Impaired infiltration of tumor-specific cytolytic T cells in the absence of interferon-gamma despite their normal maturation in lymphoid organs during CD137 monoclonal antibody therapy

Engagement of CD137 receptor by agonistic monoclonal antibodies (mAb) stimulates IFN-gamma production and eradicates established tumors in syngeneic mouse models. Using IFN-gamma-deficient mice or neutralizing mAb, we demonstrate that IFN-gamma is an absolute requirement for the antitumor effect of CD137 mAb. Despite progressive tumor growth in IFN-gamma-depleted mice, a fully competent CD8(+) cytolytic T cell (CTL) response developed in the lymph nodes. In addition, tumor cell sensitivity to IFN-gamma was not required because expression of a dominant-negative IFN-gamma receptor on the tumor did not affect the therapeutic effect of CD137 mAb. However, in the absence of IFN-gamma, the number of tumor-infiltrating CD8(+) CTLs was drastically decreased. Our results demonstrate that IFN-gamma is a critical factor regulating the infiltration of antigen-specific CTL into the tumor.     

Association of white blood cell count with increased mortality in acute myocardial infarction and unstable angina pectoris. OPUS-TIMI 16 Investigators

We observed in a study of 7,651 patients with acute coronary syndromes that a white blood cell (WBC) count of > 10,000 was associated with increased 30-day and 10-month mortality (6.2% vs 3.2% to 3.6% for WBC count < 10,000; p < 0.000). With its simplicity and widespread availability, WBC count could serve as a simple, inexpensive, new tool for risk stratification in acute coronary syndromes.     

The Yang-Monti ileovesicostomy: a problematic channel?

OBJECTIVE: To compare the differences in the quality of Mitrofanoff channels created using appendix and re-tubularized small bowel (the Yang-Monti ileovesicostomy). Patients and methods The case-notes were reviewed retrospectively for all patients who underwent a Mitrofanoff procedure using either appendix or small bowel, over a 5-year period from June 1994 to July 1999. RESULTS: In all, 92 patients underwent 94 Mitrofanoff procedures; the appendix was used in 69 and small bowel in 25. The underlying diagnoses were exstrophy-epispadias complex (38), neuropathic bladder (21), anorectal malformations and cloacal anomalies (15), posterior urethral valves (nine) and miscellaneous (nine). The mean (range) age at operation was 9.2 (1.1-18.3) years. The mean (range) follow-up for the appendix group was 37 (6.7-65) months and for the Monti group 25 (6-66) months. Catheterization problems occurred in 18 (27%) patients from the appendix group; two needed an adjustment of technique, six dilatation and 10 revision. Stomal stenosis occurred in 10 (15%) patients, bladder level stenosis in four (6%) and conduit necrosis in two. Catheterization problems were reported in 15 (60%) patients from the Monti group; five needed revision, three dilatation and seven are being managed conservatively. The incidences of stomal stenosis (four, 16%) and bladder level stenosis (two, 8%) were comparable with the appendix group. In addition, two patients had distal channel (sub-stomal) stenosis and two had mid-channel stenosis. The problem unique to the Yang-Monti channel was a pouch-like dilatation in seven patients (28%), all of whom presented with catheterization problems; five are being managed conservatively and two have needed pouch resection. Stomal prolapse occurred in five (7%) patients in the appendix group, but in none of the Monti group. CONCLUSIONS: The appendix is the conduit of choice for a Mitrofanoff procedure. Re-tubularized small bowel conduits have a considerably higher incidence of catheterization problems. Anatomical factors may contribute to the unique incidence of pouch formation.     

Prevalence and nature of connexin 26 mutations in children with non-syndromic deafness

OBJECTIVE: To determine (1) the prevalence and nature of connexin 26 mutations in a cohort of Australian children with non-syndromic hearing loss, and (2) the carrier frequency of the common connexin 26 mutation (35delG) in the general population. DESIGN: A cohort, case-finding study. Mutation analysis was performed on DNA extracted from white blood cells, buccal cells, or Guthrie blood spots. SETTING: A hearing loss investigation clinic and a deafness centre in two Australian capital cities, 1 January 1998 to 31 October 2000. PARTICIPANTS: (1) 243 children (age range, 4 weeks to 16 years; median, 4 years), attending hearing loss clinics in Sydney and Melbourne; (2) 1000 blood samples obtained from anonymous Guthrie card blood spots collected in 1984 [corrected] by the Victorian Clinical Genetics Service as part of the newborn screening program. MAIN OUTCOME MEASURES: (1) The prevalence and types of connexin 26 mutations in a cohort of children with prelingual deafness; (2) the carrier frequency of the common connexin 26 mutation, 35delG, in the general population. RESULTS: Connexin 26 mutations were identified and characterised in 52 (21%) of the 243 children; 14 different mutations, including four previously unreported mutations (135S, C53R, T123N and R127C), were identified. The common 35delG mutation was found in 56 of the 104 alleles (ie, 86 of the connexin 26 alleles in which a mutation was positively identified). The mutations V371 and M34T were also relatively common. The carrier frequency of connexin 26 mutations and of the common 35delG connexin 26 mutation in the Victorian population was estimated to be 1 in 54 and 1 in 100, respectively. CONCLUSIONS: Mutations in the connexin 26 gene (especially the 35delG mutation) are a common cause of prelingual hearing loss in Australia.     

Inhibition of ADP-induced P-selectin expression and platelet-leukocyte conjugate formation by clopidogrel and the P2Y12 receptor antagonist AR-C69931MX but not aspirin

Platelet-leukocyte interactions are recognised to have pro-inflammatory effects, which may be important in the pathophysiology of ischaemic heart disease. Clopidogrel and the novel intravenous antithrombotic agent AR-C69931MX act at the level of the platelet P2Y12 receptor, which is known to amplify platelet activation, aggregation and other responses induced by numerous platelet agonists. We studied the effects of clopidogrel and aspirin on ADP-induced platelet-leukocyte conjugate formation and P-selectin expression in healthy volunteers. The effects of clopidogrel and AR-C69931MX administered to patients with ischaemic heart disease were also assessed. AR-C69931MX and aspirin were also studied in vitro. Clopidogrel and AR-C69931MX suppressed ADP-induced platelet aggregation, P-selectin expression and platelet-leukocyte conjugate formation whereas aspirin had no inhibitory effect. These effects of clopidogrel and AR-C69931MX may confer therapeutic benefits in the management of acute coronary syndromes.     

Latency in vitro of varicella-zoster virus in cells derived from human fetal dorsal root ganglia.

A potential in vitro model of varicella-zoster virus (VZV) latency was developed. Dissociated human dorsal root ganglion cultures were infected with VZV and maintained for 1 wk in the presence of bromovinyl arabinosyl uracil, a potent inhibitor of VZV. Seven to 21 d after removing the inhibitor (> or = 14 d after infection), the cells were trypsinized, passed to monolayers of human embryonic lung fibroblasts, and observed for VZV reactivation as indicated by typical cytopathic effects and the appearance of VZV antigens. VZV reactivated from 56% of the cultures containing both neurons and satellite cells but not from cultures specifically enriched for either neurons, satellite cells, or ganglion-derived fibroblasts. The failure to isolate VZV from cell suspensions that were sonicated before cocultivation with fibroblasts indicated that infectious VZV was not present before reactivation. Moreover, immunohistochemical and immunoprecipitation studies revealed no VZV-specific antigens in any cultures before the reactivation stimulus. VZV antigens were detected after trypsinization and cocultivation. These findings suggest that cultures containing both neurons and satellite cells provide a model system for VZV persistence that possesses many properties of a latent infection.     

Emergence of vancomycin resistance in Staphylococcus aureus. Glycopeptide-Intermediate Staphylococcus aureus Working Group

BACKGROUND: Since the emergence of methicillin-resistant Staphylococcus aureus, the glycopeptide vancomycin has been the only uniformly effective treatment for staphylococcal infections. In 1997, two infections due to S. aureus with reduced susceptibility to vancomycin were identified in the United States. METHODS: We investigated the two patients with infections due to S. aureus with intermediate resistance to glycopeptides, as defined by a minimal inhibitory concentration of vancomycin of 8 to 16 microg per milliliter. To assess the carriage and transmission of these strains of S. aureus, we cultured samples from the patients and their contacts and evaluated the isolates. RESULTS: The first patient was a 59-year-old man in Michigan with diabetes mellitus and chronic renal failure. Peritonitis due to S. aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S. aureus peritonitis associated with dialysis. The removal of the peritoneal catheter plus treatment with rifampin and trimethoprim-sulfamethoxazole eradicated the infection. The second patient was a 66-year-old man with diabetes in New Jersey. A bloodstream infection due to S. aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S. aureus bacteremia. This infection was eradicated with vancomycin, gentamicin, and rifampin. Both patients died. The glycopeptide-intermediate S. aureus isolates differed by two bands on pulsed-field gel electrophoresis. On electron microscopy, the isolates from the infected patients had thicker extracellular matrixes than control methicillin-resistant S. aureus isolates. No carriage was documented among 177 contacts of the two patients. CONCLUSIONS: The emergence of S. aureus with intermediate resistance to glycopeptides emphasizes the importance of the prudent use of antibiotics, the laboratory capacity to identify resistant strains, and the use of infection-control precautions to prevent transmission.     

Functional interactions between tumor and peripheral nerve in a model of cancer pain in the mouse

Cancer is usually accompanied by pain, which tends to increase in relation to metastatic infiltration and destruction. In the United States, 30% to 40% of newly diagnosed cancer patients and 67% to 90% of patients with advanced cancer report moderate to severe pain. Relief for approximately 90% of patients with cancer-related pain may be provided by the World Health Organization's "analgesic ladder," which involves progressing from non-opioid (e.g., acetaminophen, ibuprofen) to weak opioid (e.g., codeine), to strong opioid (e.g., morphine, fentanyl) intervention for pain relief. The severity of cancer pain is affected by diverse factors. In addition to the obvious factors of tumor size and degree of metastatic destruction, the type of tumor and its location are also important factors that contribute to pain severity. Severe cancer pain is especially associated with tumors involving bone destruction and nerve infiltration. Cancer pain seems to involve diverse mechanisms, including characteristics of both nociceptive and neuropathic pain. Unfortunately, even opioid analgesics often produce poor pain relief against neuropathic pain derived from peripheral nerve or root damage common to cancers involving bone metastases and nerve infiltration. In addition, these drugs may induce adverse side effects since they affect various physiological functions, including hormone secretion, neurotransmitter release, feeding, gastrointestinal motility, and respiratory activity. Currently, drug therapies utilizing antidepressants and anticonvulsants are being used to relieve neuropathic pain whereas cancer pain is treated largely with opiods in cancer patients.     

3’- and 4’-chloro-substituted analogs of benztropine: intravenous self-administration and in vitro radioligand binding studies in rhesus monkeys

Rationale: The reinforcing effects of many psychomotor stimulants have been related to increased dopaminergic neurotransmission. Drugs that block dopamine (DA) uptake have generally been found to function as positive reinforcers. Benztropine (BZT) and several of its halogenated analogs have previously been characterized as potent DA-uptake inhibitors with behavioral profiles that indicate diminished psychomotor stimulant effects relative to cocaine. Objectives: The present experiments were designed to examine, in rhesus monkeys, the reinforcing effects of the DA-uptake inhibitor BZT and two chloro-analogs 3’-C1-BZT and 4’-Cl-BZT, and to compare self-administration and binding profiles. Methods: Four rhesus monkeys self-administered cocaine i.v. under a fixed-ratio 10 (FR10) schedule until stable responding was established. Saline, and various doses of cocaine, BZT, and the BZT analogs were then made available for self-administration. Binding of these compounds to monoaminergic and cholinergic sites in monkey brain were determined using standard radioligand binding techniques. Results: Self-administration was maintained by both 3’-C1-BZT and 4’-Cl-BZT, but not by BZT. Results suggested that 3’-C1-BZT and 4’-Cl-BZT were weak positive reinforcers. BZT and analogs bound DA transporters (DAT) with affinities higher than that of cocaine and had affinity for muscarinic binding sites. Conclusions: Surprisingly, high affinity at DATs was associated with weak or no reinforcing effects. The mechanism(s) that may underlie this dissociation between DAT actions and reinforcing effects remains to be established. These data support the proposal that a lead for the discovery of a pharmacotherapeutic agent for cocaine abuse may come from this group of compounds. Received: 24 May 1999 / Final version: 28 July 1999