Chronic use of non-steroidal anti-inflammatory drugs does not alter colonic mucosa of patients without diarrhoea

BACKGROUND

Several types of colitis can be NSAID-induced, but whether chronic use of NSAIDs alters colonic mucosa in patients without diarrhoea is not known.

PATIENTS AND METHODS

Biopsy specimens of rectal mucosa were taken in six patients with rheumatoid arthritis without diarrhoea receiving NSAIDs (group 1, n=6). Patients with rheumatoid arthritis without diarrhoea not receiving NSAIDs (group 2, n=9), and patients undergoing surveillance colonoscopy (group 3, n=23) served as controls. In all patients from the three study groups, intraepithelial lymphocyte count and apoptotic cell count were assessed, and sub-epithelial collagen band thickness was measured. Leucocyte population of lamina propria was evaluated semi-quantitatively. HLA-DR and CD25 expression of mucosal cells was appreciated by immunohistochemistry.

RESULTS

Intraepithelial lymphocyte count was in the normal range in all three group patients, and not statistically different between groups. Apoptotic epithelial cell count was not different between groups. Sub-epithelial collagen band thickness was normal in all the patients. No patient had a marked infiltration of lamina propria by leucocytes, and HLA-DR and CD25 were normally expressed in all patients.

CONCLUSION

These results from a small sample of patients suggest that patients without diarrhoea receiving NSAIDs on a long-term basis do not develop microscopic or inflammatory colitis.

Similarity of the song nuclei of male and female Australian magpies (Gymnorhina tibicen)

The organisation of the song control nuclei of the Australian magpie (Gymnorhina tibicen), a species with highly complex song, was investigated. In contrast to most of the songbirds studied so far, the Australian magpie sings throughout the year and both males and females sing. All of the forebrain song nuclei, including the high vocal centre (HVC), the robust nucleus of the archistriatum (RA), Area X and the lateral and medial magnocellular nuclei of the anterior neostriatum (lMAN and mMAN) were found to be well developed in both male and female magpies. Consistent with the known vocal competence of juvenile magpies, all of the song nuclei were also well-developed in juvenile magpies (2--3 months old). HVC in both male and female magpies consists of a rostrolateral and a caudomedial region. The ventromedial part of RA differs from the dorsolateral part by having medium-sized neurons packed in higher density. The HVC to RA projections were labelled anterogradely by DiI and DiA. However, no HVC to Area X projections were labeled by DiI or DiA, suggesting a possible difference from songbirds studied previously.

Income inequality, the psychosocial environment, and health: comparisons of wealthy nations

BACKGROUND

The theory that income inequality and characteristics of the psychosocial environment (indexed by such things as social capital and sense of control over life's circumstances) are key determinants of health and could account for health differences between countries has become influential in health inequalities research and for population health policy.

METHODS

We examined cross-sectional associations between income inequality and low birthweight, life expectancy, self-rated health, and age-specific and cause-specific mortality among countries providing data in wave III (around 1989-92) of the Luxembourg Income Study. We also used data from the 1990-91 wave of the World Values Survey (WVS). We obtained life expectancy, mortality, and low birthweight data from the WHO Statistical Information System.

FINDINGS

Among the countries studied, higher income inequality was strongly associated with greater infant mortality (r=0.69, p=0.004 for women; r=0.74, p=0.002 for men). Associations between income inequality and mortality declined with age at death, and then reversed among those aged 65 years and older. Income inequality was inconsistently associated with specific causes of death and was not associated with coronary heart disease (CHD), breast or prostate cancer, cirrhosis, or diabetes mortality. Countries that had greater trade union membership and political representation by women had better child mortality profiles. Differences between countries in levels of social capital showed generally weak and somewhat inconsistent associations with cause-specific and age-specific mortality.

INTERPRETATION

Income inequality and characteristics of the psychosocial environment like trust, control, and organisational membership do not seem to be key factors in understanding health differences between these wealthy countries. The associations that do exist are largely limited to child health outcomes and cirrhosis. Explanations for between-country differences in health will require an appreciation of the complex interactions of history, culture, politics, economics, and the status of women and ethnic minorities.

A survey of sports injuries among a convenience sample of Israeli athletes

BACKGROUND

Israel lacks a systematic surveillance of sports injuries, and knowledge of risk factors and specific patterns of injury is inadequate. In order to promote prevention of sports-related injuries, the magnitude of the problem must first be identified and the incidence and severity of sports injuries described.

OBJECTIVE

To conduct a survey on previous sports injuries among a sample of Israeli athletes.

METHODS

A convenience sample of Israeli amateur athletes participating in the 1997 15th Maccabiah Games was randomly selected. The study group answered an anonymous self-administered questionnaire that included sociodemographic data, and information regarding their sports activity and sports-related injuries that had occurred during the previous 2 years.

RESULTS

The study group, aged 12-73 years (median age 21), comprised 301 consenting athletes in 28 different sports. Of these athletes 56.1% reported having had at least one injury. Most injuries (75.6%) involved the upper and lower extremities, and 37.8% of the injured sportsmen had received medical attention from a physician. Half of the athletes participated in contact sports--both collision and limited impact. This group had a much greater proportion of reported injuries in all age groups.

CONCLUSION

Surveillance of sports injuries should be expanded in order to develop appropriate prevention programs in Israel.

Remitting seronegative symmetrical synovitis with pitting edema following intravesical bacillus Calmette-Guérin instillation

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare syndrome of undetermined etiology occurring in the elderly. We describe the first case of RS3PE in a HLA-B27 positive 65-year-old man following intravesical bacillus Calmette-Guérin (BCG) instillation for bladder carcinoma. He developed symmetrical arthritis and synovitis involving wrists, knees, ankles, and metatarsophalangeal joints, with marked pitting edema of the dorsa of both hands and feet, fever, and elevated acute phase reactants. Right knee effusion revealed nonspecific sterile inflammatory fluid. He responded dramatically to nonsteroidal antiinflammatory drugs. BCG instillation may have triggered active symmetrical synovitis via local T cell activation and a T-helper-1 (Th-1)/Th-2 inflammatory profile.

TNF-α Controls Intracellular Mycobacterial Growth by Both Inducible Nitric Oxide Synthase-Dependent and Inducible Nitric Oxide Synthase-Independent Pathways

The role of TNF-alpha in the control of mycobacterial growth in murine macrophages was studied in vitro. Infection of macrophages from TNF-alpha gene disrupted (TNF-knockout (KO)) mice with recombinant Mycobacterium bovis bacillus Calmette Guérin (BCG) expressing the vector only (BCG-vector) resulted in logarithmic growth of the intracellular bacilli. Infection with BCG-secreting murine TNF-alpha (BCG-TNF) led to bacillary killing. Killing of BCG-TNF was associated with rapid accumulation of inducible NO synthase (iNOS) protein and the production of nitrite. The uncontrolled growth of BCG-vector was associated with low iNOS expression but no nitrite production. Thus, iNOS expression appears to be TNF-alpha independent but iNOS generation of NO requires TNF-alpha. In cultures of TNF-KO macrophages infected with BCG-TNF, inhibition of iNOS by aminoguanidine (AMG) abolished the killing of the bacilli. However, the growth of the organisms was still inhibited, suggesting an iNOS-independent TNF-alpha-mediated growth inhibition. To confirm this, macrophages from iNOS-KO mice were infected with either BCG-vector or BCG-TNF. As expected, no nitrite was detected in the culture medium. TNF-alpha was detected only when the cells were infected with BCG-TNF. In the iNOS-KO macrophages, the growth of BCG was inhibited only in the BCG-TNF infection. These results suggest that in the absence of iNOS activity, TNF-alpha stimulates macrophages to control the growth of intracellular BCG. Thus, there appears to be both a TNF-alpha-dependent-iNOS-dependent killing pathway as well as a TNF-alpha-dependent-iNOS-independent growth inhibitory pathway for the control of intracellular mycobacteria in murine macrophages.

Virulence of a Mycobacterium tuberculosis clinical isolate in mice is determined by failure to induce Th1 type immunity and is associated with induction of IFN-alpha /beta

To understand how virulent mycobacteria subvert host immunity and establish disease, we examined the differential response of mice to infection with various human outbreak Mycobacterium tuberculosis clinical isolates. One clinical isolate, HN878, was found to be hypervirulent, as demonstrated by unusually early death of infected immune-competent mice, compared with infection with other clinical isolates. The differential effect on survival required lymphocyte function because severe combined immunodeficiency (SCID) mice infected with HN878 or other clinical isolates all died at the same rate. The hypervirulence of HN878 was associated with failure to induce M. tuberculosis-specific proliferation and IFN-gamma production by spleen and lymph node cells from infected mice. In addition, 2- to 4-fold lower levels of tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-12, and IFN-gamma mRNAs were observed in lungs of HN878-infected mice. IL-10, IL-4, and IL-5 mRNA levels were not significantly elevated in lungs of HN878 infected mice. In contrast, IFN-alpha mRNA levels were significantly higher in lungs of these mice. To further investigate the role of Type 1 IFNs, mice infected with HN878 were treated intranasally with purified IFN-alpha/beta. The treatment resulted in increased lung bacillary loads and even further reduced survival. These results suggest that the hypervirulence of HN878 may be due to failure of this strain to stimulate Th1 type immunity. In addition, the lack of development of Th1 immunity in response to HN878 appears to be associated with increased induction of Type 1 IFNs.

[Traumatic brain injury--the National Trauma Registry]

BACKGROUND

Traumatic Brain Injury (TBI) has been established as a category in reporting systems. Uniform data systems case definition has been suggested for hospital discharge data surveillance systems cases based on ICD-9-CM diagnostic codes. These include fractures and specific mention of intracranial injuries such as contusion, laceration, hemorrhage, and concussion. Inspection of data from the Israel National Trauma Registry suggested that two diagnostic groups of very different severity and outcome were being unjustifiably combined.

AIM

To evaluate the validity of categorizing TBI into two discrete groups, using the presence of specific mention of intracranial injury and/or loss of consciousness for more than one hour as the definition of definite TBI. Possible TBI includes skull fractures with no mention of intracranial injury and/or concussion with no loss of consciousness.

METHODS

The study population includes all traumatic injuries admitted to hospital, dying in the ER or transferred to other hospitals and recorded in the 1998 Trauma Registry in all 6 level I trauma centers in Israel and two level II centers.

RESULTS

The significant difference in severity between groups supports the validity of sub-dividing the TBI classification into definite and possible subcategories. As a result, we obtain two different severity groups without measuring specific severity scores which are limited in the reporting system.

CONCLUSION

The groups were significantly different in severity, hospital resource use, immediate outcome, demographic and injury circumstances.

Acupuncture for osteoarthritis of the knee: a systematic review

OBJECTIVE

To evaluate trials of acupuncture for osteoarthritis (OA) of the knee, to assess the methodologic quality of the trials and determine whether low-quality trials are associated with positive outcomes, to document adverse effects, to identify patient or treatment characteristics associated with positive response, and to identify areas of future research.

METHODS

Eight databases and 62 conference abstract series were searched. Randomized or quasi-randomized trials of all languages were included and evaluated for methodologic quality using the Jadad scale. Outcomes were pain, function, global improvement, and imaging. Data could not be pooled; therefore, a best-evidence synthesis was performed to determine the strength of evidence by control group. The adequacy of the acupuncture procedure was assessed by 2 acupuncturists trained in treating OA and blinded to study results.

RESULTS

Seven trials representing 393 patients with knee OA were identified. For pain and function, there was limited evidence that acupuncture is more effective than being on a waiting list for treatment or having treatment as usual. For pain, there was strong evidence that real acupuncture is more effective than sham acupuncture; however, for function, there was inconclusive evidence that real acupuncture is more effective than sham acupuncture. There was insufficient evidence to determine whether the efficacy of acupuncture is similar to that of other treatments.

CONCLUSION

The existing evidence suggests that acupuncture may play a role in the treatment of knee OA. Future research should define an optimal acupuncture treatment, measure quality of life, and assess acupuncture combined with other modalities.

Systemic inflammatory response with plasma C-reactive protein elevation in disk-related lumbosciatic syndrome

OBJECTIVE

To look for a systemic inflammatory response in patients with disk-related lumbosciatic syndrome by using an ultrasensitive (US) plasma C-reactive protein (CRP) assay, and to determine whether plasma CRP-US levels correlated with clinical and/or laboratory features.

PATIENTS AND METHODS

Plasma CRP was assayed using an enzyme-linked immunosorbent assay (ELISA) (detection limit, 5 microg/L) in patients with sciatica shown by computed tomography to be due to a disk herniation. Levels in 35 patients aged 23 to 64 years were compared to those in age- and sex-matched controls.

RESULTS

Mean CRP-US levels measured by ELISA were significantly higher in the patients than in the controls (1.68 vs 0.74 mg/L; P = 0.002). There was a trend toward higher CRP-US levels in the patients with more severe nerve root symptoms.

CONCLUSION

The significantly higher plasma CRP-US levels by ELISA in our patients with disk-related lumbosciatic syndrome is consistent with a systemic inflammatory response to the local nerve root impingement.

Mycobacterium tuberculosis 19-kilodalton lipoprotein inhibits Mycobacterium smegmatis-induced cytokine production by human macrophages in vitro

Vaccination of mice with Mycobacterium vaccae or M. smegmatis induces some protection against M. tuberculosis challenge. The 19-kDa lipoprotein of M. tuberculosis, expressed in M. vaccae or M. smegmatis (M. smeg19kDa), abrogates this protective immunity. To investigate the mechanism of this suppression of immunity, human monocyte-derived macrophages (MDM) were infected with M. smeg19kDa. Infection resulted in reduced production of tumor necrosis factor alpha (TNF-alpha) (P < 0.01), interleukin-12 (IL-12) (P < 0.05), IL-6 (P < 0.05), and IL-10 (P < 0.05), compared to infection with M. smegmatis vector (M. smegV). Infection with M. smeg19kDa and with M. smegV had no differential effect on expression of costimulatory molecules on MDM, nor did it affect the proliferation of presensitized T cells cocultured with infected MDM. When MDM were infected with M. smegmatis expressing mutated forms of the 19-kDa lipoprotein, including non-O-glycosylated (M. smeg19NOG), nonsecreted (M. smeg19NS), and nonacylated (M. smeg19NA) variants, the reduced production of TNF-alpha or IL-12 was not observed. When the purified 19-kDa lipoprotein was added directly to cultures of infected monocytes, there was little effect on either induction of cytokine production or its inhibition. Thus, the immunosuppressive effect is dependent on glycosylated and acylated 19-kDa lipoprotein present in the phagosome containing the mycobacterium. These results suggest that the diminished protection against challenge with M. tuberculosis seen in mice vaccinated with M. smegmatis expressing the 19-kDa lipoprotein is the result of reduced TNF-alpha and IL-12 production, possibly leading to reduced induction of T-cell activation.

Imide and lactam derivatives of N-benzylpyroglutamyl-L-phenylalanine as VCAM/VLA-4 antagonists

A series of imides and lactams derived from 4-amino-N-benzylpyroglutamyl-L-phenylalanine was prepared and evaluated for activity as VCAM/VLA-4 antagonists. Imides were more potent than the corresponding lactams; several had subnanomolar IC50s in an ELISA based assay and were also highly effective at blocking VLA-4 expressing Ramos cell binding to VCAM coated plates.

Relationship between premature mortality and socioeconomic factors in black and white populations of US metropolitan areas

OBJECTIVE

examined the association of mortality with selected socioeconomic indicators of inequality and segregation among blacks and whites younger than age 65 in 267 US metropolitan areas. The primary aim of the analysis was to operationalize the concept of institutional racism in public health.

METHODS

Socioeconomic indicators were drawn from Census and vital statistics data for 1989-1991 and included median household income; two measures of income inequality; percentage of the population that was black; and a measure of residential segregation.

RESULTS

Age-adjusted premature mortality was 81% higher in blacks than in whites, and median household income was 40% lower. Income inequality, as measured by the Gini coefficient, was greater within the black population (0.45) than within the white population (0.40; p < 0.001). To confirm that the proxy socioeconomic variables were relevant markers of population health status, regression analysis was performed initially on data for the total population. These variables were all independently and significantly related to premature mortality (p < or = 0.01; R(2) = 0.74). Income inequality for the total population was significantly correlated with premature mortality (r = 0.33). Black (r = 0.26) and white (r = 0.20) population-specific correlations between income inequality and premature mortality, while still significant, were smaller. Residential segregation was significantly related to premature mortality and income inequality for blacks (r = 0.38 for both); among whites, however, segregation was modestly correlated with premature mortality (r = 0.19) and uncorrelated with income inequality. Regional analyses demonstrated that the association of segregation with premature mortality was much more pronounced in the South and in areas with larger black populations.

CONCLUSION

Social factors such as income inequality and segregation strongly influence premature mortality in the US. Ecologic studies of the relationships among social factors and population health can measure attributes of the social context that may be relevant for population health, providing the basis for imputing macro-level relationships.

A description of inappropriate hospital stays in selected in-patient services: a study of cases receiving social work services

The number of discharges (63,303) from a university-affiliated medical center in Israel were reviewed. Eight percent of cases in three departments rcceivcd social work services. Patients experiencing inappropriate hospital stay (discharge delay) and who received social work services were characterized and compared with social work clients not experiencing delay. Discharge delay patients differed from other social work clients on key sociodemographic variables. Patients admitted because of "injury" were significantly more likely to experience delay than patients admitted because of "illness." "Waiting for community/institutional resources" was the most common reason for delay and discharge to an institutional setting increased the likelihood of delayed discharge. High risk factors were department-specific and should be studied in context. Results suggested the limited but positive impact of hospital-community collaborative strategies in reducing the incidence of delay over time.

Immunopathologic effects of tumor necrosis factor alpha in murine mycobacterial infection are dose dependent

In experimental mycobacterial infection, tumor necrosis factor alpha (TNF-alpha) is required for control of bacillary growth and the protective granulomatous response, but may cause immunopathology. To directly examine the positive and detrimental effects of this cytokine, a murine model was used in which different amounts of TNF-alpha were delivered to the site of infection. Mice with a disruption in the TNF-alpha gene (TNF-KO) or wild-type mice were infected with low or high doses of recombinant Mycobacterium bovis BCG that secreted murine TNF-alpha (BCG-TNF). Infection of TNF-KO mice with BCG containing the vector (BCG-vector) at a low dose led to increased bacillary load in all organs and an extensive granulomatous response in the lungs and spleen. The mice succumbed to the infection by approximately 40 days. However, when TNF-KO mice were infected with low doses of BCG-TNF, bacillary growth was controlled, granulomas were small and well differentiated, the spleen was not enlarged, and the mice survived. Infection with high inocula of BCG-TNF resulted in bacterial clearance, but was accompanied by severe inflammation in the lungs and spleen and earlier death compared to the results from the mice infected with high inocula of BCG-vector. Wild-type mice controlled infection with either recombinant strain, but showed decreased survival following high-dose BCG-TNF infection. The effects of TNF-alpha required signaling through an intact receptor, since the differential effects were not observed when TNF-alpha receptor-deficient mice were infected. The results suggest that the relative amount of TNF-alpha at the site of infection determines whether the cytokine is protective or destructive.

[Simultaneous onset of rheumatoid polyarthritis and type 1 diabetes]

BACKGROUND

Rheumatoid arthritis and insulin-dependent diabetes mellitus are both autoimmune disorders of unknown etiology. We report the case of a patient who developed the two diseases simultaneously.

CASE REPORT

A 64-year-old man with no remarkable medical history developed insulin-dependent diabetes disclosed by ketoacidosis that occurred 3 weeks after onset of a bilateral symmetrical polyarthritic syndrome characteristic of rheumatoid arthritis.

DISCUSSION

These two disorders share common susceptibility of subjects with MHC class II molecules HLA DRB1*04. Immunological studies have also shown a common Th1 type cytokine-secretion pattern in both diseases. Epidemiological studies have not however clearly demonstrated a link between them.

Immune stimulation in scleroderma patients treated with thalidomide

Scleroderma (SSc) is a fibrosing connective tissue disease that is poorly responsive to any treatment, including immune suppression. SSc shares many characteristics with chronic graft-versus-host disease (GVHD). Because the immunomodulatory drug thalidomide has proven beneficial in chronic GVHD, we studied the immune response and clinical effects of thalidomide in SSc patients. We treated 11 SSc patients with thalidomide in an open label, dose escalating, 12 week study. Histologic comparison of skin biopsies showed changes in skin fibrosis and an increase in epidermal and dermal infiltrating CD8(+) T cells with thalidomide treatment. In thalidomide-treated SSc patients, plasma levels of IL-12 and TNF-alpha increased, while plasma IL-5 and IL-10 levels remained unchanged. These changes were associated with clinical effects, including dry skin, dermal edema, transient rashes, decreased gastroesophageal reflux symptoms, and healing of digital ulcers. When SSc PBMCs activated by anti-CD3 mAb were exposed to thalidomide, increases in both production of IL-2, IL-3, GM-CSF, and IFN-gamma and T cell expression of CD40L were observed. Thalidomide therefore appears to induce immune stimulation in SSc patients in association with clinical changes. However, it remains to be shown whether long-term enhancement of immune responses in SSc patients is clinically beneficial.

Cryptococcal glucuronoxylomannan delays translocation of leukocytes across the blood-brain barrier in an animal model of acute bacterial meningitis

In bacterial meningitis, neurological damage is associated with a high influx of polymorphonuclear leukocytes (PMN) into the brain. Previous data suggest that the capsular component of the fungus C. neoformans, glucuronoxylomannan (GXM), interferes with PMN-migration into the cerebrospinal fluid (CSF). Therefore, a rabbit model of bacterial meningitis was treated intravenously with GXM. This resulted in (1) a reduction of PMN in the CSF at 6 h (P=0.05), (2) reduced peak TNF-alpha concentrations in the CSF, and (3) diminished tissue inflammation and intravascular margination of PMN in GXM-treated animals. Thus, GXM may represent a novel adjuvant anti-inflammatory agent in bacterial meningitis.

Thalidomide for the treatment of AIDS-associated wasting

A double-blind, placebo-controlled trial of efficacy and safety of thalidomide in AIDS-associated wasting was carried out. Ninety-nine of 103 male patients had at least one on-study measurement (intent-to-treat [ITT] cohort). Patients were randomized to thalidomide at 100 mg/day (T100) or 200 mg/day (T200), or placebo for 8 weeks. By ITT analysis, the mean change in body weight of the placebo, T100, and T200 treatment groups was 0.3 kg (0.4%), 2.0 kg (3.0%), and 0.9 kg (1.4%), respectively (p = 0.021 for T100 versus placebo; p = 0.53 for T200 versus placebo). Of the 64 patients who completed the 8 weeks of study treatment, significant weight gain was observed in both the T100 group (2.2 kg, [33%]; p = 0.008 versus placebo) and the T200 group (1.5 kg [2.5%]; p = 0.019 versus placebo). Approximately half the weight gain was fat-free mass (bioimpedance analysis). Patients in the T100 or T200 groups had no significant change in CD4+ cell counts, neutrophil counts, or TNF-alpha levels, compared with placebo. HIV viral load measured as log10 copies/ml decreased by a median of 0.07 in the placebo group, and increased by a median of 0.29 (T100 group) and 0.23 (T200 group) (p = 0.024 andp = 0.018 versus placebo, respectively). Thalidomide therapy was associated with mild to moderate rashes and fevers, but not peripheral neuropathy. Although the anabolic benefits of high-dose thalidomide are limited by drug intolerance, 8 weeks of low-dose thalidomide results in significant weight gain in patients with AIDS-associated wasting.

Staphylococcus aureus RN6390 replicates and induces apoptosis in a pulmonary epithelial cell line

Staphylococcus aureus frequently colonizes the airways of patients with compromised airway defenses (e.g., cystic fibrosis [CF] patients) for extended periods. Persistent and relapsing infections may be related to live S. aureus bacteria actively residing inside epithelial cells. In this study, we infected a respiratory epithelial cell line, which was derived from a CF patient, with S. aureus RN6390. Internalization of S. aureus was found to be time and dose dependent and could be blocked by cytochalasin D. Transmission electron microscopy revealed that internalized bacteria resided within endocytic vacuoles without any evidence of lysosomal fusion in a 24-h period. The results of internalization experiments and time-lapse fluorescence microscopy of epithelial cells infected with green fluorescent S. aureus indicate that, after an initial lag period of 7 to 9 h, intracellular bacteria began to replicate, with three to five divisions in a 24-h period, leading to apoptosis of infected cells. Induction of apoptosis required bacterial internalization and is associated with intracellular replication. The slow and gradual replication of S. aureus inside epithelial cells hints at the role of host factors or signals in bacterial growth and further suggests possible cross talk between host cells and S. aureus.

Aerosol infection of mice with recombinant BCG secreting murine IFN-gamma partially reconstitutes local protective immunity

To better understand the contribution of interferon-gamma (IFN-gamma) to the immune response during the first 60 days of mycobacterial infection in the lungs, IFN-gamma gene disrupted (IFN-gamma-/-) mice were infected via aerosol with recombinant Mycobacterium bovis Bacillus Calmette-Guerin (BCG) secreting murine IFN-gamma (BCG-IFN-gamma) and compared to mice infected with recombinant BCG containing the vector only (BCG-vector). When IFN-gamma-/- mice were infected with BCG-vector, increasing bacillary loads and large undifferentiated granulomas that did not express inducible nitric oxide synthase (iNOS) were observed in the lungs. In contrast, infection with BCG-IFN-gamma resulted in reduced bacillary load and better differentiated granulomas containing epithelioid macrophages expressing iNOS as well as reduced levels of interleukin 10 (IL-10) mRNA. However, local production of IFN-gamma by the recombinant BCG did not protect IFN-gamma-/- mice from subsequent challenge with M. tuberculosis. Infection of IFN-gamma-/- peritoneal macrophages in vitro with BCG-IFN-gamma led to induction of iNOS expression and lower IL-10 mRNA levels. Nevertheless, the growth of the intracellular BCG was unaffected. Since IFN-gamma induced-iNOS protein and reduced IL-10 production were insufficient to control mycobacterial growth in vitro, the results suggest that additional mediator(s) present in vivo are required for control of mycobacterial growth.

Modulation of hyperoxia-induced TNF-alpha expression in the newborn rat lung by thalidomide and dexamethasone

The effect of high oxygen concentrations on lungs of neonatal rats was studied. In addition, some oxygen-exposed animals were treated with either dexamethasone or thalidomide. No gross histologic changes were noted in the lungs following exposure to 95% oxygen nor were there changes in the total number or the phenotypic distribution of BAL cells obtained from these lungs compared to lungs from air exposed (control) neonatal rats. The majority of the BAL cells were CD45+ leukocytes (macrophages). However, when BAL cells were exposed to LPS in vitro, TNF-alpha production was higher in cells from rats exposed to 95% oxygen compared to cells from rats exposed to ambient air. In addition, lung TNF-alpha and IL-6 mRNA levels were increased after exposure to 95% oxygen. In the lungs of animals treated with either dexamethasone or thalidomide, TNF-alpha mRNA levels were reduced, while only dexamethasone treatment also reduced IL-6 mRNA levels.