar to that of CC chemokines has been shown to inhibit many chemokine receptors, but its activity at GPR5/XCR1 has not been described. Interestingly, vMIP-II (but not vMIP-I) was found to be a potent antagonist of lymphotactin activity at GPR5/XCR1, extending the range of chemokine classes that this viral protein is known to inhibit to include the C class chemokine. In addition, we have extended previous analyses of GPR5/XCR1 expression and show that this receptor is expressed in leukocyte cells previously shown to be responsive to lymphotactin.

Five-day twice daily cefdinir therapy for acute otitis media: microbiologic and clinical efficacy.

OBJECTIVE: To examine the microbiologic and clinical efficacy of a 5-day course of cefdinir in the treatment of tympanocentesis-documented acute otitis media (AOM). DESIGN: Open label noncomparative trial. SETTING: Primary care, ambulatory. PATIENTS: Children ages 6 months through 12 years with signs of AOM and middle ear effusion confirmed by tympanometry in at least one ear. INTERVENTION: Patients underwent tympanocentesis at baseline and received cefdinir 7 mg/kg twice a day for 5 days. MAIN OUTCOME MEASURES: Presumptive eradication of middle ear pathogens determined by clinical cure of signs and symptoms of AOM at end of therapy (Study Days 7 to 9) and Visit 3 (Study Days 16 to 21). RESULTS: A total of 125 of 177 enrolled children had 134 pathogens isolated by tympanocentesis: Streptococcus pneumoniae, 69 (51.5%); Haemophilus influenzae 44 (32.8%; beta-lactamase-positive in 18 of 44 strains); beta-lactamase-positive Moraxella catarrhalis, 15 (11.2%); and Streptococcus pyogenes, 6 (4.5%). The clinical cure rates by patient in the microbiologically and overall clinically evaluable groups, respectively, were 73% (84 of 115) and 77.4% (130 of 168) at the end of therapy visit and 57.4% (66 of 115) and 61.9% (104 of 168) at Visit 3. Presumptive eradication rates at end of therapy were 8 of 11 (72.7%) and 4 of 8 (50%) for patients with penicillin-intermediate and -resistant S. pneumoniae isolates, respectively. Adverse reactions occurred in 16% of patients, with diarrhea (11%) occurring most frequently. CONCLUSIONS: A 5-day regimen of cefdinir was effective in the eradication of the common causative pathogens of nonrefractory AOM, including intermediate penicillin-resistant S. pneumoniae and beta-lactamase-producing organisms. Cefdinir should be considered a suitable second line antibiotic for AOM.

Comparative safety and efficacy of cefdinir vs amoxicillin/clavulanate for treatment of suppurative acute otitis media in children.

OBJECTIVE: Two dosage regimens of cefdinir were compared with amoxicillin/clavulanate for the treatment of suppurative acute otitis media (AOM) in children. METHODS: This was an investigator-blinded, randomized, comparative, multicenter trial, in which tympanocentesis was performed in 384 patients, ages 6 months to 12 years, who had nonrefractory AOM. Patients were randomized to receive one of three 10-day treatment regimens: cefdinir 14 mg/kg daily (QD; n = 128); cefdinir 7 mg/kg twice a day (BID; n = 128); or amoxicillin/clavulanate 40/10 mg/kg/day divided for use three times a day (TID; n = 128). RESULTS: Of the 384 enrolled patients 303 were evaluable for clinical efficacy. Clinical success rates were statistically equivalent for the 3 treatment groups at the end of therapy: 85 of 102 (83.3%) for cefdinir QD; 81 of 101 (80.2%) for cefdinir BID; 86 of 100 (86%) for amoxicillin/clavulanate. Of the 197 evaluable patients from whom a susceptible pathogen was recovered, presumptive eradication rates at end of therapy were equivalent: 55 of 65 (84.6%), 54 of 66 (81.8%) and 55 of 66 (83.3%) for cefdinir QD-, cefdinir BID- and amoxicillin/clavulanate-treated patients, respectively. However, presumptive eradication rates for Streptococcus pneumoniae were significantly lower for cefdinir BID (55.2%) than for amoxicillin/clavulanate (89.5%; P = 0.0019) and marginally lower than for cefdinir QD (80%; P = 0.054). Diarrhea was the most common treatment-associated adverse reaction in all groups but was significantly more common in amoxicillin/clavulanate-treated patients (35%) than in patients who had been treated with cefdinir QD (10%, P<0.001) or cefdinir BID (13%, P<0.001). CONCLUSIONS: A 10-day regimen of cefdinir 14 mg/kg QD or 7 mg/kg BID was as clinically effective overall as a 10-day regimen of amoxicillin/ clavulanate 40/10 mg/kg/day divided TID in the treatment of tympanocentesis-confirmed, nonrefractory AOM in children. These data suggest that cefdinir QD may be a better alternative than cefdinir BID for refractory AOM. Both dosing regimens of cefdinir were associated with significantly fewer gastrointestinal adverse reactions than was amoxicillin/clavulanate.

The reduced expression of 6Ckine in the plt mouse results from the deletion of one of two 6Ckine genes.

6Ckine is an unusual chemokine capable of attracting naive T lymphocytes in vitro. It has been recently reported that lack of 6Ckine expression in lymphoid organs is a prominent characteristic of mice homozygous for the paucity of lymph node T cell (plt) mutation. These mice show reduced numbers of T cells in lymph nodes, Peyer's patches, and the white pulp of the spleen. The genetic reason for the lack of 6Ckine expression in the plt mouse, however, has remained unknown. Here we demonstrate that mouse 6Ckine is encoded by two genes, one of which is expressed in lymphoid organs and is deleted in plt mice. A second 6Ckine gene is intact and expressed in the plt mouse.

The assignment of chemokine-chemokine receptor pairs: TARC and MIP-1 beta are not ligands for human CC-chemokine receptor 8.

Identification of chemokine receptors and their associated ligands is crucial to the understanding of most immune reactions. Three human chemokines [I-309, thymus and activation-regulated chemokine (TARC) and macrophage inflammatory protein-1beta (MIP-1beta)] have been reported to be ligands for CC-chemokine receptor 8 (CCR8). In this report, we present evidence that TARC and MIP-1beta did not bind to or induce chemotaxis through CCR8 on a stable transfected cell line (1D-21) and did not bind to CCR8 on in vitro differentiated human CD4(+) Th(2) cell cultures. Also, I-309-dependent calcium mobilization in 1D-21 cells and in Th(2) cells was desensitized by I-309 but not by MIP-1beta or TARC. These results provide strong evidence that, at physiologically relevant concentrations, I-309 is the only known human ligand for CCR8. These data also provide a framework for suggesting minimum requirements for the assignment of chemokine receptor-ligand pairs.