Coherence analysis of the electrical activity of the rabbit brain in the process of the formation of the polarization dominant

It has been demonstrated by means of the method of spectral coherence analysis in rabbits, under conditions of a chronic experiment, that when a motor dominant reaction is still absent in the early stages of the dominant, interhemispheric asymmetry appears in the Coh spectra of the electrical activity of the sensorimotor cortex and the VPL nucleus of the thalamus. On the other hand, interhemispheric asymmetry appears in the Coh spectra of the electrical activity of the sensorimotor cortex and the CA ₃ field of the dorsal hippocampus only at the stage at which the motor dominant reaction is recorded. The asymmetry in the alpha and beta ranges of the frequencies in the Coh spectra of the biopotentials of the investigated regions, which coincides with the attainment of the motor dominant reaction, is associated with the processes of the organization of movement.Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 39, No. 3, pp. 520–526, May–June, 1989.     

Ribonuclease activity of the “myofibrillary” fraction of normal and autolyzed muscle tissue

The separation in a sucrose gradient of the myofibrillary fraction of normal and autolyzed muscle tissue gave 4 components. During post-mortem destruction of the tissue there was observed a slight decrease of the myofibrillary fraction yield and also certain changes in the distribution of protein between different components. Under the selected conditions RNase activity was found in all 4 components. During the course of autolysis enzymatic activity increased in the whole myofibrillary fraction, as well as in the lysosomal-mitochondrial components of myofibrils.Research Laboratory, Ministry of Health of the USSR, Moscow. Translated from Buylleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 5, pp. 533–537, May, 1978.     

Computer analysis of the amino acid sequences in gp41 of apathogenic African green monkey (AGM) virus,less pathogenic HIV-2 and highly pathogenic SIV and HIV-1 lentiviruses

The bestfit computer program was used to compare the amino acid sequence of the gp160 envelope glycoprotein of an apathogenic AGM and the pathogenic SIV_AGM monkey lentiviruses. It was found that the gp120 envelope glycoproteins of these viruses resembled each other in their functional domains. However, an insert of 40 amino acids was found in the gp41 envelope glycoproteins of the pathogenic SIV_AGM virus in the amino acid sequence between the membrane anchoring sequence and the carboxyterminus. The insert introduced a new RRIR proteolytic cleavage signal into gp41. Comparing HIV-1 gp41 to that of the pathogenic SIV_AGM virus revealed that the HIV-1 sequence contains an RR sequence that also serves as a signal for proteolytic cleavage. Comparing HIV-2 gp41 to the apathogenic and pathogenic simian immunodeficiency viruses revealed that HIV-2 gp41 lacks the above proteolytic cleavage signal. It is hypothesized that the pathogenic human and simian immunodeficiency lentiviruses can be proteolytically cleaved at the carboxyterminus of gp41, releasing two peptides: a) an immunodeficiency 58 amino acid peptide and b) an IL-2-like peptide. The apathogenic AGM virus and the less pathogenic HIV-2 lack one proteolytic cleavage signal in the gp41 amino acid sequence and therefore can release only the IL-2-like peptide but not the immunodeficiency peptide. If indeed the pathogenic SIV_AGM and HIV-1 do release an immunodeficiency peptide, then such a peptide can be regarded as a toxin. Immunization of healthy individuals or HIV-1 patients against the toxic effect of the viral gp41 toxic peptide might prevent damage to the immune system when the virus reactivation leads to ARC and AIDS in infected individuals. Synthetic peptides modeled according to the immunodeficiency peptide (the toxin) can be used to produce anti-toxin antibodies in healthy HIV-1 infected individuals. Such anti-toxin antibodies can be used for passive immunization of AIDS patients or for active immunization of HIV-1 positive individuals prior to ARC or AIDS.     

Isolation of a hemagglutinating,immunizing, and non-infectious subunit of the rabies virion

Summary Purified rabies virus treated with saponin (1 mg/ml) at 37° C for 20 minutes showed a loss in infectivity to 0.01 per cent and a significant increase in hemagglutinating activity. After CsCl density gradient centrifugation the hemagglutinating activity of saponin-treated virus showed a density of 1.29 g/ml whereas virus-bound hemagglutinin banded at 1.20 and 1.22 g/ml. In electron micrographs saponin-treated virus showed coiled and looped filaments possibly originating from the virus surface; gradient fractions associated with hemagglutinating activity appeared as polydisperse but otherwise homogeneous network of loops and coils. Deoxycholate treatment destroyed these structures as well as the hemagglutinating activity of the preparation. Potency testing of gradient purified virus and virus subunits showed that the hemagglutinin preparation contained the total immunizing capacity of the rabies virus particle, whereas the complement fixing, non-hemagglutinating material (density 1.32 g/ml) had only little protective activity. In serum-neutralization tests antibody titers of 15000 were achieved after application of 2 g protein of each, virion- and hemagglutinin vaccine; the same amount of complement fixing antigen resulted in a titer of 112 only. The significance of these results for the production of a non-dangerous, antirabies split-virus vaccine is discussed.     

Effect of resveratrol in experimental osteoarthritis in rabbits

Objective: Resveratrol (trans-3,4,5-trihydroxystilbene) is a phytoalexin found in high concentration in the skins of grapes and red wines which has been shown to have antiinflammatory, anticancerogen and antioxidant properties. Resveratrol is a potent and specific inhibitor of nuclear factor kappa B (NF-B). Resveratrol also inhibits COX-2 gene expression and enzyme activity. We aimed to determine the in vivo effects of intra-articular injections of resveratrol on cartilage and synovium in an experimental osteoarthritis (OA) model in rabbits.Methods: As OA model, rabbits underwent unilateral anterior cruciate ligament transection (ACLT). Five weeks after test group was injected with 10 Mol/kg resveratrol in dimethylsulphoxide (DMSO) in the knees once daily for two weeks and as the control group at the same time DMSO was injected into the knees. All rabbits were killed one week after the last injection. Cartilage tissue and synovium were evaluated with a histological scoring system.Results: Histological evaluation of cartilage tissue by H&E staining revealed a significantly reduced average cartilage tissue destruction score of 1.7 in the resveratrol group versus 2.8 in the control group (p = 0.016). Loss of matrix proteoglycan content in cartilage was also much lower, as determined by safranin O staining. Scores of synovial inflammation didnt show difference between groups (1,3 vs 2,2; p = 0.057).Conclusion: A characteristic parameter in arthritis is the progressive loss of articular cartilage. This study suggests that intraarticular injections of resveratrol starting at the onset of disease may protect cartilage against the development of experimentally induced OA.Received 24 November 2004; returned for revision 29 November 2004; accepted by J. Hamilton 13 December 2004     

Vergleichende Körperwasserbestimmungen mit Hilfe von N-Acetyl-4-aminoantipyrin und Alkohol

Zusammenfassung 1. Bei 13 gesunden Versuchspersonen wurden Alkoholtrinkversuche durchgeführt; gleichzeitig (bei 10 dieser Versuchspersonen) mit Hilfe der NAAP-(N-Acetyl-4-aminoantipyrin-) Methode die Körperwasserkonzentrationen bestimmt.2. Die mit Hilfe der Alkoholmethode ermittelten GKW-(Gesamtkörperwasser-) Werte stimmten gut mit den GKW-Konzentrationen überein, die mit NAAP bestimmt wurden.3. Dabei war es gleichgültig, ob man die Blutalkoholkonzentrationen direkt (mit Hilfe des Widmark-Verfahrens — bei photometrischer Messung der Bichromatschwefelsäure —) oder indirekt aus der (mit dem Breathalyzer bestimmten) Atemalkoholkonzentration ermittelte.4. Die NAAP-Werte lagen fast in allen Fällen etwas über den Alkoholwerten, jedoch war die Differenz verhältnismäßig gering (geringer als bei früheren Versuchen zwischen Alkohol- und Antipyrin-Werten). Die Durchschnittswerte betrugen 53,8% (NAAP) und 53,0% (Alkohol; Widmark-Methode).5. Da die mit Hilfe der Widmark-Methode ermitteltenc ₀- bzw. GKW-Werte mit den aus der Atemanalyse (mittels Breathalyzer) gewonnenen Resultaten praktisch übereinstimmen, kann die Atemalkoholbestimmung mit Hilfe eines exakt arbeitenden Gerätes (Breathalyzer) zur Feststellung des Körperwassergehaltes empfohlen werden.6. Die Verwendung des Breathalyzer-Gerätes zur GKW-Bestimmung hat den Vorteil, daß die Körperwasserkonzentration mit Hilfe von Alkohol ohne Blutentnahmen (und ohne eine Injektion) ermittelt werden kann, Wiederholungs- und Vergleichsbestimmungen demzufolge ohne erhebliche Belastung für die Versuchspersonen möglich sind.     

Role of acute trauma in development of osteoarthritis

Two canine acute transarticular loading models have been developed to study the role of acute traumatic cartilage damage in the development of osteoarthritis. One model involves damage to a closed joint and has the advantage of maintaining normal joint biology. The second model involves impaction of an open joint with direct visualization of the cartilage and has the advantages of being able to change the placement, intensity, and geometry of the impaction. Comparison of preliminary histochemical data at 2 weeks and 3 months for the open joint model with previously published data on the closed joint model is consistent with the two models having similar initial features that include surface cracks and step fractures of the zone of calcified cartilage. The early changes include loss of proteoglycan, expression of the pro-inflammatory markers such as TNF- and IL-1, and the metalloprotease stromelysin. By 3 months, cloning is present. The models will be useful in evaluating two hypotheses:one, that there is a threshold of damage that must be exceeded before the lesions become progressive and two, the cracks in the zone of calcified cartilage contribute to progression of osteoarthritis by acting as sites of endochondral ossification and thereby decreasing cartilage thickness.Lecture presented at the Symposium on Models of Osteoarthritis during the Conference, Inflammation '93, Vienna, Austria, October 12, 1993.     

Prostate specific antigen and prostate specific acid phosphatase in adenocarcinoma of Skene's paraurethral glands and ducts

An autopsy case of adenocarcinoma of Skene's paraurethral gland co-incident with renal cell carcinoma is described. The adenocarcinoma showed distinct prostate specific antigen and prostate specific acid phosphatase pointing to the equivalence between the male prostate and Skene's paraurethral glands and ducts. Skene's gland are the homologue of the prostate in females and tumours arising from them are immunohistochemically similar to male prostate carcinoma.In the title and text the authors used the official term of Nomina Anatomica paraurethral (Skene's) glands and ducts. Nevertheless recently published data on cross-antigenicity between the male prostate and Skene's glands and the newly discovered exocrine and neuroendocrine parameters of the prostate homologue in the female, comparable with the male prostate (Zaviai 1987), support the use of the same term — the prostate — for prostatic tissue in both sexes (Zaviai 1987, Zaviai et al. 1985). The designations female prostate homologue or female prostate equivalent are a compromise between terms the female prostate and Skene's paraurethral glands.     

Transfer of tumor specific immunity with “immune” RNA: prospects for the treatment of human cancer

Summary Ribonucleic acids extracted from specifically sensitized lymphoid cells (I-RNA) have been shown to transfer specific immunoreactivity to normal non-immune lymphoid cells. Evidence for the transfer by I-RNA, of immune responses to tumor-associated antigens of animal and human neoplasms, in vivo and in vitro, is reviewed. Results obtained in our laboratory and in other laboratories indicate that xenogeneic, allogeneic and syngeneic I-RNA extracts mediate specific cytotoxicity to tumor cells, in vitro, and mediate transplantation resistance and tumor rejection responses in vivo. Our results suggest that I-RNA preparations fail to elicit immune responses directed against self antigens. By contrast, I-RNA's directed against non-self tumor-associated antigens appear to induce lymphocytes to effect specific anti-tumor immune responses. The mechanisms responsible for the failure of I-RNA to initiate immune responses against self antigens are not known at present and demand investigation.Preliminary results of a clinical Phase I trial of immunotherapy with xenogeneic I-RNA in selected cancer patients are reviewed. I-RNA might offer promise as a new modality for the immunotherapy of human cancer.Recipient of a postdoctoral fellowship from the Deutsche Forschungsgemeinschaft     

Cartilage destruction and osteophytes in instability-induced murine osteoarthritis: Role of TGFβ in osteophyte formation?

Osteoarthritis is characterized by focal cartilage destruction and marked formation of osteophytes. We have investigated the possible relationship between site specific occurrence of cartilage damage and osteophytes in the collagenase induced murine osteoarthritis model. The degree of instability of the joint correlated with the amount of cartilage loss. Moreover, cartilage damage in the medial tibial plateau correlated only strongly with the osteophyte at the medial plateau, whereas a similar, site directed trend was noted for lateral damage and lateral osteophytes. A separate study with intraarticular injection of TGF1 in normal murine knee joints revealed that this factor can induce osteophytes at characteristic sites, suggesting a role of endogenous TGF in this phenomenon.Lecture presented at the Symposium on Models of Osteoarthritis during the Conference, Inflammation '93, Vienna, Austria, October 12, 1993.     

Inhibition of L-type calcium channels by internal GTP [γS] in mouse pancreatic β cells

Pretreatment of pancreatic cells with pertussis toxin resulted in a 30% increase in peak whole-cell Ca²⁺ currents recorded in the absence of exogenous intracellular guanine nucleotides. Intracellular application of 90 M GTP[S], by liberation from a caged precursor, resulted in 40% reduction of the peak Ca²⁺ current irrespective of whether the current was carried by Ca²⁺ or Ba²⁺. Effects on the delayed outward K⁺ current were small and restricted to a transient Ca²⁺-dependent K⁺ current component. Inhibition by GTP[S] of the Ca²⁺ current was not mimicked by standard GTP and could not be prevented either by pretreatment with pertussis toxin or by inclusion of GDP[S] or cyclic AMP in the intracellular medium. The inhibitory effect of GTP[S] could be counteracted by a prepulse to a large depolarizing voltage. A similar effect of a depolarizing prepulse was observed in control cells with no exogenous guanine nucleotides. These observations indicate that inhibition of cell Ca²⁺ current by G protein activation results from direct interaction with the channel and does not involve second-messenger systems. Our findings also suggest that the cell Ca²⁺ current is subject to resting inhibition by G proteins.     

Mechanical properties of mammalian single smooth muscle cells I. A low cost large range microforce transducer

Summary A transducer has been developed for measuring the minute forces generated during isometric contractions (1.0–10.0N) of single smooth muscle cells from the pig urinary bladder and the human uterus. In addition to its high sensitivity, resolution and stability (100 mVN^–1, <0.1N and <2.0N h^–1), the transducer features a very wide range (100–140N) with good linearity, enabling measurement of contractions as well as passive force-length characteristics within one uninterrupted measurement session. Since the transducer features an independent and interchangeable force to displacement conversion system, different force ranges can be realized by inserting force conversion systems with different compliances.     

„Leptospira Mini“ ein neuer Serotyp pathogener Leptospiren

Zusammenfassung Auf Grund ihres immunbiologischen Verhaltens gehören die Leptospirenstämme Sari, Ghidorsi und Szwajizak zu demselben serologischen Leptospirentyp, für den der Name Leptospira Mini vorgeschlagen wird.Der Stamm Sari wurde 1942 vonMino sowieVercelli in Italien isoliert. Der Stamm Ghidorsi wurde von uns im Zuge unserer Leptospirenforschungen bei einer Reisfeldarbeiterin der Po-Ebene nachgewiesen. Der Stamm Szwajizak, der vonSmith, Brown, Tonge u. Mitarb. im Jahre 1954 beschrieben wurde, ist in Nord-Qeensland gefunden worden. Der Stamm Sari und Ghidorsi gehören dem kompletten Biotyp (AB), der Stamm Szwajizak dem inkompletten (A) an.Leptospira Mini gehört zur Serogruppe hebdomadis. Ihre Virulenz ist schwach und ihre Bedeutung als Erreger menschlicher Leptospiren-infektionen scheint gering zu sein.     

On the regulation of the expressed L-type calcium channel by cAMP-dependent phosphorylation

The Ca²⁺ channel subunits _1C-a and _1C-b were stably expressed in Chinese hamster ovary (CHO) and human embryonic kidney (HEK) 293 cells. The peak Ba²⁺ current (I _Ba) of these cells was not affected significantly by internal dialysis with 0.1 mM cAMP-dependent protein kinase inhibitor peptide (mPKI), 25 M cAMP-dependent protein kinase catalytic subunit (PKA), or a combination of 25 M PKA and 1 M okadaic acid. The activity of the _1C-b channel subunit expressed stably in HEK 293 cells was depressed by 1 M H 89 and was not increased by superfusion with 5 M forskolin plus 20 M isobutylmethylxanthine (IBMX). The _1C-a·₂·₂/ complex was transiently expressed in HEK 293 cells; it was inhibited by internal dialysis of the cells with 1 M H 89, but was not affected by internal dialysis with mPKI, PKA or microcystin. Internal dialysis of cells expressing the _1C-a·₂·₂/ channel with 10 M PKA did not induce facilitation after a 150-ms prepulse to +50 mV. The Ca²⁺ current (I _Ca) of cardiac myocytes increased threefold during internal dialysis with 5 M PKA or 25 M microcystin and during external superfusion with 0.1 M isoproterenol or 5 M forskolin plus 50 M IBMX. These results indicate that the L-type Ca²⁺ channel expressed is not modulated by cAMP-dependent phosphorylation to the same extent as in native cardiac myocytes.     

Endothelial cilia in human aortic atherosclerotic lesions

Summary Primary cilia were present in the endothelial cells of human aortic fatty dots and streaks but not in those of normal intima. They had the features of cilia of the 9+0 axonemal configuration observed in many other cells. A lateral foot process and transitional fibers anchored the ciliary basal body in the cytoplasm, but rootlets were not identified in material examined. Ladder-like configurations interconnected the two centrioles (=diplosome) of control endothelium.The primary cilia of endothelium differed from those of the rudimentary type observed in smooth muscle cells in similar lesions of man, but shared many features with cilia of those present in experimental atherosclerosis in rabbit.Cilia were rarely described in vascular endothelium. It is believed that, to date, they were not reported to occur in normal or pathological arteries in man.It is being stressed that whereas the significance of these unusual organelles remains uncertain, their widespread occurrence may indicate that their role is more important than was believed previously, and they should cease being a curiosity only.Presented-in-part at the Workshop of the American Heart Association: Evolution of the Human Atherosclerotic Plaque, Rockville, Maryland, September 20–23, 1986.Dedicated to Professor Dr. Gotthard Schettler, Department of Internal Medicine, University of Heidelberg, FRG, on the occasion of his 60 birthday (April, 1987).     

Immunolocalization of 15-kDa membrane proteins in the kidneys of normal and acidotic rats

Proteins with apparent molecular masses between 15 kDa and 17 kDa were enriched from rat renal brush-border membranes by preparative gel electrophoresis and used for immunization of rabbits. The serum of one of the rabbits reacted in Western blots of separated renal brush-border proteins with a single 15-kDa band. A comparably strong reaction is seen with a 15-kDa band of renal endosomal proteins. Basolateral membranes show a much weaker reaction. In light- and electron-microscopic studies the serum stains brush-border membranes and endosomes in rat proximal tubule cells, but not mitochondria and basolateral membranes. In cortical collecting ducts, principal cells are not stained with the antiserum. -type (H⁺-secreting) intercalated cells bind the antibodies at apical tubulovesicles. The luminal membrane is scarcely labelled. Conversely, -type (HCO ₃ ^– -secreting) intercalated cells exhibit antibody binding to their basolateral membrane. Thus, the antiserum detects 15-kDa proteins differently sorted in -and -intercalated cells. After induction of an acute (6 h) metabolic acidosis, the antibody-binding pattern changes only in intercalated cells, type , and occurs at the markedly enlarged luminal plasma membrane. The amount of -type intercalated cells with enlarged luminal membrane (secreting cell) increases at the expense of a cells with apical tubulovesicles (resting cell).Taken together, the antiserum detects 15-kDa proteins, the localization and adaptive changes to metabolic acidosis of which are similar to H⁺ -ATPases. The functional role of the 15-kDa proteins needs to be established in further studies.     

Anti-5-hydroxytryptamine antibodies: studies on their cross-reactivity in vitro and their immunohistochemical specificity

Summary Antibodies to 5-hydroxytryptamine (5-HT) were obtained from 4 rabbits after injections of 5-HT coupled to bovine serum albumin by means of paraformaldehyde (PF). Two methods were used to monitor the developement of antibodies (AB): the one based on the in vitro competitive binding properties of the antibodies with³(H)5-HT, the other, on their in situ binding properties to endogenous 5-HT, using the peroxidase-anti-peroxidase immunohistochemical technique, applied to paraffin embedded sections of cat brainstem. No pharmacological processing, detergents or proteolytic enzymes were used. The specificity of the antiserum was tested by competitive procedures with 20 analogs using the in vitro and in situ techniques. In vitro studies were performed with 5-HT free analogs and with analogs previously coupled with PF to lysine. Radioimmunological tests showed that the antibodies recognize mainly the ethylamine (CH₂-CH₂-NH₂)-cham of the free analogs and that the best specificity was obtained with the 5-HT conjugate (5-HT-lysine-PF). The results suggest that the hapten is coupled through the phenolic positions C4 or C5. The in situ immunohistochemical extinction assays also revealed a distinct specificity for 5-HT. Possible optical and ultrastructural applications are illustrated in the raphé nuclei of the cat. These results confirm the reliability of radioimmunological tests for studying the specificity of AB directed against haptens, provided that haptens and analogs tested were first chemically transformed to resemble the immunogen (herewith lysine-PF coupling) with regard to its antigenic structure.     

Peroxisome proliferator-activated receptor agonists inhibit inflammatory edema and hyperalgesia

Previous studies have produced conflicting data on the contribution of the peroxisome proliferator-activated receptors (PPARs) to the inflammatory process. This study investigated the effects of several PPAR and PPAR subtype-specific agonists on the inflammation and hyperalgesia produced by intraplantar carrageenan injection in unanesthetized male Sprague-Dawley rats. Intraperitoneal administration of PPAR agonists reduced edema in parallel to their potencies determined in vitro. Perfluorooctanoic acid (PFOA) inhibited carrageenan-induced edema in a dose-dependent manner, and also reduced thermal hypersensitivity. Furthermore, PFOA produced much more robust effects when administered 0.5–24 hrs before carrageenan, as compared to when it was administered 1.5 hrs after carrageenan. Intraperitoneal administration of similar doses of the PPAR agonist rosiglitazone, but not the less potent agonist, troglitazone, reduced edema when administered before but not after carrageenan. We conclude that systemic administration of potent PPAR and PPAR agonists exert anti-hyperalgesic and/or antiinflammatory actions in vivo, possibly by interfering with the initiation of inflammation.     

Oxidation of articular cartilage glyceraldehyde-3-phosphate dehydrogenase (G3PDH) occurs in vivo during carrageenin-induced arthritis

Articular cartilage proteoglycan biosynthesis was substantially inhibited by the competitive glycolytic inhibitor 2-deoxyglucose (65% at 100 mM), but to a much lesser degree (10%) by the oxidative phosphorylation uncoupler, 2,4-dinitrophenol. These results confirm that articular cartilage proteoglycan synthesis mostly utilises ATP which is generated by glycolysis. In addition, we have utilised the loss of the relatively specific labelling of glyceraldehyde-3-phosphate dehydrogenase (G3PDH) by [³H]-iodoacetic acid to show that rabbit articular G3PDH is oxidisedin vivo during the animal model of acute arthritis, carrageenin-induced arthritis, in the same way as we have previously shown that cartilage G3PDH is oxidised afterin vitro exposure to sublethal doses of H₂O₂. The oxidation of rabbit G3PDHin vivo (18 hr post-injection) corresponds with the maximal influx of PMNL cells into the arthritic synovial fluid [1] and with substantial inhibition of proteoglycan core protein synthesis [2,3]. We propose that H₂O₂ released from activated PMNLs and macrophages is responsible for the down-regulation of biosynthetic processes found in cartilage during acute inflammation.     

Tenoxicam concentrations in synovium and joint cartilage in humans

Tenoxicam is an NSAID of the oxicam group. Its distribution in articular tissues was investigated in 12 patients who required total arthroplasty of the hip. They were given tenoxicam 20 mg once daily for 8 to 30 days before surgery. Blood, synovium and cartilage samples were taken concurrently during surgery, about 14 hours after the last tenoxicam dose. The tissues were ground using a freeze grinder. Tenoxicam was assayed by HPLC. Tenoxicam concentrations averaged 6.21±3.81 g/ml in plasma, 7.56±4.67 g/g in synovium and 2.05±1.43 g/g in cartilage. The individual synovium/cartilage ratios ranged from 1.9 to 9.7. Finally tenoxicam exhibited more affinity for its target organ (synovial tissue) than for joint cartilage.