Analgesic effectiveness of subcutaneous carbon-dioxide insufflations as an adjunct treatment in patients with non-specific neck or low back pain.

OBJECTIVES: To evaluate the analgesic effectiveness of subcutaneous carbon-dioxide insufflations in addition to standard physical treatment in patients with non-specific neck or low back pain. DESIGN: A pragmatic, randomized controlled trial. SETTING: Rehabilitation hospital inpatients. INTERVENTIONS: Patients received either subcutaneous carbon-dioxide insufflations (10 treatments) and standard physical treatment or standard physical treatment only. OUTCOME MEASURES: Affective pain perception (42-point scale), sensory pain perception (30-point scale), pain intensity (100 mm visual analogue scale). RESULTS: Between-groups differences were -2.2 [95% CI -5.2; +0.9] (affective pain perception), -1.2 [-3, 0; + 0.7] (sensory pain perception), and -6.5 [-14; +1.0] (pain intensity) respectively in favour of subcutaneous carbon-dioxide insufflations. CONCLUSIONS: Subcutaneous carbon-dioxide insufflations do not seem to be a worthwhile adjunct in the given setting of inpatient rehabilitation. Trials in a monotherapeutic setting, which aim more at the efficacy of subcutaneous carbon-dioxide insufflations, might help to solve this issue.

Clinical evidence of subcutaneous CO2 insufflations: a systematic review.

OBJECTIVE: To evaluate the evidence of clinical effectiveness of subcutaneous CO2 insufflations (SCIs). STUDY LOCATION: The entire databases of MEDLINE, EMBASE Excerpta Medica (Field: Rehabilitation and Physical Medicine) and the Cochrane Library were screened for data up to August 1999. In addition, other potentially relevant journals were handsearched and references were checked. STUDY SELECTION: Uncontrolled observational trials (UCOTs) with sample sizes of at least n = 100, and controlled clinical trials (CCTs) and randomized controlled trials (RCTs) were included. Outcomes had to be patient-centered. English-, Czechoslovakian-, and German-language papers were considered. DATA ANALYSIS: For all study types, a criteria-based analysis was performed. For controlled trials only, quality was quantitatively assessed with the Jadad and Maastricht Scales. RESULTS: Thirteen studies (5 RCTs, 2 CCTs, and 6 UCOTs) were included. Mean scores on the Jadad and Maastricht Scales were 2 (Maximum 5) and 37 (Maximum 100), respectively. SCIs were found to be effective in addition to standard physical therapy in "peripheral arterial occlusive disease" (2 RCTs) and "stable angina pectoris" (1 RCT) and superior to sham needling for migraine headaches (1 RCT). There were no differences among SCIs and CO2 gas baths (1 RCT) or combined interventions, including SCIs (2 CCTs). All 6 UCOTs showed marked longitudinal effects. CONCLUSIONS: The low number and quality of the available studies precludes firm conclusions on the clinical effectiveness of SCIs.

Autocrine signals control CCAAT/enhancer binding protein beta expression, localization, and activity in macrophages.

The transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta, or NF-IL6) is expressed in macrophages, where it participates in lipopolysaccharide (LPS)-mediated induction of proinflammatory cytokine genes such as interleukin-6 (IL-6) and IL-1beta. We have identified activities in conditioned medium from a macrophage tumor cell line that regulates the expression, localization, and transcriptional activity of C/EBPbeta. One factor was shown to be tumor necrosis factor- (TNF-), which increased C/EBPbeta expression by a posttranscriptional mechanism. A second activity, designated autocrine macrophage factor (AMF), elicited a change in C/EBPbeta localization from a punctate nuclear staining pattern to diffuse nuclear distribution. The punctate form of C/EBPbeta correlated with increased susceptibility of this protein to cleavage by an endogenous protease during nuclear extract preparation. Conditioned medium stimulated the ability of C/EBPbeta to transactivate a reporter gene and activated the expression of two cytokine genes that are putative targets of C/EBPbeta. These observations suggest that diffuse distribution of C/EBPbeta in the nucleus corresponds to an activated form of this protein. AMF activity could not be mimicked by an extensive set of recombinant cytokines and growth factors and therefore may represent a novel extracellular factor.

Tumor necrosis factor alpha transcription in macrophages is attenuated by an autocrine factor that preferentially induces NF-kappaB p50.

Macrophages are a major source of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha), which are expressed during conditions of inflammation, infection, or injury. We identified an activity secreted by a macrophage tumor cell line that negatively regulates bacterial lipopolysaccharide (LPS)-induced expression of TNF-alpha. This activity, termed TNF-alpha-inhibiting factor (TIF), suppressed the induction of TNF-alpha expression in macrophages, whereas induction of three other proinflammatory cytokines (interleukin-1beta [IL-1beta], IL-6, and monocyte chemoattractant protein 1) was accelerated or enhanced. A similar or identical inhibitory activity was secreted by IC-21 macrophages following LPS stimulation. Inhibition of TNF-alpha expression by macrophage conditioned medium was associated with selective induction of the NF-kappaB p50 subunit. Hyperinduction of p50 occurred with delayed kinetics in LPS-stimulated macrophages but not in fibroblasts. Overexpression of p50 blocked LPS-induced transcription from a TNF-alpha promoter reporter construct, showing that this transcription factor is an inhibitor of the TNF-alpha gene. Repression of the TNF-alpha promoter by TIF required a distal region that includes three NF-kappaB binding sites with preferential affinity for p50 homodimers. Thus, the selective repression of the TNF-alpha promoter by TIF may be explained by the specific binding of inhibitory p50 homodimers. We propose that TIF serves as a negative autocrine signal to attenuate TNF-alpha expression in activated macrophages. TIF is distinct from the known TNF-alpha-inhibiting factors IL-4, IL-10, and transforming growth factor beta and may represent a novel cytokine.

CRP2 (C/EBP beta) contains a bipartite regulatory domain that controls transcriptional activation, DNA binding and cell specificity.

Two members of the C/EBP family of basic region-leucine zipper proteins enriched in the liver, C/EBP (C/EBP alpha) and CRP2 (C/EBP beta), were previously shown to transactivate the albumin promoter in a cell type-dependent manner. These proteins function efficiently in HepG2 hepatoma cells, but inefficiently in HeLa (epithelial) and L (fibroblastic) cells. Here we have investigated the mechanism for cell-specific control of CRP2 activity. We show that CRP2 contains a negative regulatory region composed of two elements, RD1 and RD2. Deletions of RD2 relieve the inhibition of CRP2 activity in L cells, but do not affect CRP2 function in HepG2 cells. These deletions also increase the DNA binding activity of CRP2 approximately 3-fold, suggesting that RD2-mediated repression of DNA binding activity is responsible for CRP2 inhibition in L cells. The adjacent RD1 element functions independently of RD2 and modulates the CRP2 activation domain, which we show to be composed of three subdomains that are conserved within the C/EBP protein family. RD1 does not affect cell type specificity, but inhibits the transactivation potential of GAL4-CRP2 hybrid proteins by 50-fold. These findings suggest that CRP2 assumes a tightly folded conformation in which the DNA binding and activation domains are masked by interactions with the regulatory domain and that to function efficiently in HepG2 cells the protein must undergo an activation step. We propose that relief of inhibition conferred by the regulatory domains also accounts for CRP2 activation in response to extracellular signals.

An HSV-1 containing the rat beta-glucuronidase cDNA inserted within the LAT gene is less efficient than the parental strain at establishing a transcriptionally active state during latency in neurons.

The herpes simplex virus vector 17/LAT-RGUSB has previously been shown to express beta-glucuronidase enzyme activity stably in the trigeminal ganglia and brain stems of beta-glucuronidase-deficient mutant mice. However, the number of beta-glucuronidase expressing cells in trigeminal ganglia latently infected with 17/LAT-RGUSB was smaller than expected. Using normal mice for further characterization of 17/LAT-RGUSB latent infection, no appreciable differences were found between the vector and wild-type virus in: (1) their abilities to replicate in acutely infected ganglia; (2) their abilities to reactivate from latently infected ganglia: or (3) the quantities of viral DNA in tissues during the acute or the latent phases of infection. Using a minor LAT (mLAT)-specific probe to detect transcription by in situ hybridization, it was found that the intensity of the signal from individual cells latently-infected with 17/LAT-RGUSB or wild-type virus was similar. However, the vector-infected ganglia had only 20% as many positive cells as in wild-type infection. These data suggest that 17/LAT-RGUSB virus established latency similarly to wild-type virus, but that the LAT-promoter driven gene expression was compromised.

A thymidine kinase-negative HSV-1 strain establishes a persistent infection in SCID mice that features uncontrolled peripheral replication but only marginal nervous system involvement.

A detailed knowledge of the pathogenesis of infections caused by thymidine-kinase (TK)-deficient herpes simplex virus type 1 (HSV-1) strains is important because such mutants can arise during treatment of HSV infections with acyclovir--especially in immunocompromised patients--and also because TK-negative mutants may become useful for the therapy of intracranial tumors. In this work, we studied the pathogenesis of a genetically engineered TK-negative HSV-1 strain dlsptk, in SCID mice (mice with severe combined immunodeficiency) after corneal infection. We found that dlsptk established a persistent infection that kills SCID mice within 80.2 +/- 21.3 days. The cause of death seemed to be related to uncontrolled viral replication in the superficial and deep facial tissues of the animals. Viremia probably did not occur, as judged by the inability to detect infectious virus and viral gene expression in various internal organs. However, the virus did reach the nervous system, most probably by axonal transport from the primary site of the infection. Virus-specific DNA reached low but detectable levels in the trigeminal ganglia and the brainstems by 7 days p.i. and remained at low levels for up to 50 days p.i. as determined by spot blot analysis. By in situ hybridization and immunostaining we determined that, in some of the neurons of the trigeminal ganglia infected by the virus, viral latency was established. However, our results suggested that in other infected neurons viral replication occurred and virus spread to surrounding nonneuronal cells and to the central nervous system. This work provides a new model in which the pathogenesis of infections caused by TK-deficient HSV strains in immunocompromised hosts can be effectively studied and which may also help to identify the potential side effects of the therapy of intracranial tumors with TK-negative HSV strains.

An HSV-1 mutant lacking the LAT TATA element reactivates normally in explant cocultivation.

In order to examine if mutations within the LAT promoter region of HSV-1 are sufficient to change the reactivation phenotype, a mutant (KOS/29) containing a deletion of the LAT TATA element was used to establish latent infections in mouse ganglia by corneal inoculation. During the acute phase of infection, KOS/29 replicated as efficiently as its wild-type parent. As previously noted, latent KOS/29 infections were totally devoid of LAT gene transcripts (Dobson A. T., Sederati F., Devi-Rao G., Flanagan J., Farrell M. J., Stevens J. G., Wagner E. K., and Feldman L. T., J. Virol. 63, 3844-3851 (1989))). However, unlike other null mutants, KOS/29 reactivated from explanted ganglia with a kinetics similar to that of the LAT competent parent. These data show that the deletion created in KOS/29, removing the LAT TATA promoter element and small upstream and downstream flanking sequences, is not enough to alter the reactivation phenotype and that efficient reactivation can occur in the absence of any detectable LAT expression during latency.

A mouse model for varicella-zoster virus latency.

Following primary infection with varicella-zoster virus (VZV), the virus establishes a latent infection in humans. The molecular pathogenesis of VZV latency is not well understood, mainly due to the lack of an adequate animal model. We report here that we have developed a mouse model for VZV infection that involves corneal inoculation of mice. Although infected animals showed no signs of disease, most of the animals could not eliminate the virus early after infection. By PCR, we demonstrated that at 33 days post-infection (p.i.), viral DNA was still present in more than 60% of the animals (14/21). VZV DNA was most frequently detected in the trigeminal ganglia (7/14) followed by the brain stem (10/21), kidneys (4/21), spleen (3/20), liver (2/21) and brain (1/21). By in situ hybridization, a few cells positive for VZV mRNA were detected in the trigeminal ganglia, brain stem, cerebellum and spleen of a small number of the infected animals as late as 33 days p.i. No viral proteins were detected at the site of inoculation or in any other tissue by immunostaining. Our results suggest that VZV spreads in mice by both viraemia and axonal transport and establishes a non-productive (latent) infection.

Herpes simplex virus type 1 mutant strain in1814 establishes a unique, slowly progressing infection in SCID mice.

Ocular infection of immunocompetent (BALB/c) mice with wild-type herpes simplex virus type 1 (HSV-1) 17+ may lead to acute fatal encephalitis; however, in surviving animals, a latent (nonproductive) infection of the nervous system is established. In contrast, 17+ infection invariably kills mice with severe combined immunodeficiency (SCID mice) within 2 weeks. Ocular infection of immunocompetent mice with a mutant HSV-1 strain, in1814, which does not produce a functional alpha-transinducing protein, results in no detectable viral replication in the nervous system during the time corresponding to the acute phase of infection, no mortality, and the establishment of latency. In SCID mice, however, the in1814 virus establishes a unique, slowly progressing infection. In studying the courses of in1814 infection in SCID and BALB/c mice, we found that although intact B- and/or T-lymphocytic functions were required for the control of viral replication in the nervous system, some of the infected neurons of SCID mice seemed to be able to restrict in1814 replication and harbor the virus in a latent state.

Induction of cellular transcription factors in trigeminal ganglia of mice by corneal scarification, herpes simplex virus type 1 infection, and explantation of trigeminal ganglia.

In a mouse model for herpes simplex virus type 1 (HSV-1) latency in which the virus was inoculated via the eye after corneal scarification, HSV-1 replicated in corneal epithelial cells and infected the nerve cell endings. HSV-1 reached the trigeminal ganglia by fast axonal transport between 2 and 10 days postinfection (p.i.) and established a latent infection in neuronal cells or replicated and spread to nonneuronal cells. By using in situ hybridization, we showed that cellular transcription factors are stimulated by HSV-1 infection in trigeminal ganglia. This stimulation is biphasic, peaking at 1 and 3 to 4 days p.i. The first peak involves c-jun and oct-1 expression in neurons, and the second involves c-jun, c-fos, and oct-1 expression in neurons and nonneuronal cells. Corneal scarification, alone or followed by infection with UV-inactivated HSV-1, induced monophasic c-jun and oct-1 expression in some neurons of the trigeminal ganglia, with a peak at 1 day p.i. Corneal infection without prior scarification induced c-jun, c-fos, and oct-1 expression in some neuronal and nonneuronal cells of the trigeminal ganglia 2 to 9 days p.i. Explanation of ganglia from latently infected animals resulted in reactivation of the latent virus. Independently of the presence of latent HSV-1 in explanted ganglia, expression of c-fos, c-jun, and oct-1 was induced first in nonneuronal cells, peaking 6 to 10 h postexplantation, and then in neuronal cells, with a peak at 24 h after explantation when expression of viral replicative genes was first detectable. Since ocular HSV-1 infection, corneal scarification, and explantation of trigeminal ganglia all resulted in induction of expression of cellular transcription factors in ganglia, these factors may play a critical role in the permissiveness of cells for HSV-1 replication during acute infection, latency, and reactivation.