Effects of different tuberculin skin-testing regimens on gamma interferon and antibody responses in cattle experimentally infected with Mycobacterium bovis

Although tuberculin skin testing has been a hallmark of bovine tuberculosis eradication campaigns, it lacks sensitivity, can be confounded by exposure to nontuberculous mycobacteria, and cannot be repeated for 60 days due to desensitization. To overcome these difficulties, an effective whole-blood cellular immunoassay for bovine gamma interferon (IFN-gamma) has been developed. The IFN-gamma test is commonly used in conjunction with tuberculin skin testing as a confirmatory test following a positive response to the caudal fold test (CFT). The present study was conducted to determine the effect of different tuberculin skin-testing regimens on IFN-gamma and antibody production by using calves that were experimentally infected with Mycobacterium bovis. Holstein calves were CFT tested 60 days after inoculation and the comparative cervical test (CCT) was conducted 7 (7-day CCT) or 55 (55-day CCT) days after the CFT. In both the 7-day CCT and 55-day CCT groups, IFN-gamma responses increased 3 days after the CFT; this was immediately followed by a decrease to pre-skin test levels 7 days after the CFT. In both groups, the application of the CCT at 7 or 55 days after the CFT resulted in no significant increase in IFN-gamma production. The administration of the CFT and the CCT to M. bovis-inoculated cattle boosted antibody responses to M. bovis PPD, rMPB83, ESAT-6, and the fusion protein Acr1-MPB83. The boosting effect was more pronounced in the 55-day CCT group. Increases in either IFN-gamma or antibody production were not seen in noninoculated cattle. Measurement of both IFN-gamma and antibody responses after skin testing may be useful in identifying M. bovis-infected cattle; however, the timing of collection of such samples may influence interpretation.

Antibody responses in reindeer (Rangifer tarandus) infected with Mycobacterium bovis

Despite having a very low incidence of disease, reindeer (Rangifer tarandus) are subject to tuberculosis (TB) testing requirements for interstate shipment and herd accreditation in the United States. Improved TB tests are desperately needed, as many reindeer are falsely classified as reactors by current testing procedures. Sera collected sequentially from 11 (experimentally) Mycobacterium bovis-infected reindeer and 4 noninfected reindeer were evaluated by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and multiantigen print immunoassay (MAPIA) for antibody specific to M. bovis antigens. Specific antibody was detected as early as 4 weeks after challenge with M. bovis. By MAPIA, sera were tested with 12 native and recombinant antigens, which were used to coat nitrocellulose. All M. bovis-infected reindeer developed responses to MPB83 and a fusion protein, Acr1/MPB83, and 9/11 had responses to MPB70. Other antigens less commonly recognized included MPB59, ESAT-6, and CFP10. Administration of purified protein derivatives for skin testing boosted serum antibody responses, as detected by each of the assays. Of the noninfected reindeer, 2/4 had responses that were detectable immediately following skin testing, which correlated with pathological findings (i.e., presence of granulomatous lesions yet the absence of acid-fast bacteria). The levels of specific antibody produced by infected reindeer appeared to be associated with disease progression but not with cell-mediated immunity. These findings indicate that M. bovis infection of reindeer elicits an antibody response to multiple antigens that can be boosted by skin testing. Serological tests using carefully selected specific antigens have potential for early detection of infections in reindeer.

Antigen recognition by serum antibodies in white-tailed deer (Odocoileus virginianus) experimentally infected with Mycobacterium bovis

White-tailed deer (Odocoileus virginianus) have emerged as reservoirs of bovine tuberculosis in northern America. For tuberculosis surveillance of deer, antibody-based assays are particularly attractive because deer are handled only once and immediate processing of the sample is not required. Sera collected sequentially from 25 Mycobacterium bovis-infected and 7 noninfected deer were evaluated by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and multiantigen print immunoassay (MAPIA) for immunoglobulin specific to M. bovis antigens. Various routes of experimental M. bovis infection, such as intratonsillar inoculation (n = 11), aerosol (n = 6), and exposure to infected deer (in contact, n = 8), were studied. Upon infection, specific bands of reactivity at approximately 24 to 26 kDa, approximately 33 kDa, approximately 42 kDa, and approximately 75 kDa to M. bovis whole-cell sonicate were detected by immunoblot. Lipoarabinomannan-specific immunoglobulin was detected as early as 36 days postchallenge, and responses were detected for 94% of intratonsillarly and "in-contact"-infected deer. In MAPIA, sera were tested with 12 native and recombinant antigens coated on nitrocellulose. All in-contact-infected (8 of 8) and 10 of 11 intratonsillarly infected deer produced antibody reactive with one or more of the recombinant/native antigens. Responses were boosted by injection of tuberculin for intradermal tuberculin skin testing. Additionally, three of six deer receiving a very low dose of M. bovis via aerosol exposure produced antibody specific to one or more recombinant proteins. M. bovis was isolated from one of three nonresponding aerosol-challenged deer. Of the 12 antigens tested, the most immunodominant protein was MPB83; however, a highly sensitive serodiagnostic test will likely require use of multiple antigens.

Lack of effect of doxycycline on disease activity and joint damage in patients with rheumatoid arthritis. A double blind, placebo controlled trial

OBJECTIVE

To investigate the effects of doxycycline on disease activity and joint destruction in patients with rheumatoid arthritis (RA).

METHODS

A 36 week double blind, placebo controlled crossover trial was conducted. Patients (n = 66) received 50 mg doxycycline or placebo twice a day during 12, 24, or 36 weeks. Patient assessments were performed before the treatment was administered, at 6, 12, 24 and 36 weeks of treatment, and finally at 4 weeks after cessation of treatment. Patient assessments, swollen and tender joint counts, duration of morning stiffness, erythrocyte sedimentation rate, and Modified Disease Activity Score were used as measures of disease activity. Effects on joint destruction were assessed by urinary excretion of the pyridinolines hydroxylysylpyridinoline and lysylpyridinoline and by scoring radiographic damage of hands and feet before and after treatment.

RESULTS

The changes of clinical or laboratory disease activity measures, pyridinoline excretion, or progression of radiographic joint damage during doxycycline or placebo treatment did not differ significantly.

CONCLUSION

The results indicate that 50 mg doxycycline twice a day provided no therapeutic benefit for patients with RA.

Biologic properties of non-antibiotic, chemically modified tetracyclines (CMTs): a structured, annotated bibliography

The first paper reporting on a potentially important medical property of a non-antimicrobial tetracycline appeared in 1987. Since then, a literature of over 75 papers has supported the therapeutic potential of this class of compounds. In this review, this literature is grouped and organized with commentary on the data which has been published to date. The biomedical applicability of these discoveries obviously covers a wide range of medical conditions and clearly justifies their continued development.

Effect of age on interaural asymmetry of event-related potentials in a dichotic listening task

Three groups of subjects, children, young adults, and elderly persons with presbyacusis, were tested in a directed attention, quasidichotic paradigm in which continuous speech was monitored for syntactically and/or semantically anomalous words. The task evoked an event-related potential (ERP) characterized by a positive peak in the latency region of 600 to 1,000 msec. ERPs were separately averaged for target-word-right and target-word-left conditions. Amplitude and latency measures at the peak of the global field power waveform were calculated. Amplitude was significantly larger in children than in either adult group. In children and young adults, both amplitude and latency measures were equivalent for target-right and target-left conditions, but in elderly persons, latency was significantly greater in the target-left than in the target-right condition. Topographic maps of amplitude at the peak of the ERP waveform showed maximal positivity symmetrically distributed around the midline centroparietal area in both right-attended and left-attended conditions. In elderly persons, however, maximal positivity in the left-attended condition was significantly delayed relative to maximal positivity in the right-attended condition. Results are consistent with previous findings of interaural asymmetry in a dichotic listening task in elderly persons.

Toward a more ecologically valid measure of speech understanding in background noise

In an attempt to develop a more ecologically valid measure of speech understanding in a background of competing speech, we constructed a quasidichotic procedure based on the monitoring of continuous speech from loudspeakers placed directly to the listener's right and left sides. The listener responded to the presence of incongruous or anomalous words imbedded within the context of two children's fairy tales. Attention was directed either to the right or to the left side in blocks of 25 utterances. Within each block, there were target (anomalous) and nontarget (nonanomalous) words. Responses to target words were analyzed separately for attend-right and attend-left conditions. Our purpose was twofold: (1) to evaluate the feasibility of such an approach for obtaining electrophysiologic performance measures in the sound field and (2) to gather normative interaural symmetry data for the new technique in young adults with normal hearing. Event-related potentials to target and nontarget words at 30 electrode sites were obtained in 20 right-handed young adults with normal hearing. Waveforms and associated topographic maps were characterized by a slight negativity in the region of 400 msec (N400) and robust positivity in the region of 900 msec (P900). Norms for interaural symmetry of the P900 event-related potential in young adults were derived.

The power of suggestion: comment on EMDR and mesmerism: a comparative historical analysis

This response to McNally challenges the notion that scientific controversy should be waged with smear tactics. McNally's anti-EMDR conclusions are contested as premature and based on red herrings, selective neglect of the literature, and erroneous application of scientific principles. The importance of treatment fidelity is highlighted as a way of distinguishing between EMDR studies of widely varying quality.

The potential role of doxycycline in the treatment of osteoarthritis of the temporomandibular joint

Collagenase and gelatinase are matrix metalloproteinases (MMPs) which play an important role in tissue destruction in arthritic joints. Studies have demonstrated that tetracyclines can inhibit MMPs and prevent tissue destruction independent of their antimicrobial activity. The purpose of this pilot study is to assess the potential therapeutic role of Doxycycline in patients with advanced osteoarthritis of the temporomandibular joint (TMJ). This ongoing investigation includes patients with a diagnosis of osteoarthritis of the TMJ based on clinical and diagnostic imaging findings, symptoms (localized TMJ pain, limited mobility, dysfunction) for a minimum of 36 months, and failure of previous non-surgical and surgical modalities to alleviate the symptoms. A synovial fluid sample is collected by a saline injection and aspiration technique, followed by diagnostic arthroscopy. Patients are placed on Doxycycline 50 mg BID for three months and then undergo repeat diagnostic arthroscopy and synovial fluid collection. The samples are stored at -80 degrees C. Collagenase activity is determined by a combination of SDS-polyacrylamide gel electrophoresis and fluorography and calculated based on the percentage of collagen alpha chains that are degraded into alphaA breakdown products. Three patients have completed the three-month course of Doxycycline thus far, and 5 joints with osteoarthritis have been analyzed. All patients were female (mean age = 35, mean duration of symptoms = 132 months) and had undergone previous bilateral arthroscopies. One patient had undergone unilateral arthroplasty. The mean collagenase activity showed 55% collagen lysis prior to Doxycycline treatment and 19% after three months of therapy. The mean gelatinase activity was 28% prior to Doxycycline treatment and 7% after three months of therapy. The mean interincisal opening was 33 mm initially and 41 mm after three months of Doxycycline. Subjectively, two of the three patients reported significant improvement in their overall symptoms, which they had not experienced over the previous three years. One patient did not experience any change in symptoms, in spite of a marked reduction in collagenase activity from 86.4% to 9.6%. Because of the very small numbers of patients enrolled in this pilot study so far, no statistically significant differences could be appreciated. However, the dramatic reduction in collagenase activity in these patients, with a long history of TMJ symptoms from osteoarthritis, suggests the potential promising role of Doxycycline in the management of osteoarthritis, and further investigation is warranted.

The function of costimulatory molecules and the development of IL-4-producing T cells

The development of IL-4-producing effector T cells during a type 2 immune response requires signaling through B7 ligands, but probably not CD40 ligands. Here, William Gause and colleagues review the still controversial role of CD28 and CTLA-4 on T cells, and B7-1 and B7-2 on antigen-presenting cells, and provide a model to incorporate recent findings.

Chemically modified tetracyclines inhibit inducible nitric oxide synthase expression and nitric oxide production in cultured rat mesangial cells

Tetracyclines inhibit matrix metalloproteinases (MMP) and attenuate connective tissue degradation in a wide variety of human and animal disorders. Chemically modified tetracyclines (CMT) have been synthesized in which the antibacterial potency has been eliminated but in which the anti-MMP efficacy is retained. Nitric oxide (NO) modulates MMP synthesis and activity in mesangial cells in vitro. Therefore, we examined whether CMT inhibit iNOS gene and protein expression and NO production in cultured rat mesangial cells. Mesangial cells were maintained in media containing IFN-gamma and LPS for 24-72 h. Test media contained either no further additives or CMT-1, 3, 5, or 8 at concentrations of 1, 2.5, 5, and 10 micrograms/ml. iNOS gene and protein expression were assessed and NO production was determined by the Griess reaction. Incubation of mesangial cells with CMT-3 and CMT-8 resulted in time- and dose-dependent inhibition of NO production that was maximal at 48 h (< 20% of control) and at a drug concentration of 5 micrograms/ml (P < 0.05). Addition of CMT-1 had a modest (40%) inhibitory effect and CMT-5 did not alter NO production. The impact of CMT on NO production was directly related to their potency as collagenase inhibitors. Moreover, CMT-induced changes in NO synthesis were associated with parallel alterations in steady-state iNOS mRNA abundance and protein expression. These agents may be useful to ameliorate NO-dependent glomerular inflammation.

The handling of corneal donor tissue before penetrating keratoplasty

1. Corneal tissue must meet quality standards established by Federal Regulations and state laws. 2. Documented information regarding eye bank tissue is privileged and confidential. 3. Media used to store corneal tissue must meet Food and Drug Administration (FDA) Good Manufacturing Practices standards.

The handling of corneal donor tissue before penetrating keratoplasty

1. Corneal tissue must meet quality standards established by Federal Regulations and state laws. 2. Documented information regarding eye bank tissue is privileged and confidential. 3. Media used to store corneal tissue must meet Food and Drug Administration (FDA) Good Manufacturing Practices standards.

Meprin activity in rats with experimental renal disease

Activity of renal meprin, a membrane-bound proteinase in the proximal tubule brush border, was measured in normal rats and in two disease groups: chronic puromycin aminonucleoside nephropathy for 12 weeks and streptozocin-induced diabetes for 6 months. Enzyme activity in kidney homogenates was assayed using azocasein as substrate. The mean activity of mephrin was 3.22 +/- 0.34 U/g kidney weight in normal rats. In diabetic animals, enzyme activity was 8.58 +/- 2.11 U/g kidney weight, P < 0.01. In contrast, meprin activity was decreased in rats with puromycin-induced glomerulopathy, 2.13 +/- 0.17 U/g kidney weight, P < 0.01. These findings indicate that meprin activity is elevated in experimental diabetes. Diminished activity of this luminal membrane enzyme in puromycin aminonucleoside nephropathy may contribute to renal injury in this disease model associated with massive urinary protein excretion.

Scleroderma-like fasciitis without eosinophilia after L-tryptophan ingestion

A 53-year-old man developed severe sclerodermatous skin changes and a neuromyopathic process, consistent with the eosinophilia-myalgia syndrome, 2 months after discontinuation of L-Tryptophan (L-Try). His peripheral eosinophil count was within normal limits upon presentation and remained so throughout the illness. Currently the Centers for Disease Control surveillance definition requires peripheral eosinophilia greater than 1000 cells/mm3. Eosinophilia-myalgia syndrome may need to be part of a differential diagnosis even in the absence of peripheral eosinophilia.

Delayed postbacteremic prosthetic joint infection

Deep infection of a prosthetic joint is a devastating complication. One proposed mechanism of late prosthetic joint infection involves hematogenous spread from an extraarticular focus of infection. Two cases clearly demonstrate hematogenously acquired prosthetic joint infections, one caused by Clostridium perfringens and the other by Streptococcus pneumoniae. These cases were unusual in that a long asymptomatic period intervened between the primary bacteremic illness and the subsequent prosthetic infection. Patients with prosthetic joints who develop bacteremic infection at extraarticular sites should be treated promptly and aggressively with appropriate antibiotics. Prophylactic antibiotics should be strongly considered in the patient with a prosthetic joint who undergoes procedures likely to be associated with a bacteremia. Transient arthralgias at the time of bacteremia may represent the onset of the joint infection and should not be overlooked or attributed a priori to the patient's underlying arthritic or medical condition.