Spontaneous osteonecrosis of the knee: histopathological differences between early and progressive cases

We prospectively examined the physical and imaging findings, including MRI, of 23 patients with spontaneous osteonecrosis of the knee after obtaining informed consent to acquire tissue specimens at surgery. There were four men and 19 women, with a mean age of 67.5 years (58 to 77). Plain radiographs were designated as stages 1, 2, 3 or 4 according to the classification of Koshino. Five knees were classified as stage 1, five as stage 2, seven as stage 3 and six as stage 4. The histological specimens were stained with haematoxylin and eosin and tetrachrome. In the early stages of the condition, a subchondral fracture was noted in the absence of any features of osteonecrosis, whereas in advanced stages, osteonecrotic lesions were confined to the area distal to the site of the fracture which showed impaired healing. In such cases, formation of cartilage and fibrous tissue, occurred indicating delayed or nonunion. These findings strongly suggest that the histopathology at each stage of spontaneous osteonecrosis is characterised by different types of repair reaction for subchondral fractures.

Functional serotonin and histamine receptor subtypes in porcine ciliary artery in comparison with middle cerebral artery

Functional serotonin (5-HT) and histamine receptor subtypes were investigated in porcine middle cerebral and ciliary arteries. An H(1) antagonist, mepyramine, antagonized histamine-induced responses with pK(B) values of 8.91-9.10. In the presence of 1 muM mepyramine, however, histamine caused dilation through H(2) receptors in the middle cerebral but not in the ciliary artery. A 5-HT(2A) antagonist, ketanserin, antagonized 5-HT-induced responses, causing rightward shifts in the concentration-response curves with pK(B) values of 8.52-8.71. A 5-HT(1B) antagonist, SB224289, produced rightward shifts of the concentration-response curves to sumatriptan with pK(B) values (6.66) only in the middle cerebral artery. In contrast, a 5-HT(1D) antagonist, BRL15572, had no effect in either artery. An RT-PCR study demonstrated the gene expression of the mRNAs of all three receptors (5HT(1B), 5HT(1D) and 5HT(2A)) in both arteries. These results suggest that histamine-induced contraction is mediated only through functional H(1) receptor in these arteries. Interestingly, there are functional 5-HT(2A) and 5-HT(1B) receptor subtypes in the middle cerebral artery, whereas the only functional receptor is 5-HT(2A) in the ciliary artery. The difference may be important for treatment with 5-HT(1B/1D) agonists (e.g. for migraine) without ocular side effect.

Antibacterial activity of bovine lactoferrin hydrolysate against mastitis pathogens and its effect on superoxide production of bovine neutrophils

Antibacterial activity of bovine lactoferrin hydrolysates (LFH) on microorganisms isolated from bovine mastitis, and superoxide (O(2)(-)) production of bovine neutrophils were evaluated. Antibacterial effects of LFH were measured in vitro against Staphylococcus aureus, coagulase-negative staphylococci, Streptococci, Enterococci, Escherichia coli, Klebsiella pneumoniae, yeast-like fungi and Prototheca zopfii isolated from clinical cases of bovine mastitis. To compare susceptibilities against LFH, minimal inhibitory concentration (MIC) values were determined by a micro-plate assay method. Most organisms were sensitive to LFH. Prototheca zopfii was highly sensitive to LFH; the growth of the microorganism was inhibited completely even at 1 mug/ml. Staphylococcus aureus and Escherichia coli were resistant to LFH. The production of O(2)(-) by bovine neutrophils was used to evaluate the effect of LFH administration on functional activity. Increase in O(2)(-) production by bovine neutrophils occurred upon addition of LFH to neutrophils. These results demonstrate that LFH possesses antibacterial activity against pathogens that cause mastitis and activates neutrophil superoxide production.

Histologic changes after meniscal repair using radiofrequency energy in rabbits

PURPOSE

Our purpose was to investigate histologic changes in the rabbit meniscus after meniscal repair via radiofrequency energy (RFE).

METHODS

Twenty Japanese white rabbits underwent bilateral knee arthrotomies, and a longitudinal tear was made in the avascular area of both medial menisci. On the right knees, RFE treatment (60 degrees C and 40 W) was performed on the femoral surface of the meniscal tear in monopolar mode. On the left knees, the meniscus was left untreated as a control. The rabbits were killed at 0, 1, 2, 4, or 12 weeks after surgery, and all medial menisci were examined histologically. The expression of autocrine motility factor in meniscal fibrochondrocytes was examined by immunohistochemical analysis.

RESULTS

Histologic examination at baseline showed fusion of collagen fibers in the tear. Failure of fusion was found in 2 of 4 menisci at 2 weeks and 1 of 4 menisci at 4 and 12 weeks. One week after surgery, the specimens showed an acellular area as a result of fibrochondrocyte death. The acellular area expanded deeper until 4 weeks and was reduced at 12 weeks. On the femoral surface of the RFE-treated area, fibroblast proliferation was found at 2 weeks, and fibroblasts had invaded into the meniscus tissue from the meniscal surface at 12 weeks. Immunohistochemical analysis showed that the expression of autocrine motility factor in RFE-treated menisci was significantly higher than that in control menisci from 1 to 12 weeks.

CONCLUSIONS

RFE treatment at 60 degrees C and 40 W fused the collagen fiber in the meniscal tear in rabbits just after surgery. After RFE treatment, an acellular area developed as a result of fibrochondrocyte damage. RFE caused fibroblast proliferation at 2 weeks. The acellular area was reduced by cell repopulation at 12 weeks.

CLINICAL RELEVANCE

RFE may induce fibroblast proliferation for meniscal repair.

Complement Receptor Type 3 (CR3)- and Fc Receptor (FcR)-Mediated Matrix Metalloproteinase 9 (MMP-9) Secretion and Their Intracellular Signalling of Bovine Neutrophils

Complement receptor type 3 (CR3)- and Fc receptor (FcR)-mediated metalloproteinase-9 (MMP-9) secretion and their intracellular signalling of bovine neutrophils were evaluated. Relative density of MMP-9 secreted by neutrophils stimulated with opsonized zymosan (OPZ, stimulant for CR3) was significantly (p < 0.05) increased when the OPZ concentration was increased from 0 to 0.4 mg/ml. Similar results were obtained for neutrophils stimulated with heat-aggregated IgG (Agg-IgG, stimulant for Fc receptor) at concentrations from 0 to 0.40 mg/ml. Preincubation of neutrophils with 1-30 nmol/L wortmannin (phosphoinositide 3-kinase inhibitor) resulted in inhibition of MMP-9 secretion induced by stimulation with OPZ and Agg-IgG in a concentration-dependent manner, 30 nmol/L wortmannin causing complete inhibition. Similarly, preincubation of neutrophils with 0-100 mumol/L genistein (tyrosine kinase inhibitor) also resulted in inhibition of OPZ- and Agg-IgG-induced MMP-9 secretion in a concentration-dependent manner, with 100 micromol/L genistein causing complete inhibition. Significant (p < 0.05) positive correlations were found between MMP-9 and luminal-dependent chemiluminescent response (LDCL) in the case of stimulation with OPZ (r = 0.754) and in the case of stimulation with Agg-IgG (r = 0.728). Our findings suggested that CR3 and FcR play a critical role in production of MMP-9 and may be regulated by intracellular signal transduction, including that by phosphoinositide 3-kinase (PI3K) and tyrosine kinase (TK).

Potentiation by neuropeptide Y of histamine H1 receptor-mediated contraction in rat blood vessels

Histamine-induced contraction and its potentiation by neuropeptide Y were investigated in rat blood vessels. Rat arteries and veins constricted with single concentrations of histamine dose-dependently (0.1-100 microM). This histamine-induced contraction immediately desensitized. Histamine H1 receptor antagonists, 1 microM mepyramine and 1 microM diphenhydramine, abolished this transient contraction completely, whereas cimetidine, phentolamine, reserpine and tetrodotoxin failed to inhibit the contraction. Histamine H1 receptor mRNA level by reverse transcription-polymerase chain reaction was quite parallel to histamine H1 receptor-mediated contraction, indicating that the contraction is mediated through histamine H1 receptors in the smooth muscle. Neuropeptide Y (10 nM in arteries and 3 nM in veins, respectively) significantly potentiated histamine H1 receptor-mediated contraction via neuropeptide Y1 receptors in most of rat blood vessels. Since the phospholipase C inhibitors, neomycin (1 mM) and 2-nitro-4-carboxyphenyl-N, N-diphenylcarbamate (NCDC, 10 microM), respectively, specifically abolished the potentiation, the potentiation by neuropeptide Y may depend on activation of phospholipase C.

A comparison of arthroscopic single- and double-bundle posterior cruciate ligament reconstruction: review of 20 cases

In the study reported here, we evaluated postoperative outcomes of arthroscopic posterior cruciate ligament (PCL) reconstruction using hamstring tendons and compared single- and double-bundle reconstructions. Twenty patients with isolated PCL tears and multiligamentous knee injuries were enrolled. Single-bundle (group S) and double-bundle (group D) reconstructions were applied to 10 patients each. Posterior tibial translation was measured using stress radiography before surgery and 2 years after surgery. Second-look arthroscopy was also performed in each knee. Two years after surgery, mean side-to-side differences in posterior tibial translation of groups S and D were 3.4 mm (SD, 3.0 mm) and 4.9 mm (SD, 2.8 mm), respectively. There was no significant difference in short-term stability between the 2 groups. Second-look arthroscopy showed 3 ruptures of the posteromedial bundle in the double-bundle technique.

Dramatic remission of treatment-resistant depression after the cessation of tricyclic antidepressants

Recently, tricyclic antidepressants (TCAs) have been used mainly for treatment-resistant depression (TRD) because of their significant side effects . We report a patient whose prolonged depressive symptoms dramatically improved after the cessation of TCAs. TCAs may cause deterioration of depressive symptoms due to their neurotoxicity.

Potentiation by neuropeptide Y of 5HT2A receptor-mediated contraction in porcine coronary artery

Potentiation by neuropeptide Y of serotonin (5-HT)-induced vasoconstriction was investigated in porcine coronary artery. 5-HT caused concentration-dependent contraction through 5-HT2A receptors. Neuropeptide Y (30 nM) significantly increased the 5HT-induced contraction by 16+/-5% in arteries with intact endothelium. Removal of the endothelium abolished the potentiation. A neuropeptide Y1 antagonist, BIBP3226, blocked this neuropeptide Y-induced potentiation. In vessels with intact endothelium, the potentiation by neuropeptide Y was inhibited by in the presence of a cyclo-oxygenase inhibitor, indomethacin (30 microM), but not by the presence of ETA or ETB endothelin receptor antagonists or an NO synthase inhibitor, NG-nitro-L-arginine (L-NNA) (1 mM) at all. A thromboxane A2 (TXA2) synthase inhibitor, ozagrel, and prostanoid TP receptor antagonists, seratrodast and ONO-3708, also inhibited the neuropeptide Y-induced potentiation. In the endothelium-denuded arteries, a prostanoid TP receptor agonist, U-46619 (0.01-0.1 nM), potentiated 5-HT-induced contraction. These results indicate that neuropeptide Y potentiates the 5-HT-induced contraction, due to release of TXA2 from the endothelium via neuropeptide Y1 receptors, in porcine coronary artery.

Changes in biochemical parameters after anterior cruciate ligament injury

We studied the biochemical characteristics of human knees with deficient anterior cruciate ligaments (ACL) and analysed their relationship to the time after ligamentous injury. Thirty-two patients with isolated ACL-injured knees and six healthy volunteers were enrolled. Synovial fluid samples were centrifuged after aspiration during arthroscopic examination, and aliquots of supernatant were frozen and stored at -80 degrees C. The samples were analysed for interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, IL-6, matrix metalloproteinase (MMP)-3, and tissue inhibitor of metalloproteinase (TIMP)-1 using commercially available sandwich enzyme-linked immunosorbent assay. In fluid from ACL-injured knees, the average concentrations of IL-6, MMP-3 and TIMP-1 were highly elevated in comparison with normal controls. There was a statistically significant correlation between the concentrations of MMP-3 and IL-6. The IL-6 and TIMP-1 concentrations were interrelated. The concentration of MMP-3 remained high, independent of the duration since the injury, whereas the TIMP-1 and IL-6 levels decreased. The results suggest that the timing of the treatment of an ACL-injured knee might be of importance.

Effect of aging on blood pressure in Leh, Ladakh, a high-altitude (3524 m) community, by comparison with a Japanese town

The effect of aging on blood pressure (BP) and heart rate (HR) was investigated in a cross-sectional study in the high-altitude community of Leh, Ladakh (altitude: 3524 m) and a Japanese community in U town, Hokkaido (altitude: 25 m). BP and HR were obtained in a sitting position from 332 subjects 13-81 years of age in Ladakh, and from 216 Japanese citizens, 24-79 years of age. Measurements were taken after a 2-min rest, using a semi-automated BP device (UA-767 PC, A and D Co. LTD, Tokyo). High-altitude people showed higher diastolic BP and HR values than lowland people (83.2 vs. 76.9 mmHg and 78.6 vs. 69.2 bpm, P < 0.001), but no difference in systolic BP. Highland people also showed a steeper BP increase with age than the lowland people (systolic BP: 0.7476 vs. 0.3179 mmHg/year, P < 0.0005; diastolic BP: 0.3196 vs. 0.0750 mmHg/year, P < 0.001). This chronoecologic investigation in Ladakh examined the circulation as a physiological system at high-altitude. Our data indicate the need for a more comprehensive cardiovascular assessment for a better diagnosis and a more fruitful treatment. Longitudinal observations of effects of socio-ecologic factors on the cardiovascular system should help prevent strokes and other cardiovascular events, especially at high altitude.

Motility and growth of human bone-marrow mesenchymal stem cells during ex vivo expansion in autologous serum

Human bone-marrow mesenchymal stem cells have an important role in the repair of musculoskeletal tissues by migrating from the bone marrow into the injured site and undergoing differentiation. We investigated the use of autologous human serum as a substitute for fetal bovine serum in the ex vivo expansion medium to avoid the transmission of dangerous transfectants during clinical reconstruction procedures.

Autologous human serum was as effective in stimulating growth of bone-marrow stem cells as fetal bovine serum. Furthermore, medium supplemented with autologous human serum was more effective in promoting motility than medium with fetal bovine serum in all cases. Addition of B-fibroblast growth factor to medium with human serum stimulated growth, but not motility. Our results suggest that autologous human serum may provide sufficient ex vivo expansion of human bone-marrow mesenchymal stem cells possessing multidifferentiation potential and may be better than fetal bovine serum in preserving high motility.

Chronoecological health watch of arterial stiffness and neuro-cardio-pulmonary function in elderly community at high altitude (3524 m), compared with Japanese town

Effects of high altitude on arterial stiffness and neuro-cardio-pulmonary function were studied. Blood pressure (BP) and heart rate (HR) were measured in a sitting position on resting Ladakhis, living at an altitude of 3250-4647 m (Phey village, 3250 m: 17 men and 55 women; Chumathang village, 4193 m: 29 men and 47 women; Sumdo village, 4540 m: 38 men and 57 women; and Korzok village, 4647 m: 84 men and 70 women). The neuro-cardio-pulmonary function, including the Kohs block design test, the Up and Go, the Functional Reach and the Button tests, was examined in 40 elderly subjects (19 men and 21 women, mean age: 74.7 +/- 3.3 years) in Leh, Ladakh (altitude: 3524 m), for comparison with 324 elderly citizens (97 men and 227 women, mean age: 80.7 +/- 4.7 years) of Tosa, Japan (altitude: 250 m). Cardio-Ankle Vascular Index (CAVI) was measured as the heart-ankle pulse wave velocity (PWV) in these subjects using a VaSera CAVI instrument (Fukuda Denshi, Tokyo). SpO(2) decreased while Hb and diastolic BP increased with increasing altitude. At higher altitude, residents were younger and leaner. Women in Leh vs. Tosa had a poorer cognitive function, estimated by the Kohs block design test (3.7 +/- 3.6 vs. 16.4 +/- 9.6 points, P < 0.0001) and poorer ADL functions (Functional Reach: 13.7 +/- 7.0 cm vs. 25.3 +/- 8.7 cm, P < 0.0001; Button test: 22.5 +/- 4.8 vs. 14.8 +/- 5.7 s, P < 0.0001). Time estimation was shorter at high altitude (60-s estimation with counting: 41.1% shorter in men and 23.0% shorter in women). A higher voltage of the QRS complex was observed in the ECG of Leh residents, but two times measurement of CAVI showed no statistically significant differences between Leh and Tosa (two times of CAVI measures; 9.49 vs. 10.01 m/s and 9.41 vs. 10.05 m/s, respectively), suggesting that most residents succeed to adapt sufficiently to the high-altitude environment. However, correlation of CAVI with age shows several cases who show an extreme increase in CAVI. Thus, for the prevention of stroke and other adverse cardiovascular outcomes, including dementia, CAVI may be very useful, especially at high altitude. In conclusion, elderly people living at high altitude have a higher risk of cardiovascular disease than low-latitude peers. To determine how these indices are associated with maintained cognitive function deserves further study by the longitudinal follow-up of these communities in terms of longevity and aging in relation to their neuro-cardio-pulmonary function.

Halothane enhances dopamine metabolism at presynaptic sites in a calcium-independent manner in rat striatum

BACKGROUND

We have previously reported that halothane anaesthesia increases the extracellular concentration of dopamine (DA) metabolites in the rat striatum with no change in DA. Although the metabolism of catecholamines is a source of oxidative stress, there is little information about DA metabolism and anaesthesia. We assessed the mechanism(s) of enhanced DA metabolism induced by halothane.

METHODS

Microdialysis probes were implanted into male Sprague-Dawley rats and perfused with artificial cerebrospinal fluid (CSF). The dialysate was injected directly into an HPLC every 20 min. Each group of rats (n=5-7) was administered saline, apomorphine 100 microg kg(-1), pargyline 7.5 or 75 mg kg(-1), reserpine 2 mg kg(-1) or alpha-methyl-p-tyrosine (AMPT) 250 mg kg(-1). Another set of rats was perfused with artificial CSF containing tetrodotoxin (TTX) 1 microM or calcium-free CSF containing 10 mM EGTA. Rats were anaesthetized with halothane 0.5 or 1.5% 1 h after pharmacological treatments.

RESULTS

In rats pretreated with apomorphine, despite a decrease in DA concentration, halothane induced a increase in DA metabolites. Pargyline (high dose) and reserpine completely and AMPT partially antagonized the increase in DA metabolites induced by halothane anaesthesia. TTX perfusion reduced the increase in DA, whereas calcium-free CSF perfusion did not.

CONCLUSIONS

Our data suggest that halothane accelerates DA metabolism at presynaptic sites by releasing DA from reserpine-sensitive storage vesicles to the cytoplasm in a calcium-independent manner. The metabolic oxidative stress of inhalation anaesthesia requires future investigation.

Quantitative evaluation of anterior tibial translation during isokinetic motion in knees with anterior cruciate ligament reconstruction using either patellar or hamstring tendon grafts

We studied 79 patients with unilateral injury to the anterior cruciate ligament (ACL). The patients were randomly allocated to reconstruction with autologous patellar bone-tendon-bone (BTB) grafts (49 knees) or hamstring tendon (ST) grafts (30 knees). We measured anterior tibial translation (ATT) during isokinetic concentric contraction exercise 18-20 months after surgery using a computerized electrogoniometer. In both groups the highest ATT during exercise was observed at a knee flexion of about 20 degrees and was 13.5+/-3.0 mm in the BTB group and 13.9+/-3.4 mm in the ST group. There was no difference in the ATT between the reconstructed and healthy knees. For a range of knee flexion between 30 and 50 degrees the ATT in the ST group was significantly higher on the reconstructed side than on the healthy side. In the BTB group, the mean ATT in the reconstructed group was similar to that on the healthy side at a knee flexion angle between 0 and 90 degrees .

Transcriptional regulation of neuronal genes and its effect on neural functions: transcriptional regulation of neuropeptide Y gene by leptin and its effect on feeding

Leptin is an adipose tissue-derived secretory hormone that suppresses appetite by inhibition of neuropepeptide Y (NPY) gene expression in arcuate nucleus (ARC) in the hypothalamus. To investigate the transcriptional regulation of NPY gene by leptin, we carried out a luciferase assay using NPY gene promotor plasmid (NPY-luc) in NPY expressing cells such as N18TG2, NG108-15, and PC12 cells. In these cells, the NPY gene was transactivated by leptin through activation of leptin receptor. Leptin-induced transactivation was mediated through the 221-bp region of the NPY gene promotor, which possesses two putative STAT3 binding sites. To investigate the mechanism of in vivo suppression of NPY gene transcription in ARC by leptin, the effect of SOCS members on the leptin-induced transactivation of NPY gene was studied. In vivo SOCS2 and SOCS3 mRNAs were induced in mouse hypothalamus by leptin. Although leptin (125 ng/ml) induced significant increase in NPY gene transcriptional activity in mock-transfected cells, the leptin-induced NPY gene transcriptional activity was completely abolished in SOCS3-transfected cells. SOCS3 also suppressed the basal NPY gene transcription. These finding suggested that leptin inhibits NPY gene transcription in the hypothalamus in vivo and SOCS3 is a negative regulator of the NPY gene.

Histological and biochemical changes of experimental meniscus tear in the dog knee

BACKGROUND

When degeneration is noted in the meniscus, sutures should not be applied even for a tear of the vascularized region of the meniscus because the meniscus may rerupture after suturing. In this study, the degeneration process of bucket-handle tear of the meniscus was investigated using histological and biochemical markers.

METHODS

A bucket-handle tear in the intercondylar notch was prepared in the dog knee. Eight animals each were killed at 2, 4, 12, 24, and 48 weeks; and changes in the articular cartilage were observed. The cell count and morphology in the meniscus were investigated by hematoxylin and eosin staining, and glycosaminoglycans in the matrix were investigated by toluidine blue staining. Glycosaminoglycans were also measured by high-performance liquid chromatography.

RESULTS

Erosion was noted in the weight-bearing region of the articular cartilage after 12 weeks. The cell count in the meniscus was markedly decreased at 48 weeks. Regarding cell morphology, fibrochondrocytes remained in the meniscus until 12 weeks. The cell morphology varied at 24 weeks, but the number of cells was maintained. Cell proliferation, mainly fibroblasts, was noted from 2 weeks and 4 weeks after surgery in the periphery and body of the meniscus, respectively. Fibrochondrocyte-like cells proliferated from 12 weeks in the meniscal body, and metachromasia was detected by toluidine blue staining, indicating meniscal repair. A marked decrease in glycosaminoglycans was noted at 48 weeks, which was consistent with the decrease in the cell count in the meniscus.

CONCLUSIONS

Early application of sutures is desirable for bucket-handle tear of the meniscus because lesions appear in the cartilage within 12 weeks, but suturing may be performed until 24 weeks because of the absence of obvious meniscal degeneration. However, disorder of the meniscus progresses after 48 weeks and may affect the outcome of the meniscal suture.