Reduced levels of MMP-2 and TIMP-1 in dyssegmental dysplasia.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were measured in a mild case of dyssegmental dysplasia. X-ray pictures of a female baby born vaginally at 39 weeks of gestation showed short, bent, dumbbell-shaped long bones of the limbs and profound dyssegmental ossification in the spine, findings characteristic of dyssegmental dysplasia. When the levels of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured, the levels of MMP-2 and TIMP-1 were significantly reduced. This case might provide a clue to disclose the etiology of dyssegmental dysplasia.     

Delayed sternal closure after cardiac surgery]

Following cardiac surgery, approximation of sternum will produce systemic hypotension or elevation of left atrial and central venous pressures. A new criteria for delayed sternal closure is proposed. Sternal closure has to be delayed when mean left atrial or central venous pressures increased over 2 mmHg at the tentative closure. In seven cases (3.5%) of consecutive 201 patients was delayed the sternal closure under the above mentioned state, all survived and received the successful closure later. One of them died of congestive heart failure four months after the operation and one died of the rupture of the ascending aortic pseudoaneurysm eleven months after the initial operation. Microbiological examination of the mediastinal and pericardial contents obtained at the final sternal closure were negative in all cases. Comparing the total cardiopulmonary bypass time, ventricular fibrillation time, and myocardial ischemic time between in the secondary closure group and in the primary closure group, the total bypass time and the ventricular fibrillation time of the former were significantly longer than the latter, but the ischemic time revealed no difference. In conclusions, persistent elevation of left atrial or central venous pressures after cardiac surgery at the tentative sternal closure seems the reliable predictor for the delayed closure of the sternum. Careful post-operative management prevents serious mediastinal infection. Delayed sternal closure is preferable procedure for the patient with brittle hemodynamics after open heart surgery.     

Endobronchial aspergillosis and actinomycosis associated with broncholithiasis

Endobronchial aspergillosis or actinomycosis associated with broncholithiasis is extremely rare. Here, we describe two cases of endobronchial aspergillosis and actinomycosis associated with broncholithiasis. The patients underwent pulmonary resection due to massive hemoptysis. These cases reveal that a bronchiolith can potentially induce endobronchial fungal or bacterial infection, even in immunocompetent 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.     

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.     

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     

Deposition of complement protein C3b on mixed self-assembled monolayers carrying surface hydroxyl and methyl groups studied by surface plasmon resonance

Since complement activation is recognized as a common response of the host defense system when an artificial medical device is applied to a patient, great effort has been devoted to studies on the interaction of the complement system with artificial materials. However, some uncertainties remain, partially because of the lack of well characterized surfaces and suitable analytic methods for study of the surface phenomena that occur on artificial materials under physiologic conditions. In this study, we employed self-assembled monolayers (SAMs) and the surface plasmon resonance (SPR) technique to study interactions of the serum complement with well characterized surfaces. Self-assembled monolayers carrying various concentrations of hydroxyl groups were prepared using 11-mercapto-1-undecanol (C11-OH) and one of n-nonanethiol, n-dodecanethiol, and n-hexadecanethiol. The amount of NHS deposition on the SAMs increased with increasing C11-OH content of the SAMs, and the amount of anti-C3b antibody immobilization formed on the NHS deposition layers increased with increasing C11-OH content of the SAMs. These results clearly demonstrate that a large amount of C3b, produced through the activation of the complement system, binds covalently to and is adsorbed by hydroxyl-group-rich surfaces. The combination of SAMs and the SPR technique is suitable for studying the interaction of the complement system with solid surfaces, and the results should give basic information needed for a rational design of biocompatible surfaces on synthetic materials.     

A novel synthetic route to poly(β-ketone)s via poly(alkoxyethyne)s

Isopropoxyethyne (1a) and tert-butoxyethyne (1b) were polymerized using group 5 and 6 transition metal catalysts to give poly(isopropoxyethyne) (2a) and poly(tert-butoxyethyne) (2b) , respectively. The weight-average molecular weight (M?_w) of the resulting poly(alkoxyethyne)s was up to 1.0 × 10⁴. Among the transition metal catalysts, a tungsten alkoxide or a molybdenum alkoxide having low Lewis acidity were found to effectively promote the polymerization without causing side reactions. Poly(tert-butoxyethyne) was successfully converted to poly(β-ketone) 3 by acid hydrolysis of the tert-butyl vinyl moiety.