Synergistic effects of estrogen and androgen on the prostate: effects of estrogen on androgen- and estrogen-receptors, BrdU uptake, immunohistochemical study of AR, and responses to antiandrogens

To investigate the synergistic effects of estradiol (E2) and testosterone (T) on prostate growth, castrated Wistar rats were treated with 1 mg/day of T or with 1 mg/day of T and 0.01 mg/day of E2 for 6 weeks. The weight of the prostate in T + E2-treated rats was significantly higher than that in T-treated and normal rats, parallel with the bromodeoxy-uridine (BrdU) labeling index (LI). Nuclear androgen receptor (AR) content in the T + E2 group was significantly higher than that in the T group. But they were lower than that in normal rats. And there were no significant differences between the groups in nuclear estrogen receptor (ER) content. Immunohistochemical studies with the AR antibody revealed positive staining in the prostatic epithelium and stromal cells in the normal, T-treated, and T + E2-treated animals. However, castration led to loss of staining. Response to steroidal antiandrogens was also determined. Antiandrogen treatment abrogated the increases in nuclear AR content and BrdU LI, and prevented immunohistochemical staining. These results suggest that AR and ER, which were measured in this study, were not indicators of prostatic proliferation. We further need to investigate other factors, including other types of receptors, growth factors involved in epithelial-stromal interaction, and so on.

Replication of Chlamydia trachomatis and C. pneumoniae in the human monocytic cell line U-937

To elucidate whether Chlamydia trachomatis and C. pneumoniae infections occur to a significant extent in monocytes-macrophages, the human monocytic cell line, U-937, was infected with C. trachomatis L2 or C. pneumoniae TW-183. Chlamydial DNA and genus-specific antigens of the lipopolysaccharides (LPS) in epitopes of the chlamydial cell wall were detected from C. trachomatis L2-inoculated monocytes over a period of 150 days after inoculation and from the C. pneumoniae TW-183-inoculated cells during a period of 14 days. C. trachomatis-infected U-937 cells expressed significantly lower levels of CD4+, CD45RA+, CD11b+ and CD33+ cells, determined by flow cytometry, than control uninoculated cells on the seventh day after inoculation and they expressed a slightly increased level of CD4+ cells and lower levels of CD45RA+ and CD11b+ cells on the 14th day after inoculation. C. pneumoniae-infected U-937 cells expressed significantly lower levels of CD4+, CD45RA+, CD11b+ and CD33+ cells than controls on the seventh day after inoculation and an increased level of CD4+ and a lower level of CD45RA+ cells on the 14th day after inoculation. Unlike infection with C. trachomatis L2 strain, chronic persistent infection with C. pneumoniae appears not to occur in monocytes-macrophages.

[Membrane properties and cholecystokinin sensitivity of neurons in the gastrointestinal medial region of the nucleus tractus solitarius]

The medial region of the nucleus tractus solitarius (mNTS) has been shown to receive inputs from gastrointestinal afferents and to possess type A receptors of cholecystokinin (CCK) which mediate a satiety signal. In the present study, we examined the electrophysiological properties of neurons of the rat mNTS and their CCK responsiveness by means of in vitro intracellular recording. The mNTS neurons (n = 51) were classified into three groups, based on their different firing response patterns to injection of depolarizing current, showing repetitive firing ("repetitive" type, n = 21), delayed excitation ("delayed" type, n = 12) or a single action potential ("single" type, n = 18). Current-voltage (I-V) relations were different among the three types. "Repetitive" type neurons had anomalous rectification, while "delayed" type neurons showed delayed rectification. "Single" type neurons had linear I-V relations. Although the levels of the resting membrane potential, the sizes of the action potentials and the afterhyperpolarizations did not differ among the groups, input resistances of the "single" type neurons (103 +/- 12 M omega) were significantly smaller than those of "repetitive" (161 +/- 11 M omega) and "delayed" types (143 +/- 17 M omega) of neurons (p < 0.05). Bath application of CCK-8S (100nM) induced depolarization in 15 of 51 mNTS neurons. Fifty-two percent of "repetitive" type neurons, but only 25% of "delayed" type and 6% of "single" type neurons responded to CCK. Although "delayed" and "single" types of neurons were widely distributed in the mNTS, "repetitive" type neurons were localized mainly in the subnucleus centralis of the mNTS. These results suggest that the "repetitive" type neurons in the mNTS may play a predominant role in CCK-mediated functions.

Variation of seed α-amylase inhibitors in the common bean

Variation of seed α-amylase inhibitors was investigated in 1 154 cultivated and 726 non-cultivated (wild and weedy) accessions of the common bean, Phaseolus vulgaris L. Four α-amylase inhibitor types were recognized based on the inhibtion by seed extracts of the activities of porcine pancreatic α-amylase and larval α-amylase and larval α-amylase of the Mexican bean weevil, Zabrotes subfasciatus Boheman. Of the 1 880 accessions examined most (1 734) were able to inhibit porcine pancreatic α-amylase activity, but were inactive against the Z. subfasciatus larval α-amylase; 41 inhibited only the larval α-amylase activity, 52 inhibited the activities of the two α-amylases, and 53 did not inhibit the activity of either of the α-amylases. The four different inhibitor types were designated as αAI-1, αAI2, αAI-3, and αAI-0, respectively. These four inhibitor types were identified by the banding patterns of seed glycoproteins in the range of 14-20 kDa by using SDSpolyacrylamide gel electrophoresis. Additionally, four different banding patterns were recognized in accessions with αAI-1, and were designated as αAI-1a, 1b, 1c, and 1d. Two different patterns of the accessions lacking an α-amylase inhibitory activity were identified and designated as αAI-0a and αAI-0b. The largest diversity for seed α-amylase inhibitors was observed in non-cultivated accessions collected from Mexico where all eight inhibitor types were detected. The possible relationships between the variation of seed α-amylase inhibitors and bruchid resistance are discussed.

[Long term remission following relapsed CNS lymphoma]

A case of NHL which has been in long-term remission following vigorous treatment for CNS relapse with intrathecal administration of Ara-C and focal irradiation to the brain is presented. The patient was a 61-year-old man, who was successfully treated with CHOP followed by MACOP-B for diffuse large cell NHL in 1988. Five months later he was admitted to our hospital because of loss of visual acquity and numbness in the right upper and lower extremities. The presence of lymphoma cells in CSF, abnormal shadow in the left frontal lobe on a cranial CT scan and MRI scan, and positive Ga scintigraphy yielded a diagnosis of CNS relapse of NHL. Twenty one whole brain and additional 1.0Gy to the left frontal lobe of irradiation were performed. Eight days later the left tumor disappeared. Neurological remission was obtained and has continued until now.

[Phase II clinical trial of the radioactive strontium (89Sr) chloride agent, SMS. 2P for pain palliation in patients with prostate cancer with bone metastases]

The phase II clinical trial of a strontium (89Sr) chloride agent (SMS. 2P) was performed in 9 patients with painful bone metastases secondary to prostate cancer. After an intravenous administration, 89Sr circulated in the plasma and was rapidly cleared. Urinary excretion varied widely among the patients. No serious acute side effects were observed. A mild transient increase in pain was reported by 4 patients 2-4 days after administration, two of whom complained of mild nausea or vomiting. All symptoms improved and never became a clinical problem. There were some abnormal hematological parameters. In particular, a decrease in the platelet level seemed to be a marrow suppression due to 89Sr irradiation. It is difficult to discriminate between the effects of 89Sr and the progress of the disease using tumor markers. The pain level improved within 2 weeks after administration and the effect continued for at least 8 weeks, which improved the quality of life for these patients.

Activated CD4+ T cells preferentially take up lipid microspheres, but resting cells do not

Lipid microspheres (LM) used as drug carriers increase the effectiveness and reduce the toxicity of incorporated drugs. The present study is designed to determine whether or not activated T lymphocytes, which were the cells chosen first from the 'inflammatory cells', can take up LM in vitro. LM were labelled with a fluorescent probe, DiI (DiI-LM), to examine the kinetics. Flow cytometric analysis demonstrated that in freshly isolated peripheral blood mononuclear cells (PBMC), monocytes principally took up DiI-LM, while lymphocytes and granulocytes did not. When PBMC were stimulated with immobilized anti-CD3 MoAb and IL-2, cells expressing CD3, CD4, CD8 and CD16 incorporated DiI-LM. Purified CD4+ T cells, obtained by positive panning selection, were stimulated with this system. They were CD25, CD71, LFA-1-positive, and also showed an ability to take up DiI-LM, which resting cells did not. The findings were confirmed by flow cytometry and quantitative analysis of DiI. Confocal micrographs showed fluorescent granules from the probe in the cytoplasm of stimulated CD4+ T cells after incubation with DiI-LM. These results suggest that immunomodulatory agents incorporated into LM might selectively regulate the function of CD4+ or CD8+ T cells when these are activated.

[A case report of pericardial diverticulum in the upper mediastinum: surgical treatment of two cases]

Pericardial cyst and diverticulum are commonly found in areas of cardiophrenic angles. In this article, we reported on two operated cases (54-year-old female, 43-year-old male) with pericardial diverticula in upper mediastinum. On their chest CT films, well circumscribed cystic lesions were seen in the right (case 1) and left (case 2) upper mediastinum. Based on findings of imaging modalities such as CT, MRI and transesophageal ultrasonography, the lesions were suspected of benign cystic tumors such as bronchogenic cyst, lymphatic cyst, esophageal cyst and pericardial cyst. However, definite diagnoses were made by thoracotomy. Even though the cystic lesion is recognized in the upper mediastinum, pericardial diverticulum should be considered as its diagnosis as well as bronchogenic cyst, lymphatic cyst, esophageal cyst.

Eosinophils infiltration in the rat seminal vesicle associated with estradiol-17-beta-related stromal proliferation

We performed a histological quantitative analysis of collagen and smooth muscle in seminal vesicle (SV) stroma after Estradiol-17 beta (E2) administration to the immature castrated rat. On day 14 after E2 administration, collagen and smooth muscle had increased approximately five and fifteen times, respectively, over the baseline of day 0. On day 28 (14 days after the cessation of E2 administration), smooth muscle decreased to the same level as that on day 7, but collagen did not decrease during the 14 days after the cessation of E2 administration. As the proliferation of stroma, the infiltration of eosinophils was seen in the perigrandular stroma that consisted of rich collagen. The number of infiltrated eosinophils increased exponentially in the period in which collagen proliferated. But in the peripheral stroma which consists of rich smooth muscle, no eosinophil infiltration was seen. These results suggest that eosinophil infiltration into SV is related to E2 administration and to stromal proliferation, especially to collagen proliferation in this condition.

Voluntary running in male S5B/P1Ras rats fed high fat or high carbohydrate diets

Nineteen week-old male S5B/P1Ras (S5B) rats were randomly assigned to one of 4 groups as follows: (a) activity wheel access (running)/high fat diet (RF); (b) no activity wheel access (non-running)/high fat diet (NRF); (c) activity wheel access (running)/high carbohydrate diet (RC); and (d) no activity wheel access (non-running)/high carbohydrate diet (NRC) for the seven weeks duration of the experiment. Throughout the 7 wk of the experiment, rats ran more during subsequent weeks than they did the previous week. RC rats ran more than RF rats as measured by the running slopes. All groups of rats lost weight at the initiation of the experiment but significantly more weight was lost by running rats than their nonrunning counterparts. The inguinal, epididymal and perirenal/retroperitoneal (P/R) fat depots weighed significantly less in the running than in the nonrunning groups. From among the 3 fat depots, the difference was greatest in the P/R depot. There were no diet or voluntary activity effects on plasma corticosterone concentrations except at week 2 when running rats had higher concentrations than nonrunning rats.

[Chromosome findings in multiple myeloma]

Cytogenetic studies were performed on 25 patients with multiple myeloma. Five of 25 patients (20%) had chromosomally abnormal clones. The most common anomalous chromosomes were #1, #10, #12, #3, and #14. Chromosomal abnormalities of t (1 ; 10) (q42 ; q26) and t (1 ; 19) (q11 ; p13.3) were observed consistently in a Ig D myeloma patient. Patients with abnormal karyotypes were considered to be in a clinically aggressive phase because of high percentage of immature plasma cell in bone marrow and to have a poor prognosis. Current status of the chromosome findings in multiple myeloma are reviewed in this article.

T cell receptor-mediated signaling events in CD4+CD8+ thymocytes undergoing thymic selection: requirement of calcineurin activation for thymic positive selection but not negative selection

The goal of this study was to identify the differences of intracellular signals between the processes of thymic positive and negative selection. The activation of calcineurin, a calcium- and calmodulin-dependent phosphatase, is known to be an essential event in T cell activation via the T cell receptor (TCR). The effect of FK506, an inhibitor of calcineurin activation, on positive and negative selection in CD4+CD8+ double positive (DP) thymocytes was examined in normal mice and in a TCR transgenic mouse model. In vivo FK506 treatment blocked the generation of mature TCRhighCD4+CD8- and TCRhighCD4-CD8+ thymocytes, and the induction of CD69 expression on DP thymocytes. In addition, the shutdown of recombination activating gene 1 (RAG-1) transcription and the downregulation of CD4 and CD8 expression were inhibited by FK506 treatment suggesting that the activation of calcineurin is required for the first step (or the very early intracellular signaling events) of TCR-mediated positive selection of DP thymocytes. In contrast, FK506-sensitive calcineurin activation did not appear to be required for negative selection based on the observations that negative selection of TCR alpha beta T cells in the H-2b male thymus (a negative selecting environment) was not inhibited by in vivo treatment with FK506 and that there was no rescue of the endogenous superantigen-mediated clonal deletion of V beta 6 and V beta 11 thymocytes in FK506-treated CBA/J mice. DNA fragmentation induced by TCR activation of DP thymocytes in vitro was not affected by FK506. In addition, different effects of FK506 from Cyclosporin A on the T cell development in the thymus were demonstrated. The results of this study suggest that different signaling pathways work in positive and negative selection and that there is a differential dependence on calcineurin activation in the selection processes.

Effects of 15-deoxyspergualin on experimental autoimmune giant cell myocarditis of the rat

BACKGROUND

The benefits of immunosuppressive therapy for human myocarditis are controversial. The effects of a new immunosuppressant agent, 15-deoxyspergualin (DSG), on rats with experimental autoimmune myocarditis (EAM), an animal model of human giant cell myocarditis, were examined.

METHODS AND RESULTS

Lewis rats were immunized with cardiac myosin in Freund's complete adjuvant on day 0. In the first experiment, the effective doses of DSG required to prevent EAM were investigated. Rats were placed into one of five groups: the control group (A) was administered saline from days 1 to 10; group B, 0.3 mg/kg per day of DSG; group C, 1.0 mg/kg per day of DSG; group D, 3.0 mg/kg per day of DSG, and group E, 10.0 mg/kg per day of DSG. Rats were killed on day 28. The heart weight/body weight ratios of the rats of groups D and E were significantly lower than that of the control group. Macroscopic and microscopic scores for myocarditis decreased in groups D and E. In the next experiment, the effects of delayed administration of DSG in preventing autoimmune myocarditis were studied. Two groups of rats received 3.0 and 10.0 mg/kg per day of DSG from days 6 to 15, respectively. Two other groups of rats received the same doses of DSG from days 11 to 20. No preventive effect of delayed DSG treatment was observed. The effects of long-term, delayed initiation therapy then were evaluated. Rats were administered 10.0 mg/kg per day of DSG from days 6 to 25. The heart weight/body weight ratio and macroscopic and microscopic scores of the rats so treated significantly decreased compared with the controls.

CONCLUSIONS

It was demonstrated that DSG can prevent the development of cardiac myosin-induced autoimmune myocarditis.

Monovalent cation selective channel in the apical membrane of rat inner medullary collecting duct cells in primary culture

Ion channels in the apical membrane of rat inner medullary collecting duct (IMCD) were investigated by the patch clamp technique. Owing to the histological heterogeneity of IMCD, cells were cultured from the lower half of the inner medulla of Wistar rat kidney. Channel activity was rarely seen in cell attached patch, but membrane excision activated multiple units of 28.2 +/- 0.7 pS cation selective channel. A Na or K selective channel was not found. The 28 pS channel showed membrane voltage dependency, no rectification, almost equal permeability to monovalent cations (Na/K/Li/Cs/Rb/NH4 = 1:1.00:0.82:0.97:1.10:1.71) and no significant permeation to anions or divalent cations. Calcium of the cytoplasmic side from 10(-7) M to 10(-4) M affected the mean number of open channels (nPo) dose-dependently in excised patch (IC50 = 5 x 10(-6) M). 1 mM of ATP, ADP, AMP and gadolinium reversibly suppressed nPo to near zero whereas amiloride, cAMP or cGMP had no effect. Multiple conductance substates were frequently observed. These results suggested that this channel belongs to the nonselective cation channels which has been identified in other epithelia and is not responsible for amiloride sensitive Na transport through IMCD cells.

Intraoperative irradiation after palliative surgery for locally recurrent rectal cancer

BACKGROUND

In patients with locally recurrent rectal cancer, long-term disease control and survival is uncommon with single-modality therapy. This report evaluates results achieved at the Mayo Clinic (Rochester, MN) with single- or combined-modality treatment, including intraoperative irradiation.

METHODS

From 1981 to 1988, 106 patients underwent palliative surgical resections at the Mayo Clinic for locally recurrent rectal cancer. None had evidence of extrapelvic disease, and 42 received intraoperative electron beam irradiation (IORT) as a component of treatment. Gross residual disease remained after maximal surgical resection in 34 of the 42 patients and 61 of the patients who did not receive IORT. The IORT dose was 15-20 Gy in 39 patients and 10, 25, and 30 Gy in the other 3. External beam irradiation (EBRT) was administered to 41 of the 42 patients (doses > or = 45 Gy to 38 patients).

RESULTS

Kaplan-Meier survival estimates at 3 and 5 years were analyzed for the 106 patients. Palliative surgical resection alone (12 patients) resulted in a 3-year survival of 8% and a 5-year survival of 0%. Statistically significant factors relative to survival based on the univariate analysis of all patients included amount of residual tumor (microscopic vs. gross, P = 0.032) treatment method (P = 0.005), IORT versus no IORT (P = 0.0006), type of symptoms (P = 0.0075), type of fixation (P < 0.0001), and preoperative Eastern Cooperative Oncology Group status (P = 0.03). For patients who received IORT, 3-year survival with gross residual tumor or presentation with pain was 44% and 43%, respectively. Factors not associated with survival (univariate) included extended versus conventional surgical resection, grade, age, and sex. The 3-year cumulative probability of distant metastasis was 60% in the patients who received IORT and 54% in those who did not. The 3-year local relapse rates were 40% versus 93% in patients who received IORT versus those who did not.

CONCLUSIONS

Although the addition of IORT to external irradiation and maximal surgical resection appears to improve local tumor control and survival in patients who undergo palliative surgical resection for locally recurrent rectal cancer, further gains in treatment are necessary. Considering the high rates of distant metastasis, more routine systemic therapy with 5-fluorouracil (5-FU) leucovorin, 5-FU levamisole, or all three needs to be incorporated into aggressive treatment approaches. In patients with gross residual tumor after maximum surgical resection, local tumor control is inadequate despite treatment combinations including IORT. The evaluation of radiation sensitizers or biologic modifiers during external irradiation and IORT is indicated.

Proliferative capacity of oligodendrocytes in the demyelinating twitcher spinal cord

The proliferative capacity of oligodendrocytes was investigated in the spinal white matter of the twitcher mouse, a murine model of a genetic demyelinating disease globoid cell leukodystrophy (GLD), in which degeneration of oligodendrocytes due to metabolic perturbation has been well documented. In normal mice at 30 and 45 days of age, proliferating cells labeled with 5-bromo-2'-deoxyuridine (BrdU) were scarce, and the majority of BrdU-labeled cells did not immunostain with antibodies for oligodendrocytes, astrocytes, or microglia/macrophages. Only a few cells with markers for oligodendrocytes, carbonic anhydrase (CA), or the Pi form of glutathione-S-transferase (Pi), were labeled with BrdU. In the twitcher spinal cord, total numbers of BrdU-labeled cells were almost 6 times that of the normal littermate mice at 30 days of age, and 28 times at 45 days of age. However, this increase was largely due to an increase of cells labeled with F4/80, a marker for the microglia/macrophages. CA or Pi positive cells only constituted less than 10% of all labeled cells. With progression of demyelination from 30-45 days, total numbers of CA positive or Pi positive oligodendrocytes decreased, but percentages of cells double-labeled with BrdU and CA or Pi remained fairly constant. The results indicated that oligodendrocytes proliferated, to some extent, in the twitcher despite the genetic metabolic defect, and their decrease in number with progression of disease was not due to declined proliferation but rather cellular degeneration as the result of an intrinsic metabolic perturbation.

Hepatitis B virus strains with mutations in the core promoter in patients with fulminant hepatitis

OBJECTIVE

Fulminant hepatitis B can be induced by hepatitis B virus (HBV) strains with mutations in the precore region that cannot encode hepatitis B e antigen (HBeAg). Such mutations are rarely seen in HBV DNA clones from patients with fulminant hepatitis B in the United States and France. Thus, the other mutations in HBV strains causing fulminant hepatitis B need to be identified.

DESIGN

Retrospective clinical, serologic, and molecular biological studies of patients with fulminant hepatitis B.

SETTING

University and city hospitals in Japan.

PATIENTS

43 patients with fulminant hepatitis B.

MEASUREMENTS

The precore region coding for a part of the HBeAg precursor and the core promoter regulating the transcription of precore messenger RNA were sequenced in HBV DNA clones.

RESULTS

A point mutation from G to A at nucleotide 1896 in the precore region was detected in 519 (98%) of 529 HBV DNA clones from 38 patients. Two point mutations in the core promoter, from A to T at nucleotide 1762 and from G to A at nucleotide 1764, were detected in all 130 clones from the remaining 5 patients, who did not have mutations in the precore region, and in 20 (63%) of 32 clones from a patient with chronic hepatitis B who had transmitted HBV to 1 of these other 5 patients. Mutations in the core promoter were also detected in clones from 26 (68%) of the 38 patients with the precore mutation at nucleotide 1896. Neither HBeAg nor antibody to HBeAg was detected in 37 (90%) of the 41 patients tested.

CONCLUSIONS

In Japan, fulminant hepatitis B is closely associated with HBV strains that do not produce HBeAg because of mutations in the precore region, which affect translation of HBeAg, or because of mutations in the core promoter, which affect transcription of the HBeAg coding region.

Molecular cloning and functional characterization of rat plasma protein S

Plasma protein S is a cofactor of activated protein C (APC) in the regulation of the blood coagulation system. Rat protein S homogeneously purified from plasma showed cofactor activity for rat APC, but not for human APC when the APC cofactor activity was assayed using protein S- and C4b-binding protein (C4BP)-depleted human plasma. Rat plasma protein S was separated by gel chromatography into two forms, a free form and a form complexed with C4BP. Rat protein S forms complexes with rat and human C4BP in a solid-phase model with apparent dissociation constants (Kds) of 6.7 x 10(-8) and 1.2 x 10(-8) M, respectively, in the presence of 5 mM Ca2+. Human protein S also forms a complex with solid-phase human and rat C4BP with Kds of 6.3 x 10(-9) and 2.7 x 10(-8) M, respectively. Human C4BP strongly inhibited the APC cofactor activity of both human and rat protein S, whereas rat C4BP was only weakly inhibitory. The degree of the inhibitory activity of C4BP appears to depend on the affinity between protein S and C4BP. In order to evaluate the structure-function relationship of the rat protein S, the complete cDNA sequence of rat protein S was determined. This cDNA of 3,315 bp was composed of a 103-bp 5'-noncoding region, a 2,028-bp coding region that encodes a preprosequence of 41 amino acids, a mature protein S of 634 amino acids and a stop codon, and a 1,184-bp 3'-noncoding region. The rat mature protein S consisted of domains with distinct functions similar to those of human protein S, and with two potential Asn-linked glycosylation sites. The amino acid sequence of the mature form of rat protein S showed 80.4, 78.7, and 79.7% identity with those of human, bovine, and rabbit mature protein S, respectively. These findings suggest that despite the species-specificity of the APC cofactor activity of rat protein S, it is structurally very similar to human protein S. Expression of rat protein S mRNA (approximately 3.5 kb) was demonstrated by RNA blot analysis not only in the liver, but also in the lung, spleen, testis, and uterus of rats.

Isolation of an antioxidant from Penicillium roquefortii IFO 5956

In the search for antioxidants from microbial organisms, we found that Penicillium roquefortii IFO 5956 produced an antioxidant. This antioxidant was isolated from a culture broth of the strain, and its structure was identified to be 2,3-dihydroxy benzoic acid (1). The antioxidative activity of 1 was nearly equal to that of tert-butyl-4-hydroxyanisol (BHA).

Proteoglycan degradation in hemarthrosis. Intraarticular, autologous blood injection in rat knees

We determined the degradation of articular cartilage proteoglycans in a single episode of experimental hemarthrosis in rat knees. The right knee joints of rats were injected once with autologous whole blood. Both knee joints were examined histologically. Biochemical studies of cartilage proteoglycans extracted from the knees were also conducted. Histological examination revealed an accumulation of mononuclear cells in intraarticular fibrin clots and subsynovial layers 8 hours after the injection of blood. Accordingly, initiation of proteoglycan degradation occurred 8 hours after injection of blood, lasting from 1 day of limited degradation to 3 days; recovery then occurred within 7 days. The proteoglycan degradation could be inhibited by 1 mM phenylmethylsulfonyl fluoride, a general serine proteinase inhibitor, 0.1 M 6-aminohexanoic acid, a specific inhibitor of plasminogen activators, 10 mM EDTA, and 10(-6) to 10(-8) M dexamethasone, indicating that the accumulation of mononuclear cells in intraarticular fibrin clots and subsynovial layers may play an important role in cartilage damage.

Hemiresection-interposition arthroplasty for osteoarthritis of the distal radioulnar joint

Hemiresection-interposition arthroplasty of the distal radioulnar joint has been carried out in 12 men. The indication was osteoarthritis with an intact triangular fibrocartilage, or when the fibrocartilage could be reconstructed. The average age was 41 years and average follow up for 53 months. In all the patients, there was relief of pain and a significant increase in movement and in grip strength.