In Vitro Evaluation of Platelet/Biomaterial Interactions in an Epifluorescent Video Microscopy Combined with a Parallel Plate Flow Cell

Abstract: Suitable evaluation systems are critical for ranking various biomaterials in order to develop a method to design and synthesize nonthrombogenic biomaterials. We have recently developed an in vitro test system to evaluate platelet/biomaterial interactions in whole blood. The system consists of a parallel plate flow cell and epifluorescent video microscopy (EVM). A glass coverslip coated with a polymer was incorporated into the flow cell, and blood was perfused using a syringe pump via a polymer–coated PVC tubing connected to the flow cell. Whole human blood was anticoagulated with heparin (2 U/ml), and the platelets were labeled with the fluorescent dye mepacrine (5 μM). This system permitted real–time and dynamic observations of platelet/biomaterial interactions in whole blood under a defined flow condition. In order to evaluate the feasibility of this system, two different segmented polyether–polyurethanes (SPEUs), PU–PTMG(650) and PU–PTMG(2000), were chosen as test polymers. Surface characteristics verified with electron spectroscopy for chemical analysis (ESCA) and contact angle measurements showed similar results in both SPEUs. Blood was perfused at a wall shear rate of 200 s^–1 for 20 min. Excitation light was applied for 2 s at 1 min intervals. The real–time image was then analyzed at each time point for the percentage of surface area of platelet coverage. Plasma β–thromboglobulin (β–TG) levels were also measured before and after each run. PU–PTMG(650) showed a significantly higher number of adhered platelets than PU–PTMG(2000) at each time point. β–TG levels of PU–PTMG(650) were also higher than those of PU–PTMG(2000), which is comparable to the results of EVM. Thus, this EVM system has been proven to be an excellent and highly sensitive in vitro analytical method for evaluating platelet/biomaterial interactions.     

A comparative study of CHOP therapy and COP-BLAM therapy for non-Hodgkin's lymphoma in elderly patients]

Elderly patients (aged greater than or equal to 65 years) with non-Hodgkin's lymphoma were treated either with CHOP or COP-BLAM therapy, and the effectiveness and reverse effects of COP-BLAM therapy were compared with those of CHOP therapy. Thirty-three patients (aged greater than or equal to 65 years) with previously untreated non-Hodgkin's lymphoma were entered either on CHOP or COP-BLAM regimen between September, 1979 and February 1990. To CHOP therapy was performed in 15 patients (median age; 70 years). Eight of them had diffuse large cell type lymphoma (large), five had diffuse medium-sized cell type (medium) and two had diffuse mixed cell type (mixed). As to clinical stage, there were patients in stage II, 4 in stage III and 9 in stage IV in CHOP group. Of 18 patients (median age; 68 years), who were treated with COP-BLAM therapy, 8 had of large lymphoma and 10 medium lymphomas in histopathological classification. In terms of clinical stage, there were 5 patients in stage II, 4 in stage III and 9 in stage IV. CHOP therapy and COP-BLAM therapy were performed according to the method reported by McKelvey et al, and by Laurence et al., respectively, using the full doses of drugs without consideration the age. Complete remission (CR) was achieved in seven (46.7%) of 15 patients treated with CHOP therapy. In this group, five (38.5%) of 13 patients in advanced stages (stage III or IV) entered CR. Of 18 patients subjected to COP-BLAM therapy, 15 (83.3%) achieved CR. Among 13 patients in advanced stage treated with COP-BLAM therapy, CR was achieved in 11 (84.6%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Crossed cerebellar atrophy following cerebrovascular lesions

A neuroradiological study of crossed cerebellar atrophy (CCA) was performed using X-ray CT in 103 patients suffering from unilateral supratentorial cerebrovascular diseases. CCA was demonstrated in 9 (8.7%) of 103 patients. No difference between the occurrence of CCA in cerebral hemorrhage and that in cerebral infarction was found. CCA was seen in the chronic stage of cerebrovascular disease more than 3 years since stroke occurrence, and was found to be present more frequently and to a greater extent 7 years later. No correlation between the site of bleeding and the occurrence of CCA was found. Trans-synaptic degeneration of the corticopontocerebellar tract was considered in CCA following putaminal and combined hemorrhage involving an internal capsule lesion. However, in thalamic hemorrhage, retrograde degeneration within the cerebellorubrothalamic tract was presumed. CCA following cerebral infarction was seen in patients with massive lesions in the territory of the middle cerebral artery. Multivariate analysis showed that lesions of the parietal and frontal lobes appeared to greatly contribute to the development of CCA. As the degeneration and atrophy in the thalamus on the side of the lesion appeared early and frequently, it was suggested that retrograde degeneration of the cerebellorubrothalamic tract participated, in addition to anterograde corticopontocerebellar tract degeneration, in CCA following middle cerebral artery infarction. It is likely that CCA is caused by both transsynaptic degeneration of the corticopontocerebellar tract and the cerebellorubrothalamic tract.     

Type-II collagen gene expression is transiently upregulated in experimentally induced degeneration of rabbit intervertebral disc

To clarify phenotypic alterations of intervertebral disc cells during the repair process, we cloned partial type-II collagen cDNA from rabbits and analyzed the level of expression of type-II collagen mRNA in disc degeneration. An animal model was created by surgical denucleation of rabbit intervertebral discs through, an extraperitoneal approach. Eight animals each from an experimental and a control group were killed at 2, 4, 8, or 16 weeks postoperatively, and the disc samples were used for this study. Round chondrorcyte-like cells that filled the herniated space showed intense signal of type-II collagen mRNA and significant pericellular immunostaining of type-II collagen but no clear staining of type-I collagen. Northern. blot analysis revealed that the expression of type-II collagen mRNA of the repair disc cells was transiently increased at 4 weeks postoperatively. The cells were able to change their morphology in response to mechanical stimulation by surgical denucleation and to induce a significant increase in the gene expression of type-II collagen at an early phase of disc degeneration. The present results indicate the transient enhancement of repair activity in the degenerative process of injured fibrocartilage.     

Intrathecal administration of N-methyl-D-aspartate receptor antagonist reduces the minimum alveolar anaesthetic concentration of isoflurane in rats

We have studied the effect of intrathecal administration of N-methyl-D- aspartate (NMDA) receptor antagonists on the minimum alveolar anaesthetic concentration (MAC) of isoflurane in rats. In Wistar rats fitted with indwelling intrathecal catheters, we determined the MAC of isoflurane after administration of a competitive NMDA receptor antagonist, APV (0.01, 0.1, 1.0, 10, 30 micrograms), a non-competitive NMDA receptor antagonist, MK801 (0.1, 1.0, 10, 30 micrograms). NMDA (0.01, 0.1, 1.0, 10, 30 micrograms) and saline. APV at all doses except 0.01 micrograms decreased MAC by 17.1-32% (P < 0.001 and P < 0.0001). Although MK801 at 10 and 30 micrograms reduced MAC by 24.3-31.7% (P < 0.001 and P < 0.0001), lower doses did not affect MAC. Intrathecal administration of NMDA reversed these decreases in MAC, but not to control values with APV 10 and 30 micrograms and MK801 30 micrograms. We suspect that NMDA and NMDA receptor antagonists play important roles in the spinal cord in determining the MAC of isoflurane.      

Familial Juvenile Nephronophthisis in Two Siblings — Histological Findings at an Early Stage —

We present two female siblings with familial juvenile nephronophthisis (FJN) which was diagnosed at the early stage of renal failure. Diagnosis was made during the investigation of anemia in case 1 and by a subsequent family survey in case 2. Most patients with FJN are not identified until the terminal stage of renal failure and such cases have rarely been reported in Japan. Case 2 had a reduction in the maximum urinary concentration ability but no azotemia, and among the FJN patients reported in Japan so far she has the least advanced renal disease. Histological examination of the renal biopsy in case 1 showed typical findings of FJN, such as thickening and lamination of the tubular basement membrane (TBM), interstitial fibrosis, and round cell infiltration of the interstitium. In case 2, renal biopsy revealed an irregular marked thickening of the TBM with trivial interstitial changes and a normal glomerular appearance. The histology of these two cases suggests that the TBM may be the primary site affected in FJN.     

Rapid detection of mecA gene by nested PCR for diagnosis of methicillin resistance in Staphylococcus aureus]

In recent years, the most common causative organism of hospital infections has been methicillin resistant Staphylococcus aureus (MRSA). The major mechanism of beta-lactam resistance in MRSA is attributed to the production of a specific penicillin binding protein (PBP2'), which is a product of mecA gene, with extremely low binding affinities to beta-lactams. In the present study, we have established a rapid identification method of MRSA by sensitive detection of mecA gene using nested PCR. Nested PCR method amplifying the target DNA in two steps enhanced the efficiency of the second round amplification. By means of this method, mecA gene was successfully detected in clinical samples, such as blood, pus, sputum and feces within 3-4 hrs. Rapid diagnosis of MRSA-bacteremia is particularly important for prevention of sever systemic infection. There are some strains of S. aureus which possess mecA gene in spite of low minimal inhibitory concentration of DMPPC. In these strains expression of mecA gene is induced by contact of beta-lactams and they obtain methicillin resistance. Using nested PCR method, these latent MRSA are rapidly and certainly detectable. This method should be useful for early and effective detection of MRSA hospital infections.     

Jarcho-Levin Syndrome Associated with Atrial Septal Defect and Partial Anomalous Pulmonary Venous Return: A Case Report

A bstract A 61-year-old woman suffering from Jarcho-Levin syndrome (JLS) was associated with atrial septal defect and partial anomalous pulmonary venous return and underwent corrective surgery. Pressure controlled postoperative ventilator therapy is preferred in patients with JLS.     

Extracardiac Direct Total Cavopulmonary Connection

We report a successful extracardiac direct total cavopulmonary connection without prosthetic materials performed in a 3-year-old boy with tricuspid atresia, infundibular pulmonary stenosis, and normally positioned great arteries. The transected pulmonary trunk was bought down posterolaterally with respect to the right atrium and was anastomosed end-to-end with the inferior vena cava.