Effects of matrix metalloproteinase-9 gene knock-out on the proteolysis of blood-brain barrier and white matter components after cerebral ischemia.

Deleterious processes of extracellular proteolysis may contribute to the progression of tissue damage after acute brain injury. We recently showed that matrix metalloproteinase-9 (MMP-9) knock-out mice were protected against ischemic and traumatic brain injury. In this study, we examined the mechanisms involved by focusing on relevant MMP-9 substrates in blood-brain barrier, matrix, and white matter. MMP-9 knock-out and wild-type mice were subjected to transient focal ischemia. MMP-9 levels increased after ischemia in wild-type brain, with expression primarily present in vascular endothelium. Western blots showed that the blood-brain barrier-associated protein and MMP-9 substrate zonae occludens-1 was degraded after ischemia, but this was reduced in knock-out mice. There were no detectable changes in another blood-brain barrier-associated protein, occludin. Correspondingly, blood-brain barrier disruption assessed via Evans Blue leakage was significantly attenuated in MMP-9 knock-out mice compared with wild types. In white matter, ischemic degradation of the MMP-9 substrate myelin basic protein was significantly reduced in knock-out mice compared with wild types, whereas there was no degradation of other myelin proteins that are not MMP substrates (proteolipid protein and DM20). There were no detectable changes in the ubiquitous structural protein actin or the extracellular matrix protein laminin. Finally, 24 hr lesion volumes were significantly reduced in knock-out mice compared with wild types. These data demonstrate that the protective effects of MMP-9 gene knock-out after transient focal ischemia may be mediated by reduced proteolytic degradation of critical blood-brain barrier and white matter components.

Matrix metalloproteinase 2 gene knockout has no effect on acute brain injury after focal ischemia.

Matrix metalloproteinases (MMPs) may contribute to tissue damage after cerebral ischemia. In this study, wildtype and MMP-2 knockout mice were subjected to permanent and transient (2 h) occlusions of the middle cerebral artery. Gelatin zymography showed that MMP-9 levels were increased in all brains after ischemia. MMP-2 levels did not show a significant increase in wildtype mice, and were not detectable in knockout mice. Laser doppler flowmetry demonstrated equivalent ischemic reductions in perfusion in wildtype and knockout mice. In both permanent and transient occlusion paradigms, there were no statistically significant differences between wildtype and knockout mice in terms of 24 h ischemic lesion volumes. These data suggest that MMP-2 does not contribute to acute tissue damage in this model of focal ischemia.

Protective effects of pamiteplase, a modified t-PA, in a rat model of embolic stroke.

The effects of alteplase (tissue plasminogen activator, t-PA) and pamiteplase (a modified t-PA with longer half-life and increased potency) were compared in a clinically relevant model of embolic stroke. Rats were treated with pamiteplase (0.5 mg/kg or 1 mg/kg bolus), alteplase (10 mg/kg infusion) or normal saline. Pamiteplase (1 mg/kg) was as effective as alteplase in reducing 24 h brain infarct volumes, neurological deficit scores and residual clot grades. Cerebral blood flow recovery at 30 min after thrombolytic treatment was partial and did not correlate with 24 h infarct volumes or neurological deficits. However, there was good correlation between 24 h residual clot grades and infarct volumes, suggesting a delayed timeframe for pamiteplase- and alteplase-induced reperfusion.

Serum protease inhibitor capacity for elastase and the severity of pancreatitis.

To clarify the relationship between the diminution of the serum protease inhibitor capacity and the severity of pancreatitis, the binding capacity of serum protease inhibitors for exogenous elastase 1 (E1) was investigated by gel filtration, the elastase activity of the alpha 2-macroglobulin (alpha 2-M)-elastase complex was measured, and the relationship between these findings and the severity of pancreatitis was studied in 13 patients with pancreatic disease and 6 healthy subjects. When 125I-labeled E1 was added to the sera of healthy subjects, it bound to alpha 2-M and alpha 1-protease inhibitor (alpha 1-PI) with a mean ratio of 72:28. In mild acute pancreatitis (n = 5), the binding capacity of alpha 2-M was less than that in healthy subjects. In severe pancreatitis (n = 4), most of the exogenous E1 bound to alpha 1-PI (alpha 2-M vs. alpha 1-PI, 13:87). This diminution in the binding capacity of alpha 2-M correlated well with the severity of acute pancreatitis. In the sera of patients (n = 4) with pancreatic cancer containing much immunoreactive E1, the proportion of exogenous E1 bound by alpha 2-M and alpha 1-PI (25:75) was similar to that seen in severe acute pancreatitis. A significant inverse relationship between the binding capacity of alpha 2-M and the activity of the endogenous elastase bound to alpha 2-M was seen in various pancreatic diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of local pancreatic blood flow in development of hemorrhagic pancreatitis induced by stress in rats.

Our previous data showed that the pancreatitis induced in rats by cerulein develops into hemorrhagic pancreatitis following water-immersion stress. The present study examined the effects of water-immersion stress and high doses of cerulein (intraperitoneal injection) on pancreatic blood flow. Five hours of water-immersion stress reduced the local pancreatic blood flow to approximately 30% of the initial value (253.75 +/- 12.58 ml/min/100 g) without causing any histological alterations. Blood flow was decreased as early as 1 h after the immersion and reached the lowest value (30% of initial value) 3 h after the immersion. The administration of 40 micrograms/kg body wt cerulein as two intraperitoneal injections reduced the pancreatic blood flow by 40% 5 h after the first cerulein injection. The injections of cerulein combined with water-immersion stress did not reduce the pancreatic blood flow more than did water-immersion stress alone. The systemic blood pressure was unaffected during 5 h of water immersion after the cerulein injections. These findings suggest that in rats the stress-induced decrease of local pancreatic blood flow may not produce pancreatitis, but may aggravate an existing acute pancreatitis.

Acute pancreatitis induced by cyclosporin A under stimulation of pancreas by caerulein.

Our purpose was to investigate enzymatically and morphologically the acute effect of the immunosuppressive agent cyclosporin A (CsA) on the exocrine pancreas of rats. The intravenous injection of CsA 10 and 20 mg/kg body weight (BW) increased the content of pancreatic amylase and protein and decreased the content of pancreatic DNA. Histologically, we observed intraacinar vacuolization and individual cell necrosis. Under stimulation of the pancreas by two intraperitoneal injections of caerulein 5 micrograms/kg BW at 1-h intervals (which did not induce any evident change in the pancreas), CsA induced a significant increase in serum amylase and in pancreatic wet weight in a dose-dependent manner. CsA at doses of 10 and 20 mg/kg BW produced a significant increase in the content of pancreatic amylase and protein. Macroscopically, we observed marked pancreatic edema, venous dilatation, and patchy hemorrhage. Histologically, there were significant differences in the severity of intra-acinar vacuolization, interstitial edema, neutrophil infiltration, individual cell necrosis, and hemorrhage, severity of which was dose dependent. Pancreatic ductal erosion was particularly marked following treatment with CsA 20 mg/kg BW. These findings indicate that CsA accelerates abnormal pancreatic enzyme secretion and suggest that the therapeutically recommended doses of CsA can induce acute pancreatitis under stimulation of the pancreas.

Horseshoe anomaly of the pancreas.

A 72-year-old man with recurrent pancreatitis and a horseshoe-shaped anomaly of the pancreas is described. The diagnosis was made by endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography scan; laparotomy was confirmatory. The abnormal duct branched to the lower left from an enlarged Santorini's duct; a thin Wirsung's duct was joined at its distal portion to the junction of the abnormal duct. The anomaly was associated with a cystic dilatation of the common bile duct with stone and cholecystolithiasis. This anomaly is considered to be a variation of the dominant dorsal duct syndrome.

A possible role of VEGF in osteolytic bone metastasis of hepatocellular carcinoma.

The incidence of bone metastasis was around 13% in 404 patients with hepatocellular carcinoma (HCC) who underwent treatment at the National Kyushu Cancer Center between 1988-97, which is a high value among various cancers. This is, in part, due to the prolonged survival time of HCC patients in recent years. Serum vascular endothelial growth factor (VEGF) levels were significantly elevated in HCC patients with bone metastases as compared to those in patients with liver cirrhosis/chronic hepatitis and HCC patients without bone metastasis. VEGF was positively stained in both the primary lesion and bone metastasis of HCC by immunohistochemistry. In the process of bone metastasis, an increase in bone resorption is a crucial step prior to invasion of the bone. VEGF, the most important angiogenic factor, has been shown to stimulate bone resorption through its effects on osteoclasts. Thus, HCC cells reach the bone marrow space, and then secrete VEGF which facilitates osteolytic bone metastasis. VEGF may also facilitate tumor growth in the bone by acting as an angiogenic factor once invasion of the bone is complete. This might be another reason for the high incidence of bone metastasis in HCC.

[A clinical evaluation of doxycycline in the treatment of genitourinary infections caused by Chlamydia trachomatis].

The clinical effectiveness of doxycycline (DOXY) in the treatment of chlamydial infections was studied by giving it to 14 patients composed of 9 with nongonorrheal urethritis and 5 with cervicitis, all caused by Chlamydia trachomatis. DOXY was given in an oral dose of 100 mg twice daily for 4 to 19 days. The total dosage ranged from 800 to 3,800 mg. The overall clinical efficacy as assessed on the basis of both bacterial response and relief of subjective or objective symptoms was excellent in all of 12 evaluable patients. Two patients for whom we failed to perform postdose bacteriological examinations were excluded from evaluation. No side effect related to dosing of DOXY developed.

[A case of neurofibromatosis type 1 associated with arteriovenous fistula caused by re-bleeding of a vertebral dissecting aneurysm].

We described a dissecting aneurysm of the vertebral artery (VA), which was associated with neurofibromatosis type 1 (NF1). A 41-year-old man was referred to our hospital because of abrupt, severe headache. A CT scan revealed diffuse subarachnoid hemorrhage (SAH) predominantly in the prepontine cistern. The angiograms showed a string sign in the left VA, just distal to the posterior inferior cerebellar artery (PICA). The vertebral dissection was considered responsible for SAH, and endovascular occlusion of the left VA was attempted. During the intervention, the patient complained of severe neck pain at the time of selective vertebral angiography, which revealed an arteriovenous fistula. The VA was occluded proximal to the PICA with GDC, which covered the fistula. Open surgery confirmed the two unruptured aneurysms. Intracranial dissection is rarely reported in association with NF1. However, ateriovenous fistula is not an uncommon combination with dissecting aneurysm and the extracranial segment of the VA is a characteristic target. Anatomical feasibility is conceivably the pathogenesis.

[Efficacy of a latex Foley catheter with sustained release of chlorhexidine: 1st report: Clinical trials for the prevention of urinary tract infection].

Seventy five patients requiring urethral catheterization for over 24 hours were treated with a latex Foley catheter with sustained release of chlorhexidine in a closed drainage system. While the catheter was indwelling, urinary concentrations of chlorhexidine were maintained at the level of 1 to 2 micrograms/ml in average in almost all patients. The catheter was highly effective in preventing the acquisition of catheter-associated bacteriuria in patients with initially sterile urine without systemic antimicrobial therapy. The acquisition rate of bacteriuria was 8, 16, 23, 35 and 74% on day 3, 4, 5, 6 and 7 with the catheter indwelling, respectively. The catheter was not effective in eradicating preexisting bacteriuria. Complications of the catheter were minimal.

[Clinical studies of antimicrobial prophylaxis of recurrent urinary infection in women. Long-term, low-dose pipemidic acid for prophylaxis].

The prophylactic efficacy of long-term, low-dose antimicrobial treatment in urinary tract infection (UTI) was studied. Fifty-eight female adult patients with a history of at least two recurrent episodes of UTI in the past year were entered into this study, and the prophylactic regimen was not started until the existing UTI had been eradicated. Patients took 250 mg of pipemidic acid (PPA) daily at bedtime after voiding for 6 consecutive months. Incidence of recurrence of UTI in 48 patients with uncomplicated UTI and 10 patients with complicated UTI decreased to 0.15 and 0.29 per year, respectively, during the treatment compared with 3.5 per year before the treatment. At the end of the 6 months of prophylactic treatment, the patients were divided into two groups by the envelope method. Seventeen patients were treated for a further 6 months and 11 patients were followed up without further medication. Prophylactic efficacy of UTI was obtained in both groups, and there was no significant difference in the incidence of recurrence between the two groups. These findings suggest that the 6-month period of prophylaxis might be sufficient. Examination of the periurethral swab showed that E. coli and Klebsiella sp. were decreased during the treatment. This prophylactic treatment produced no resistant strains. Urinary levels of PPA in the morning urine of patients administered 250 mg of PPA at bedtime averaged 513 micrograms/ml. These values were about 2 times higher than those found in the evening urine after administration of the same dose in the morning.

[The usefulness of Chlamydia testpack for the diagnosis of Chlamydia trachomatis infection in genito-urinary tract].

A comparative study between Chlamydia Testpack and Chlamydiazyme for the detection of chlamydial antigen was performed. In 61 cases suspected of being chlamydial infection, Chlamydia Testpack had a specificity of 92% and a sensitivity of 88% when compared with Chlamydiazyme. On the result of study using Chlamydia trachomatis serotype B, the sensitivity of Chlamydia Testpack which had a lower limit of 6 x 10(4)/ml of EB was less than that of Chlamydiazyme which had a lower limit of 0.7 x 10(4). However, the large number of EB presented in almost all positive specimen, indicated that Chlamydia Testpack could be used to screen the clinical materials.

[Adult T-cell leukemia with vertebral bone tumor and acute transverse myelopathy].

We describe a case of adult T-cell leukemia (ATL) with vertebral bone invasion, who developed acute paraplegia and responded well to irradiation and combined chemotherapy. A 36-year-old man born in Tsushima Island was admitted to our hospital in May 1987, because of a sudden onset of paraplegia, hypesthesia below the level of 7th thoracic vertebra and vesicorectal disturbance. The white blood cell count was 9,500/microliter with 16% of abnormal lymphocytes showing lobulated nuclei. The surface marker analysis revealed that CD3, CD4, CD8 and CD25 positive cells were 88.1, 83.9, 6.4 and 1.3% of the peripheral mononuclear cells, respectively. Anti-ATLA antibody was positive. Serum calcium level was elevated. Bone scintigraphy showed multiple vertebral bone lesions. Vertebral bone mass and a compressed spinal cord in the 7th thoracic level were confirmed by CT scanning and MR imaging. Cerebral spinal fluid was negative for tumor cells. A diagnosis of ATL was made. Irradiation and combination chemotherapy improved bone lesions and neurological signs and the disease was well controlled by maintenance chemotherapy up to the present (August, 1988).

Characteristic behavior of serum elastase 1 in pancreatic cancer.

Diagnostic significance of serum immunoreactive elastase 1 (IRE) in pancreatic cancer was evaluated in 53 patients with pancreatic cancer. Frequency of abnormally high serum IRE levels in pancreatic cancer was 66.0%; 87.0% in head cancer (N = 23), 55.0% in body & tail cancer (N = 20) and 40% in diffuse cancer (N = 10). Serum IRE level in resectable cancer was significantly higher than that in unresectable cancer. Comparative studies of serum pancreatic enzymes revealed that serum IRE was the most sensitive marker for diagnosis of pancreatic cancer. The characteristic behavior of serum IRE throughout the course of pancreatic cancer was that abnormally high levels of IRE are maintained for a longer period of time when compared to that of pancreatitis. In the comparative study of serum IRE and CA19-9, of the 9 cases of pancreatic cancer with CA19-9 levels less than 100U/ml, 7 showed abnormally high values of IRE, and of these 4 were resectable. These results indicate that in order to detect early pancreatic cancer, any elevation of serum IRE before CA19-9 increase should be noted with care, and patients who particularly show elevated IRE values for more than one month should be subjected to more extensive morphological examinations.

Study of a Pd-Ag-Sb system alloy for metal-ceramics.

The present study is aimed at developing a palladium silver based alloy containing antimony and other elements for metal-ceramics. Composition 54.2Pd-36.2Ag-4.7Sb-2.9In-1.0Sn-1.0Ga++ + (alloy No. 10) was finally selected as the best for practical applications. Liquidus and solidus temperatures of this alloy were 1,250 degrees C and 1,087 degrees C. Under fired conditions, the Vickers hardness number, tensile strength, and elongation were 270, 647 MPa, and 3.4%, respectively. In the temperature range from 20 degrees C to 600 degrees C, the thermal expansion rate was 0.87%, and the thermal expansion coefficient was 15.0 X 10(-6)/degrees C. The mechanical and manipulation properties of this alloy were satisfactory for clinical applications.

Evaluation of dimensional stability of elastomeric impression materials during disinfection.

Disinfection of impression materials is recommended for preventing cross-contamination in dental clinics. However, aspects of the evaluation of elastomeric impression materials only slightly subjected to the effects of disinfectants have not been established. Therefore, the effects of sodium hypochlorite, glutaral, iodine, and ethanol disinfectants on elastomeric impression materials, condensation silicone, polysulfide, addition-type silicone (vinyl silicone), hydrophilic vinyl silicone, and polyether, were evaluated directly in a time-dependent manner by a non-contact displacement meter. Condensation silicone impression materials and polysulfide rubber impression materials greatly shrank over time, but their shrinkage decreased with immersion in disinfectants. Vinyl silicone impression materials and polyether impression materials showed excellent dimensional stability in air. However, hydrophilic vinyl silicone impression materials and polyether impression materials expanded greatly when immersed in disinfectants, especially when immersed in ethanol. Hydrophobic vinyl silicone impression materials showed excellent dimensional stability regardless of the presence or absence of disinfectants.

Properties of hydroxyapatite-coated Ti-6Al-4V alloy produced by the ion-plating method.

To improvement the brittleness of hydroxyapatite (HAp) coated on titanium alloy (Ti-6Al-4V), a thin ceramic layer was formed by means of the RF ion-plating method. The alloy substrates were coated with HAp at 1, 3 or 5 microns thickness and heat-treated at 500 degrees C for 4 hours. Properties of HAp-coated alloy were evaluated by characterization of the ceramic films both before and after heat-treatment, as well as by bending, electrochemical and dissolution tests. HAp-coated film had a slightly higher Ca/P ratio than the original material and was stoichiometrically Ca10(PO4)6(OH)2 by EPMA analysis. HAp was mainly recognized crystallographically by XRD analysis of the films after heat treatment, though it was hardly recognized on before heat-treatment film. These coated materials had a residual strain ranging from 0.3 to 0.7% without causing cracks in the HAp films with the three-point bend testing. Electrochemically, it was confirmed that the corrosion resistance of the Ti alloy was improved by any coating process. The amounts of Ca released from HAp coated film in 0.9% NaCl solution tended to increase with films that were 3 and 5 microns in thickness, but there were no significant differences in Ca released from film before and after heat treatment.

The pattern design for evaluation of castability of nickel-chromium alloys.

To find a pattern design that would provide a higher degree of discrimination for castability of nickel-chromium alloys using a polyester sieve cloth pattern, four shaped patterns were chosen. The results as calculated by t-test indicated that patterns No. 2 and No. 3 can discriminate the castability of nickel-chromium alloys over almost the total range of the casting temperatures, but that pattern No. 3 is a better discriminator for the castability. Pattern No. 1 can only discriminate the castability at lower casting temperatures. Pattern No. 4 can only discriminate the castability at higher casting temperatures. The percent castability value calculated from the number of complete square segments and the areas of the four patterns are highly linear correlations, so it is reasonably accurate to calculate the castability only from counting the number of complete square segments. Beryllium-containing nickel-chromium alloy is more castable than non-beryllium-containing alloy and the higher casting temperatures appear to result in better castability.

A study of the method of making dental prosthetic appliances by sintered titanium alloys: effect of copper powder content on properties of sintered titanium alloy.

The effects of added copper powder to the properties of the sintered titanium alloys were investigated by measuring the compressive strength and densities of the green and sintered compacts, the thermal expansion curves and dimensional changes in the sintered compacts, and the accuracy of the crown-type restorations. The compressive strengths of green compacts ranged from 55 to 75 MPa. The expansion of green compacts increased with increased copper content. The sintered density was lower than the green density. The compressive yield strength of sintered compacts ranged from 260 MPa to 410 MPa. The sintered compacts expanded from 0.35% to 1.03% and the expansion increased with increased copper content. The dimensional accuracy of crown-type restorations showed the same dimensional change tendencies as did the sintered compacts. These results showed that the fit and the strength of sintered titanium alloy restorations could be improved.