Posterior instability near extension is related to clinical disability in isolated posterior cruciate ligament deficient patients

The purpose of this study is to evaluate the relationship between the magnitude of knee laxity and posterior instability at different knee flexion angles and clinical disability in isolated posterior cruciate ligament (PCL) deficient patients. Knee laxity at 20° and 70° of knee flexion were evaluated using KT-2000 arthrometer, and the posterior instability at 20°, 45° and 90° of flexion were evaluated using stress radiography. We assessed the differences in the knee laxity and the tibial translation between isolated PCL deficient knees and normal knees, and between the patients with giving-way during activities of daily living (ADL) and without giving-way. There were statistical differences in the knee laxity and the tibial translation at all knee flexion angles between the PCL deficient knees and normal knees. The magnitude of the knee laxity at 20° of flexion measured with KT-2000 arthrometer was significantly larger in the patients with giving-way than those in the patients without giving-way although there was no significant difference in the tibial translation at 70° between the two groups. The tibial translation in both medial and lateral compartments at 20° and 45° measured with stress radiography were significantly larger in the patients with giving-way than those in the patients without giving-way although there was not significant difference at 90° between the two groups. These results suggested that the magnitude of the knee laxity and the posterior tibial translation at shallow knee flexion angles would be related to giving-way during ADL in isolated PCL deficient patients.     

Bacterial superantigen enhances cytokine production by T-helper lymphocyte subset-2 cells and modifies glomerular lesions in experimental immunoglobulin a nephropathy

Background The purpose of this study was to examine the effects of bacterial suporantigens, which can derange the immune response and contribute to the renal lesions of immunoglobulin A (lgA) nephropathy. Methods Twenty-five micrograms of a bacterial superantigen, staphylococcal enterotoxin B (SEB), was injected into IgA nephropathy-prone ddY mice intrathymically when they reached 6 weeks of age. Evaluation included measurement of albumin excretion in urine, immunoglobulin concentration, and lymphokine production in vitro, as well as analysis of T-cell receptor expression in splenic T-cell subsets and examination of renal histology by light and fluorescence microscopy. Results At 40 weeks of age, the serum level of IgA in these mice was substantially increased and the number of Vβ8⁺ CD4⁺splenic T-cells was significantly decreased compared with measurements in untreated controls. Both control and SEB-treated mice excreted less than 30 μg/mL of urinary albumin. In mice given SEB, the amount of interleukin 2 (IL-2) and tumor necrosis factor-α (T helper 1 [Th1]-type cytokines) produced by the in vitro-stimulated lymphocytes significantly decreased. whereas that of interleukin 4 (IL-4) and interleukin 6 (IL-6) (Th2-type cytokines) markedly increased compared with measurements in control mice. At 40 weeks of age, mice given SEB showed marked glomerular hypercellularity and enhanced glomerular C3 deposition by renal histology, compared with control mice. Conclusion These results suggest that bacterial superantigen SEB may modify glomerular lesions through activating Th2 cells, while inducing deletion of Th1 cells in this experimental model.     

The relation between EEG and mental development following cardiac surgery performed under simple deep hypothermia in children

In order to assess the accuracy of electroencephalography (EEG), in children who have undergone cardiac surgery under simple deep hypothermia, the relation between IQ or schoolwork achievement and the duration of circulatory arrest was investigated in 75 such children. Abnormal preoperative EEG's were found in 16 per cent of the children while abnormal postoperative EEG's were found in 17 per cent. The children were divided into 4 groups, according to pre- and postoperative EEG results. Schoolwork achievement scores ranged between 3.0 and 3.2, the difference among the groups being insignificant. Moreover, no significant shift in IQ was found among the groups. Finally, regarding the number of children who were able to go on to a higher level of education, including high school the college or university, again no significant differences were found among the 4 groups. In a comparison with the number of such children in neighboring Nagasaki prefecture able to continue on to a higher level of education, no significant differences were seen either. The findings and statistics of this investigation therefore indicate that pre- and postoperative EEG's are not always a reliable reference for assessing the prognosis of cerebral activity.     

Comparison of the size of neuronal and non-neuronal histamine pools in the brain of different rat strains

Summary The size of the neuronal and non-neuronal histamine pools in the brain of three different strains of rats was measured by assuming that the -fluoromethylhistidine-induced maximal decrement of histamine represents the size of the neuronal pool. Although the total histamine levels in the brain showed a considerable interstrain variation, no significant interstrain difference was observed in the neuronal histamine level. These results suggest that the size of the neuronal histamine pool in the brain is relatively stable, whereas the size of the non-neuronal histamine pool is variable.     

Histamine turnover in the brain of morphine-dependent mice

Summary The turnover of brain histamine was examined in mice implanted subcutaneously with a morphine pellet (50 mg free base). The numbers of naloxone-precipitated jumpings and body shakes were maximum 2 and 3 days after implantation, respectively. The brain tele-methylhistamine level significantly increased (50% to 115%) during 12 h3 days after implantation of a morphine pellet, whereas the histamine level remained unchanged. The accumulation of tele-methylhistamine by pargyline treatment was significantly enhanced when pargyline was administered 12 h after implantation, suggesting an enhancement of histamine turnover. However, a similar degree of the tele-methylhistamine accumulation was induced by pargyline during 1–5 days after implantation, as compared with the accumulation in the control mice implanted with a placebo pellet. In mice undergoing morphine withdrawal by either the removal of morphine pellet or the treatment with naloxone 3 days after implantation, the degree of the pargyline-induced telemethylhistamine accumulation or the (S)--fluoromethylhistidine (-FMH)-induced histamine decrease was similar to that observed in the placebo pellet-control mice. The numbers of naloxone-precipitated jumpings and body shakes occurring in mice 3 days after implantation were not significantly affected by any of l-histidine, -FMH or metoprine. These results suggest that turnover of histamine in the brain is enhanced by acute morphine treatment and returns to the normal rate in the stage of chronic treatment and remains unchanged during the state of withdrawal. Send offprint requests to K. Saeki     

Metal ions induce bone-resorbing cytokine production through the redox pathway in synoviocytes and bone marrow macrophages

To evaluate the biological reactions to metal ions potentially released from prosthetic implants, we examined the ability of metal ions to produce bone-resorbing cytokines and the underlying mechanism using synoviocytes and bone marrow (BM) macrophages. The cells were incubated with NiCl(2), CoCl(2), CrCl(3) or Fe(2)(SO(4))(3) at optimal concentrations, which are detectable in joint fluid following total joint arthroplasty. The production of interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha were enhanced by all metal ions tested as determined by enzyme-linked immunosorbent assay. From the results of electrophoresis mobility shift assay, all metal ions enhanced the DNA-binding activity of nuclear factor kappaB (NF-kappaB), and p50-p65 heterodimers and p50 homodimers were the major subunits. These effects of the metal ions were considerably blocked by pyrrolidine dithiocarbamate (PDTC) known as a radical scavenger. An electron spin resonance study clearly demonstrated the ability of metal ions to generate activated oxygen species (AOS), especially hydroxyl radicals (*OH), which accounts for PDTC-blockade of metal ion-induced NF-kappaB activation and subsequent cytokine production. Taken together, our data raised the possibility that small amounts of metal ions released from prosthetic implants activate synoviocytes and BM macrophages through the AOS-mediated process (i.e. the redox pathway), and contribute to the initiation of osteolysis at the bone-implant interface.     

Mitochondrial antigens as targets of cellular and humoral auto-immunity in primary biliary cirrhosis

Several factors point toward an auto-immune pathogenesis for primary biliary cirrhosis (PBC), mostly based on the presence of serum auto-antibodies to mitochondrial antigens (AMAs) and autoreactive T cells (both helper and cytotoxic). Interestingly, epitopes recognized by AMA and T-cell clones are located within overlapping areas of the antigens. Moreover, a role for an imbalance in cytokine pattern and for natural-killer lymphocytes has also been proposed. Despite several experimental reports, no clear evidence is available regarding the interaction of these factors leading to bile duct destruction. This article reviews the current reports regarding the auto-immune reaction against mitochondrial auto-antigens in PBC.     

Histopathological and biochemical studies on pancreatic fibrosis in WBN/Kob rats

 We investigated the time-course of changes in pancreatic fibrosis accompanied with pancreatitis in WBN/Kob rats. The areas of fibrosis and fatty replacement were analysed morphometrically, and biochemical measurements of pancreatic and plasma prolyl hydroxylase and of pancreatic collagenase were assessed. Male rats showed acute pancreatitis at 2–3 months of age, lesions that later underwent a transition to widespread fibrosis. The fibrosis then decreased, and the fibrotic tissue was replaced with adipose tissue. Morphometrically, the fibrotic area reached its maximal size when the rats were 4 months old, diminishing thereafter. The fibrosis occurred mainly in the intralobular space, and was principally attributable to type-III collagen. Type-I collagen scarcely appeared throughout the experimental period. α-Smooth muscle actin appeared in and around myofibroblasts that developed in an early stage and diminished later in accordance with the progressive manner of fibrosis. The plasma prolyl hydroxylase level was higher in males than in females from 4 through 10 months of age. Pancreatic collagenase activity in the males also increased during the same period. These findings suggest that pancreatic fibrosis in male WBN/Kob rats is affected by the balance between prolyl hydroxylase and collagenase. Received: 1 October 1998 / Accepted: 2 October 1998