Soluble mediators of articular cartilage degradation in juvenile rheumatoid arthritis

Juvenile rheumatoid arthritis (JRA) involves a wide range of joint tissues. Tissue changes include proliferation of synovial cells, alterations in synovial fluid, and degradation of articular cartilage. Synovial cell proliferation results in increased numbers of fibroblasts and lymphocytes. Changes in the synovial fluid include increased content of antibodies, altered complement ratios, increased levels of factors stimulating cartilage-mediated proteoglycan degradation, and decreased levels of insulinlike growth factor I. Levels of cytokine such as interleukin-1 and interleukin-2 vary with cell culture and assay technique. Cartilage degradation is apparent from increased quantities of proteoglycan and glycosaminoglycan in serum and synovial fluid. Type II collagen peptide antibodies are also prevalent in JRA patients. Cartilage degradation appears linked to factors in JRA synovial fluid. Conditioned medium of peripheral blood mononuclear cells from patients with JRA also stimulates increased release of cartilage proteoglycan. Thus, the outcome in JRA likely reflects activities of interacting soluble factors that directly influence cartilage homeostasis.

Glucosaminidase, galactosaminidase, and glucuronidase in the growth plate

The activities of glucosaminidase, galactosaminidase, and glucuronidase were determined in fractions of bovine growth plate cartilage. Glucosaminidase and galactosaminidase activities were lowest in the area corresponding to the reserve cartilage and increased from the upper to the lower portions of the hypertrophic zones of the growth plate, reaching a maximum in the calcifying cartilage. Glucuronidase activity showed a distinct spike of activity in the calcifying cartilage. The spatial distribution of these activities suggests a role in calcification and in the dissolution of the extracellular matrix at the chondro-osseous junction of the growth plate.

Adaptation of brain 5HT2 receptors after mianserin treatment: receptor sensitivity, not receptor binding, more accurately correlates with behavior

This study investigates the possibility that mianserin, a serotonin-2 (5HT2) receptor antagonist, produces a prolonged antagonism of quipazine discrimination, consistent with its prolonged biochemical effects. Rats were trained on a saline-quipazine (1.5 mg/kg) discrimination; following acquisition, the animals were assigned to groups and given injections of 2.0 mg/kg mianserin. Individual groups were tested at 45 min and successive 12-hr intervals for their ability to discriminate 0.75 mg/kg of quipazine, a dose that elicited 75% responding on the quipazine lever. Blockade of the quipazine cue persisted for 48 hr following mianserin administration. The above procedure was replicated using lower doses of mianserin (0.25, 0.10 and 0.05 mg/kg) and two other 5HT2 antagonists, pizotifen and metergoline (2.0 mg/kg), both of which showed similar profiles of extended antagonism. Changes in both receptor density and receptor sensitivity were investigated as possible mechanisms of mianserin's prolonged activity. Analysis of [3H]ketanserin binding revealed that a single 2.0-mg/kg dose of mianserin produced a significant decrease in the number of receptor sites (44%) 24 hr after treatment; however, this loss of sites recovered by 36 hr post-injection and could therefore not account for mianserin's continued antagonism at this and later times. 5HT-mediated phosphoinositide hydrolysis in cerebral cortex slices was used as a measure of 5HT2 receptor sensitivity. Treatment of rats with 2 mg/kg of mianserin caused a marked reduction in the maximum phosphoinositide response to 5HT that persisted for up to 36 hr. Hence, the time course for recovery of 5HT2 receptor sensitivity corresponded more closely to behavioral recovery than did 5HT2 receptor binding.

Mitochondrial DNA variation in long-term tissue cultured rice lines

The effects of long-term tissue culture on mitochondrial DNAs were examined using rice (Oryza sativa) cell suspension cultures. Mitochondrial DNAs were isolated from P. I. 353705 (an indica subspecies of rice similar to 'Asam 5'), its anther-culture-derived line BL2 (an 8-year-old cell suspension culture), and five other cell lines (A1, A7, A11, A13, and A23), also derived from BL2 and independently selected for resistance to the lysine analog, S-(2-amino)-ethyl-L-cysteine. Mitochondrial DNAs of the rice lines were digested with ten restriction endonucleases (BamHI, BglII, EcoRI, EcoRV, HindIII, PstI, PvuII, SalI, SmaI, and XhoI), electrophoresed, and transferred to nylon membranes. Southern blots were hybridized with one rice and five maize probes containing mitochondrial genes. The restriction patterns of ten Southern blots and hybridization patterns of 60 endonuclease/probe combinations were analyzed. DNAs from all sources produced unique restriction patterns when digested with HindIII or BglII; with the other endonucleases an array of similarities and differences was observed. Lines BL2 and A11 showed unique patterns with all restriction endonucleases tested. No hybridization pattern differences were observed among the lines when probes containing apt9 and atpA were used. However, extensive hybridization pattern differences were observed with coxI, coxII, rrn18-rrn5, and atp6 probes. Both restriction and hybridization patterns revealed variation due to tissue culture effect. Coxll was most efficient in revealing the uniqueness of BL2. Among the analog selected lines A11 was most divergent, and probes rrn18-rrn5 and atp6 were most efficient in revealing its distinctiveness. Unique mitochondrial genomic organizations were found to be associated with long-term tissue culture.

Control of nitrogenase recovery from oxygen inactivation by ammonia in the cyanobacterium Anabaena sp. strain CA (ATCC 33047)

The control of nitrogenase recovery from inactivation by oxygen was studied in Anabaena sp. strain CA (ATCC 33047). Nitrogenase activity (acetylene reduction) in cultures grown in 1% CO2 in air was inhibited by exposure to 1% CO2-99% O2 and allowed to recover in the presence of high oxygen tensions. Cultures exposed to hyperbaric levels of oxygen in the presence of 10 mM NH4NO3 were incapable of regaining nitrogenase activity, whereas control cultures returned to 65 to 80% of their original activity within about 3 h after exposure to high oxygen tension. In contrast to the regulation of heterocyst differentiation and nitrogenase synthesis, recovery from oxygen inactivation in this organism was shown to be under the control of NH4+ rather than NO3-.

Quantitation and relative distribution of extracellular matrix in Staphylococcus epidermidis biofilm

The relationship between adherence of bacteria to foreign bodies and their deposition of extracellular matrix was examined on glass and suture material. To quantitate bacterial adherence, uptake of [3H]thymidine into bacterial DNA was analyzed. Corresponding amounts of extracellular matrix were measured by a new technique using [14C]glucose incorporation. This study shows that [14C]glucose preferentially labeled bacterial strains in proportion to biofilm production. The ratio of 3H14C in high biofilm producers was 0.9 and in low producers it was 3.7. Radioactive identification of organisms as high and low producers was confirmed by electron microscopy. The results presented here show that production and accumulation of biofilm over time is a stable characteristic in different strains of S. epidermidis. The use of ratios reflecting radiolabeling of bacteria and biofilm by [3H]thymidine and [14C]glucose, respectively, is a quantitative yet simple technique to assess extracellular matrix of different strains of S. epidermidis.

Nerve growth factor-dependence of herpes simplex virus latency in peripheral sympathetic and sensory neurons in vitro

Previously, we reported that nerve growth factor (NGF) is required to maintain herpes simplex virus (HSV) latency in cultures of rat sympathetic neurons (Wilcox and Johnson, 1987, 1988). Here, we extend these results by showing that NGF was also required to maintain HSV latency in cultures of sensory neurons obtained from dorsal root ganglia of rats, monkeys, and humans. The interruption of the neuronal supply of NGF for 1 hr reactivated HSV, indicating that the latent virus was exquisitely sensitive to perturbations in the concentration or binding of NGF. A species-specific monoclonal antibody directed against the human NGF-receptor, which blocks NGF binding, reactivated latent HSV in human, but not rat, sensory neurons. In contrast, a monoclonal antibody against the rat NGF-receptor, which binds the receptor without blocking NGF action, did not produce reactivation. These results indicate that the effects of NGF on HSV latency are mediated via NGF binding to the NGF receptor. In addition, treatments that interfere with specific steps in the transduction of the NGF signal, including treatment with 6-hydroxydopamine and colchicine, reactivated latent HSV. Further, in neurons harboring latent virus, interruption of protein synthesis or RNA transcription for 1 hr resulted in viral reactivation, suggesting that a short-lived factor may be present in neurons which represses viral reactivation.

Septic arthritis. Staphylococcal induction of chondrocyte proteolytic activity

We report herein that cartilage proteolytic activity increased in bovine and rabbit articular cartilage after treatment with a purified staphylococcal culture medium or intraarticular infection with Staphylococcus aureus. Staphylococcal culture medium increased the release of gelatinolytic, collagenolytic, and caseinolytic activity into the medium of isolated chondrocytes or cartilage organ culture. The proteolytic activities were determined in assays using radiolabeled substrate and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Staphylococcal culture medium was proteolytically inactive by both assay techniques. RNA synthesis of isolated chondrocytes was unaffected by staphylococcal culture medium, whereas overall protein synthesis was inhibited by 84%. An analysis of extracts of Staphylococcus aureus-infected rabbit knee cartilage by substrate gels showed increased gelatinolytic and caseinolytic activity compared with extracts of uninfected knee cartilage. Our data suggest that the rapid loss of proteoglycan and persistent degradation of cartilage in staphylococcal septic arthritis is due to the production and activation of chondrocyte proteases.

Stimulation of adult chondrocyte metabolism by a thyroid-derived factor

This paper reports the effects of adding partially purified bovine thyroid calcitonin, thyrocalcitonin, to adult bovine articular cartilage cells. Thyrocalcitonin stimulated chondrocyte proliferation fourfold under low serum (0.5%) culture conditions. In serum-free medium, thyrocalcitonin stimulated cell proliferation more than twofold. With high-density cultures in serum-free medium, chondrocyte glycosaminoglycan (GAG) synthesis was stimulated 60% by thyrocalcitonin. Cell-associated radioactivity was increased twofold. In contrast to thyrocalcitonin, addition of human and salmon calcitonin peptides as well as the thyroid hormones T3 and T4 had no effect on adult cartilage cell proliferation or GAG synthesis. The data reported here suggest the existence of a thyroid-derived factor, independent of calcitonin peptides or thyroid hormones, which stimulates adult articular chondrocyte metabolism.

Encoding of amplitude modulation in the gerbil cochlear nucleus: II. Possible neural mechanisms

Rapid changes in sound amplitude--amplitude modulation (AM)--comprise an important feature of biologically-relevant sounds, including speech. In the companion paper, a hierarchy of enhancement for AM processing was demonstrated for unit types of the gerbil ventral cochlear nucleus (VCN) [Frisina, et al., Hear. Res. 44, 1990]. In the present report additional neurophysiological findings are presented as an initial test of alternative hypotheses of how VCN unit types amplify or enhance AM information, and how they accomplish this over a wide intensity range. These hypotheses invoke mechanisms such as off-CF excitatory or inhibitory inputs, input from high-threshold auditory-nerve fibers, amplification of residual AM responses of auditory-nerve fibers at high intensities, or post-synaptic cell feedback. From consideration of VCN unit response properties such as onset and steady-state rate-intensity functions, pure-tone tuning, and non-CF responses to AM, it is concluded that: Off-CF excitatory inputs do not play a significant role in VCN AM encoding; Off-CF inhibitory inputs could work in conjunction with one or more of the other proposed mechanisms to account for differential enhancement of AM by VCN neurons.

Encoding of amplitude modulation in the gerbil cochlear nucleus: I. A hierarchy of enhancement

The main goal of the present study was to investigate the encoding of a biologically-relevant acoustic feature--amplitude modulation (AM)--in single neurons of the auditory nerve and ventral cochlear nucleus (VCN). In the anesthetized gerbil auditory-nerve fibers and VCN units show strong synchronous responses to low-intensity, low-frequency AM. As frequency increases, the strength of the synchronous response decreases. In the auditory nerve the strength of the synchronous response is substantially less at high intensities than at low intensities and does not change significantly with AM frequency at high intensities. In contrast to the auditory nerve, VCN units show strong responses at high intensities. They have a particular AM frequency to which they are maximally responsive, and this frequency varies from unit to unit. Therefore, VCN units transform their ascending inputs by enhancing the synchronous response to AM. A correlation exists between a unit's ability to encode AM and its responses to simple sounds. Specifically, onset units show the strongest synchronous responses, followed in order by chopper, primarylike-with-notch and primarylike units. This enhancement is greatest at high intensities and can occur up to 90 dB above a unit's threshold. Thus, a hierarchy of enhancement for AM processing exists in the most peripheral nucleus of the central auditory system.

Phosphorylase kinase isozymes and phosphorylase in denervated skeletal muscles

The effects of motor denervation on levels of phosphorylase kinase isozymes and phosphorylase were investigated in rat epitrochlearis, hemidiaphragm, and soleus muscles. Amounts of the proteins were measured after quantitative immunoprecipitation and found to be decreased by as much as 70% 2 weeks after denervation. Unexpectedly, denervation had little, if any, effect on the relative proportions of the two phosphorylase kinase isozymes. Phosphorylase and phosphorylase kinase were decreased by essentially the same extent after denervation, and the effects of denervation were comparable in all three muscles. The decreases in these enzymes explain, at least in part, the marked alterations in glycogen metabolism that occur after motor denervation.

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors. 6. Trans-6-[2-(substituted-1-naphthyl)ethyl(or ethenyl)]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-ones

A variety of trans-6-[2-(substituted-1-naphthyl)ethyl(or ethenyl)]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-ones were prepared and, upon conversion to their 3,5-dihydroxy carboxylates, were found to have good inhibitory activity against the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the rate-determining enzyme in cholesterogenesis. The most active compounds are 2,4,6- and 2,4,7-trichloro derivatives and would be expected to display about the same potency as the standard compactin upon resolution.

Topically active carbonic anhydrase inhibitors. 3. Benzofuran- and indole-2-sulfonamides

Derivatives of benzofuran- and indole-2-sulfonamide were prepared for evaluation as topically active ocular hypotensive agents. These compounds were found to be excellent inhibitors of carbonic anhydrase and to lower intraocular pressure in a rabbit model of ocular hypertension. However, the development of these compounds for clinical use was precluded by the observation that they cause dermal sensitization in guinea pigs. A correlation between electrophilicity, as assessed by in vitro reactivity with reduced glutathione, and dermal sensitization potential was further documented.

L-662,583 is a topically effective ocular hypotensive carbonic anhydrase inhibitor in experimental animals

1. L-662,583 was a potent inhibitor in vitro of purified, human erythrocyte carbonic anhydrase II, possessing an IC50 of 0.7 nM. The IC50 values for MK-927, acetazolamide and methazolamide were 13.0 nM, 10.8 nM and 21.2 nM, respectively. 2. A 1 h pretreatment with one 50 microliters drop of a 0.1% solution of L-662,583 blocked carbonic anhydrase activity in a homogenate of the iris + ciliary body of albino rabbits by 63%. Similar treatment with 0.1% suspensions of acetazolamide and methazolamide elicited inhibitions of 30% and 20%, respectively. This ex vivo model indirectly assesses the ability of an agent to enter the rabbit eye. 3. Concentrations of L-662,583 in the cornea, aqueous humour and iris + ciliary body of albino rabbits were determined by h.p.l.c. at predetermined times after the instillation (one drop of 50 microliters) of a 2% solution of L-662,583. Peak levels for cornea (47.4 micrograms g-1), aqueous humour (4.51 micrograms ml-1) and iris + ciliary body (9.61 micrograms g-1) occurred at 0.5, 2 and 1 h after instillation, respectively. 4. The experimentally elevated intraocular pressure of the right eye of rabbits, induced by prior intraocular injection of alpha-chymotrypsin, was maximally decreased by 4.5 mmHg, 6.2 mmHg and 9.8 mmHg after the instillation (one drop of 50 microliters) of 0.01%, 0.1% and 0.5% solutions of L-662,583, respectively. All three concentrations lowered intraocular pressure at all time points from 1 h up to and including 5 h, the last recorded time point. The unilateral instillation of L-662,583 (0.5%) into the contralateral, left eye failed to lower the elevated intraocular pressure of the untreated, right eye. This finding indicates that the site of action of topically applied L-662,583 in this paradigm is local. The ocular normotensive, albino rabbit was much less susceptible than the ocular hypertensive rabbit to the intraocular pressure lowering effect of topically applied L-662,583, with a 2% solution maximally decreasing intraocular pressure by 2.3 mmHg. 5. Unilateral ocular hypertension was elicited in the right eye of sedated, cynomolgus monkeys by argon laser-induced photocoagulation of the trabecular meshwork. The instillation (one drop of 50 microL) of L-662, 583 (2%) significantly lowered the elevated intraocular pressure of the right eye at all time points from 1 h up to and including 5 h. The maximum decline was 8.3 mmHg at 3 h and this represented a reduction of 23% from the corresponding baseline value of 36.8 mmHg. The intraocular pressure of the hypertensive, right eye was maximally decreased by 4.1 mmHg and 4.8 mmHg after the instillation of 0.5% and 1% solutions of L-662,583, respectively. Like the rabbit, the normotensive eye of cynomolgus monkeys was more resistant than the hypertensive eye to the ocular hypotensive action of L-662, 583, as indicated by the inability of 0.5% and 1% solutions of the agent to lower intraocular pressure. L-662,583 (2%) maximally reduced the intraocular pressure of normotensive monkey eyes by 2.4 mmHg at 2 h. 6. L-662,583 is structurally different from MK-927, a carbonic anhydrase inhibitor that lowers the intraocular pressure of glaucoma patients following the instillation of a 2% solution. These preclinical observations indicate that L-662,583, like MK-927, is a water-soluble carbonic anhydrase inhibitor which, on topical administration, lowers intraocular pressure by virtue of an action confined to within the eye.

Shoulder kinesthesia after anterior glenohumeral joint dislocation

This article was presented in poster format at the Sixty-Third Annual Conference of the American Physical Therapy Association, San Antonio, TX, June 28-July 2,1987. The study was supported in part by the Montana Chapter of the American Physical Therapy Association and was submitted June 24, 1987; was with the authors for revision for 34 weeks; and was accepted June 9.1988. Reprinted from Physical Therapy with the permission of the American Physical Therapy Association. [Smith RL, Brunolli J: Shoulder kinesthesia after anterior glenohumeral joint dislocation. Phys Ther 69:106-112, 1989.]The purpose of this study was to examine kinesthesia in normal (uninjured) shoulders and in shoulders with a history of glenohumeral joint dislocations. Both shoulders of 10 healthy subjects and 8 subjects with a history of unilateral anterior dislocation were tested for accuracy of angular reproduction, threshold to sensation of movement, and end-range reproduction using a motor-driven shoulder-wheel apparatus. An analysis of variance revealed significant differences (p < 0.001) between the injured and uninjured shoulders for all three tests. Post hoc analysis showed significant differences (p < 0.02) between the involved shoulders and all uninvolved shoulders. No significant difference was found among the uninvolved shoulders. The results of this study indicate that kinesthetic deficits occur after glenohumeral dislocation and may result in abnormal neuromuscular coordination and subsequent reinjury of the shoulder. Clinicians should consider rehabilitation of shoulder kinesthesia using therapeutic activation of the shoulder joint and muscle receptors when treating patients with previous dislocations. J Orthop Sports Phys Ther 1990;11(11):507-513.

Clinical use of home and ambulatory blood pressure monitoring

Blood pressure measurements made in the physician's office with a mercury-column sphygmomanometer traditionally have been the standard for diagnosis of hypertension and determination of the efficacy of antihypertensive agents. The utility of this measurement is limited, however, by the characteristic variability of blood pressure; office blood pressure readings are not always reliable indicators of pressures occurring throughout the course of the day. Therefore, blood pressure measurements performed by patients or family members at home and automatic ambulatory blood pressure monitoring are two supplementary methods used in the clinical management of hypertension. In this article, the role of these methods in the diagnosis of hypertension and other cardiovascular disorders as well as in the evaluation of the efficacy of antihypertensive therapy is addressed.

Prognosis of patients with AIDS requiring intensive care

The Acute Physiology and Chronic Health Evaluation (APACHE) II classification, a measure of severity of illness in patients requiring intensive care, was devised before the rapid expansion of the acquired immunodeficiency syndrome (AIDS) epidemic. To determine the applicability of the APACHE II system to AIDS, we related observed in-hospital death rates to those predicted by APACHE II in 83 patients with AIDS. In a control group of patients without AIDS (n = 166) mean predicted and observed death rates (34.1 vs 31.3 percent) were similar. For the AIDS group overall observed mortality (63.9 percent) was significantly greater than that predicted by APACHE II (45.8 percent). The subgroup with Pneumocystis pneumonia requiring mechanical ventilation (n = 37) had an observed mortality (86.5 percent) that significantly exceeded the predicted value (44.3 percent), whereas all other AIDS patients (n = 46) showed similar predicted and observed death rates (47.0 vs 45.7 percent). APACHE II prediction of death rate also matched observed mortality in mechanically ventilated patients without Pneumocystis infection. The discrepancy between predicted and observed mortality in patients with Pneumocystis pneumonia requiring mechanical ventilation is most likely due to the lack of an APACHE II diagnostic category that accurately reflects the severity of this disease. A new diagnostic category that provides accurate outcome prediction in this patient group would form a basis for evaluation of new therapeutic interventions.