Fatigue resistance of composite restorations: effect of filler content

OBJECTIVES

The purpose of this study was to evaluate the effects of filler level on the fatigue impact resistance of resin composite.

METHODS

A series of experimental composite materials was prepared by incorporating a silanized quartz filler (3-5 microns in size) into a light-cured resin matrix of Bis-GMA/TEGDMA. The filler contents in the experimental composites varied from 40 to 85 wt%. The composites were placed in standardized Class I cavities prepared in bovine teeth. The specimens were stressed with a repetitive impact load (1.6 x 10(2) joule) with loading cycles ranging from 50,000 to 150,000 times. The cracks induced by cyclic loading were observed on the sectioned surfaces of the tested specimens.

RESULTS

The composites with considerably low or high filler content (< 60% or > 80% by weight) were significantly low in fatigue resistance. The results revealed that an inverse linear relationship tended to exist between filler level and fatigue resistance of the composite materials beyond a certain level of filler content.

SIGNIFICANCE

Increased filler level does not necessarily improve the fatigue resistance of a resin composite as determined by applying a repetitive impact load.

Intestinal protein loss and bleeding assessed by fecal hemoglobin, transferrin, albumin, and alpha-1-antitrypsin levels in patients with colorectal diseases

Four fecal proteins (hemoglobin, transferrin, albumin, and alpha 1-antitrypsin) were measured by enzyme-linked immunosorbent assay (ELISA) in patients with colorectal diseases. Levels of all 4 proteins were significantly increased in patients with colonic cancer and ulcerative colitis (UC) compared to levels in control subjects, while fecal alpha 1-antitrypsin was particularly elevated in colonic Crohn's disease (CD). That is, the fecal protein pattern of CD was distinct from those of colonic polyps, colonic cancer, and UC. To investigate whether levels of these fecal proteins reflect disease activity in UC and CD, comparative evaluation of fecal proteins in the active and inactive phases was performed. In UC, differences in the fecal concentrations of all 4 proteins were significant between the active and inactive phases of the disease. In CD, however, the difference in alpha 1-antitrypsin concentration was significant. Our results suggest that measurements of these 4 fecal proteins would be useful in the screening of colorectal diseases. In addition, these markers can also be used as indicators of disease activity in inflammatory bowel diseases.

Reliable and sensitive method for determination of microcystins in complicated matrices by frit-fast atom bombardment liquid chromatography/mass spectrometry

A reliable and sensitive method for determination of hepatotoxic microcystins in complicated matrices by frit-fast atom bombardment liquid chromatography/mass spectrometry (Frit-FAB LC/MS) is described. Immonium ions of constituent amino acids, which were obtained together with molecular ion species by FAB mass spectral analysis of standard microcystins RR, YR, LR, and [D-Asp3] and [Dha7]microcystins LR using flow injection system composed of Frit-FAB probe, showed potential for reliable identification of microcystins by Frit-FAB LC/MS. Frit-FAB LC/MS using a microbore column provided not only the baseline separation of standard microcystins RR, YR, and LR but 200-fold higher sensitivity than that using conventional column. Furthermore, when a selected ion monitoring (SIM) technique was used, the detection limits of microcystins RR, YR, and LR were 300, 350, and 400 pg, respectively, at a signal-to-noise ratio of 5:1, and calibration curves of each microcystin showed a linear relationship from 2 ng to 50 ng. Finally, identification and quantitative analyses of microcystins in water samples were carried out.

Amino acids and peptides. XXXIX. Synthesis of iNoc-Gln-Val-Val-Ala-Ala-pNA and its action on thiol proteinases

Based on the results of X-ray analysis of the complex between Suc-Gln-Val-Val-Ala-Ala-pNA, a fairly potent thiol proteinase inhibitor, and papain, iNoc-Gln-Val-Val-Ala-Ala-pNA was designed and prepared and its inhibitory activity against thiol proteinases was examined. iNoc-Gln-Val-Val-Ala-Ala-pNA inhibited cathepsin L fairly specifically, although its potency is not high.

Clinical significance of plasma endothelin-1 in patients with chronic liver disease

To determine the clinical significance of plasma endothelin-1 in chronic liver disease, these levels were measured by radioimmunoassay. The plasma endothelin-1 levels in patients with cirrhosis (N = 16) (2.04 +/- 0.25 pg/ml) and patients with hepatocellular carcinoma (N = 22) (2.23 +/- 0.17 pg/ml) increased significantly compared with controls (N = 16) (1.17 +/- 0.17 pg/ml) and patients with chronic hepatitis (N = 11) (1.09 +/- 0.19 pg/ml) (P < 0.01). The presence of ascites rather than tumor volume was associated with a significant elevation of endothelin-1. Endothelin-1 showed significant negative correlations with parameters of hepatic function, including indocyanine green clearance, serum albumin, and prothrombin time. Although endothelin-1 was not correlated with plasma renin activity and plasma endotoxin, it demonstrated a significant positive correlation with the plasma level of atrial natriuretic peptide (r = 0.42, P < 0.01). These findings demonstrate that plasma endothelin-1 increased in proportion to the severity of liver damage and may be causally related with the derangement of systemic/renal hemodynamics and fluid and electrolyte homeostasis seen in advanced liver disease.

[An autopsy case of Sjögren syndrome with organized and fresh subdural hemorrhage (hematoma)]

An autopsy case of Sjögren syndrome with organized and fresh subdural hemorrhages (hematoma) is reported. A 49-year-old woman who had been suffering from Sjögren syndrome had gradually lost her consciousness and was taken to the hospital where she died several hours later. Subsequently a doctor found the subdural hematoma of unknown origin on her Brain CT. At autopsy, her skin was dry and all of her teeth were missing. There were sporadic cutaneous purpura and subcutaneous hemorrhages in her trunk and limbs. The histopathological examination revealed that the submandibular gland had no normal acini, and was replaced by fibrous and adipose tissues with numerous lymphocytes. There were signs of fibrosis with inflammation in her liver, kidneys and lungs. The thyroid gland showed thyroiditis. Serological findings showed a significant high level of antinuclear antibody, positive RA factor and high gamma-globulinemia. The autopsy revealed that her cause of death was acute subdural hematoma and uncal herniation. There were no external injuries on her head or face. It is suggested that her acute subdural hematoma according to the hemorrhagic tendency, affected by her Sjögren syndrome.

Ultrastructural localization of retinal guanylate cyclase in human and monkey retinas

Immuno-imaging with confocal and electron microscopy revealed the localization of retinal guanylate cyclase (RetGC) in human and monkey retinas. Using an antibody against a peptide derived from human RetGC, RetGC was found predominantly in the photoreceptor layer in these retinas, although a small amount of RetGC was detected in various other retinal cells. In particular, the cone outer segments were more densely labeled with the antibody than the rod outer segments. The RetGC in outer segments was localized exclusively in the membrane-rich domains, and appeared to be associated with the marginal region of the disk membrane and/or the plasma membrane. The connecting cilium and its cytoplasmic extension never showed immunoreactivity with the antibody. The localization of RetGC in photoreceptor cells is discussed from the viewpoint of mechanisms for the recovery of photoreceptors to the dark level.

Radiation therapy for esophageal cancer in patients over 80 years old

PURPOSE

A retrospective analysis was performed to investigate the treatment outcome and the significance of radiation therapy for esophageal cancer in patients over 80 years old.

METHODS AND MATERIALS

Between 1971 and 1990, 257 patients with squamous cell carcinoma of the esophagus were treated by radiation therapy. Of these, 40 patients over eighty years old were investigated. The reasons for radiation therapy were advanced age alone in 22 patients, Stage IV disease in 13, and medical problems in 5. Of these, 33 patients (83%) could be irradiated over 60 Gy. The cases with Stage I to III disease who received 60 Gy or more were defined as the curative radiation therapy group, and the others were defined as the palliative radiation therapy group. Actuarial survival rates were determined by the Kaplan-Meier method.

RESULTS

The 5-year disease-specific survival rate for the curative radiation therapy group (n = 25) was 34% with three intercurrent deaths. None of the patients in the palliative radiation therapy group (n = 15), including 13 cases with Stage IV and two given-up cases, survived over 2 years. No severe radiation damage was observed in either group. The 5-year disease-specific survival rate was 64% for complete response cases of local response, and 8% for partial response and no change cases (p < 0.01). The 5-year disease-specific survival rate was 64% for the patients with tumors less than 5 cm in length, and 8% for the patients with tumors over 5 cm in length (p < 0.001). No significant survival differences were found in regard to sex and tumor location. The patients with superficial spreading type and polypoid type tumors according to the radiologic findings had better prognoses than the patients with ulcerative type and circumferential type tumors.

CONCLUSIONS

Radiation therapy is a safe and effective treatment for esophageal cancer in patients over 80 years old.

p53 proteins accumulated by heat stress associate with heat shock proteins HSP72/HSC73 in human glioblastoma cell lines

We investigated the accumulation of p53 proteins after heat stress and their association with HSP72/HSC73 using four human glioblastoma cell lines. Human glioblastoma cell lines U-87MG and A-172 exhibited no mutation in the region between the 2nd and 11th exons of the p53 gene, whereas A-7 and T98G had mutations in exon 5 and exon 7 of the p53 gene, respectively. In U-87MG and A-172, the levels of wild-type p53 protein were slightly increased by heat stress. Levels of mutant p53 protein were apparently increased by heat stress in A-7, but not in T98G. Furthermore, wild-type p53 proteins in both U-87MG and A-172 co-immunoprecipitated with anti-HSP72/HSC73 antibody and HSP72 and HSC73 in them co-immunoprecipitated with anti-p53 antibody as did the mutant p53 proteins. These findings suggest that p53 proteins accumulated by heat stress are associated with HSP72 and HSC73.

Effects of chronic treatment with clofibric acid on response of rat hepatocytes to mitogenic stimuli

Mitoinhibitory effects of clofibric acid (CA) were investigated in rat hepatocytes in vitro and in vivo. Female Sprague-Dawley rats, 11 weeks of age, were dietetically treated with CA at 9000 ppm for up to 13 weeks. In the in vitro study, hepatocytes were isolated from rats on day 4 and in weeks 1, 2, 5, 9 and 13, and cultured for 48 h in a medium containing epidermal growth factor. Over the last 24 h, bromodeoxyuridine (BrdU) was added to the medium to determine number of hepatocytes in S-phase. The labeling index (LI) of CA-treated hepatocytes in culture was below control values as early as day 4, and progressively declined with increasing treatment period. In the in vivo study, rats were 2/3 partially hepatectomized at week 13 and maintained for 24 h. BrdU was injected intraperitoneally 1 h prior to necropsy. The LI in the CA-treated liver was also decreased. These data indicated that continuous treatment of CA resulted in decreases in hepatocyte response to growth stimuli, and suggested a possible relation between the chronic growth inhibitory effect on cell multiplication and tumor promotion in rat hepatocarcinogenesis.

[Deterioration of liver function following endoscopic injection sclerotherapy of esophageal varices--significance of a new index for liver function "delta TB"]

Changes of liver functions associated with endoscopic injection sclerotherapy (EIS) in which less than 6 ml of 5% ethanolamin oleate was used were investigated in 50 patients with remarkable esophageal varices. The index used for evaluating hepatic reserve was the difference of total bilirubin in serum between immediately and 15 hours after EIS and was tentatively named as "delta TB" (normal range < or = 0.1). In the patients classified as Child-Pugh A (n = 25), Child-Pugh B (n = 19) and Child-Pugh C (n = 6), delta TB was 0.04 +/- 0.30, 0.23 +/- 0.41, and 0.54 +/- 0.21, respectively. One month after the entire sessions of EIS, the changes of liver function tests before and after EIS were compared in 45 cases. It was disclosed that delta TB was elevated in parallel with the severity of their liver dysfunction before EIS. Also, delta TB seems to reflect the prognosis of the patients treated by EIS for some extent, since the survival period of the cases treated by EIS were correlative with delta TB (r = -0.734, p < 0.01), and delta TB of 20 cases who survived for longer than 5 years after EIS was 0.04 +/- 0.32. Therefore, delta TB seems to be a useful marker for estimating the influence of EIS on liver function.

[A case of sarcoidosis with systemic lymph node involvement presenting as multiple high-density masses on chest and abdominal CT]

We report a case of sarcoidosis with mediastinal and abdominal lymph node involvement presenting as multiple high-density masses on chest and abdominal CT. The patient was a 43-year-old housewife who came to our hospital because of a dry cough and exertional dyspnea. A chest radiograph showed bilateral diffuse reticulo-nodular shadows and widening of the mediastinum. On CT of the chest and the abdomen, lymph nodes were swollen throughout the mediastinum and the para-aortic area of the abdomen. They appeared as very-high-density masses on plain CT. Bronchoscopy revealed involvement of the bronchial walls. Punch biopsy of the bronchial wall, TBLB, and biopsy of the anterior mediastinal lymph node all revealed non-caseous epithelioid cell granulomas. These granulomas contained lamellated, irregularly shaped and darkly-stained structures (Schaumann bodies) that caused the high density of the involved lymph nodes on CT. This case shows at least a part of the mechanism of calcification of lymph node lesions in patients with sarcoidosis.

[The effect of subcutaneous administration of buprenorphine with patient controlled analgesia system for post-operative pain relief]

We conducted a study comparing patients receiving continuous subcutaneous administration of analgesia with self controlled analgesia system (CSAA group) with those receiving continuous epidural infusion (Epi group) for postoperative analgesia after abdominal surgery. Fourteen patients were randomized into two groups: CSAA group (n = 7) received 20 micrograms.h-1 of buprenorphine (Bu) subcutaneously with additional 20 micrograms of Bu using Baxter infusor BB+PCA; Epg group (n = 7) received continuous epidural infusion of 0.4 mg of Bu and 46 ml of 0.25% bupivacaine daily (16.7 micrograms.h-1 of Bu) using Baxter infusor 2 ml.h-1 type. In both groups, patients received supplemental 0.1 mg of Bu subcutaneously as needed. During 48-hour postoperatively, verbal descriptor pain scale, sedative scale, visual analogue scale, supplemental doses of Bu, and side effects were evaluated. There was no significant difference of verbal descriptor pain scale, sedative scale, visual analogue scale, and supplemental doses of Bu between CSAA group and Epi group. Total doses of Bu during the first 12 hours postoperatively (CSAA group: 0.37 +/- 0.08 mg, Epi group: 0.30 +/- 0.08 mg) were significantly more than those during other 12-hour period in both groups (P < 0.05). There was no severe side effect in both groups. We conclude that continuous subcutaneous administration of analgesic was effective for postoperative analgesia, and almost the same analgesic effect was obtained as compared with continuous epidural analgesia. We calculated that the adequate dose of Bu subcutaneously during early postoperative period to be about 30 micrograms.h-1 of Bu.

Immunohistological investigations of autopsied carotid bodies and their application to diagnosing strangulation

Using immunohistochemical staining, the histological changes and the presence of neuropeptides (enkephalin and VIP) in the carotid body have been investigated in medico-legal autopsy cases, especially asphyxia cases. Only in cases of manual and/or ligature strangulation cases that sustained a force near the carotid body, were the chief cells mainly lightly stained, indicating that they had been "active" cells. Furthermore, these cells and their nuclei were enlarged in comparison to the chief carotid body cells in other autopsy groups. It was thus felt that these changes had resulted from the force that had directly affected the carotid body. Based on these findings, it was concluded that immunohistochemical investigation of the carotid body offers a useful possibility for diagnosing manual asphyxia, especially in autopsy cases involving strangulation.

Restriction fragment length polymorphism (RFLP) of genomic DNA of Moraxella (Branhamella) catarrhalis isolates in a hospital

Epidemiological typing, based on restriction fragment length polymorphism (RFLP) by pulsed-field gel electrophoresis (PFGE), was attempted for the 38 clinical isolates of Moraxella catarrhalis obtained at Shinshu University Hospital during the years 1987 and 1993. Digestion with SmaI or NotI generated well separable, 12 to 5 genomic DNA fragments ranging from 1,000 kb to 30 kb and the strains could be classified into 14 or 13 types, respectively. The electrophoretic profile differed with the strain in most of them and was hence useful to distinguish the each strain. Investigation for their RFLP have, however, suggested that majority of them, including the type strain ATCC25238, may have derived from a common ancestor.

[A case of mediastinal parathyroid adenoma diagnosed by transtracheal needle aspiration]

Chest radiography of a 73-year-old man with upper abdominal pain showed hypercalcemia and an upper mediastinal mass. Functional mediastinal parathyroid adenoma was diagnosed, because of abnormally high levels of PTH in his serum and in fluid collected by transtracheal needle aspiration from the mediastinal mass. We resected the adenoma operatively. It a cystic tumor located behind the superior vena cava and the trachea. The inferior end of the tumor was as low as the aortic arch, and superiorly the tumor was attached to the inferior pole of the thyroid gland by a vascular pedicle. Histologically adenoma cells were predominant. This tumor was a mediastinal parathyroid adenoma by location, but because it was attached to the thyroid gland superiorly, it may have originated from the superior parathyroid gland and then descended because of its weight into the posterior superior mediastinum. Thus, it cannot be considered an ectopic parathyroid adenoma in origin. Mediastinal parathyroid adenoma is a rare disease, and these tumors are usually so small that correct localization of the adenoma is often difficult even by CT scan or scintigram. This is the first reported case of a mediastinal parathyroid adenoma that appeared as a mediastinal mass on a plain chest radiography and in which the level of PTH in the fluid collected from the mass by transtracheal needle aspiration was high.

Effects of alpha 2-plasmin inhibitor on plasminogen activation by staphylokinase/plasminogen complex

Using a stable cross-linked SAK/plg complex, the effects of alpha 2-plasmin inhibitor on plasminogen activation by SAK were investigated. alpha 2-Plasmin inhibitor inhibited dose-dependently plasminogen activation by the SAK/plg complex. When FCB-2 or EACA was added to the reaction mixture of SAK/plg complex and alpha 2-plasmin inhibitor, the inhibitory activity of alpha 2-plasmin inhibitor was abolished and the enzymatic activity of the complexes was restored. alpha 2-Plasmin inhibitor inhibited the activity of the SK/plg complex, but neither FCB-2 nor EACA restored the plasminogen activator activity in the mixture of SK/plg complex and alpha 2-plasmin inhibitor. Using 125I-labeled SAK/plg complex or SK/plg complex, the reaction of the complex with alpha 2-plasmin inhibitor was analyzed. The SAK/plg complex produced a new complex with alpha 2-plasmin inhibitor. The formation of a new high molecular weight complex with alpha 2-plasmin inhibitor was abolished by both EACA or FCB-2. With regard to the SK/plg complex, neither EACA nor FCB-2 suppressed the complex formation with alpha 2-plasmin inhibitor. These findings indicate that the SAK/plg complex binds to fibrin, and that this complex expresses plasminogen activator activity without being affected by alpha 2-plasmin inhibitor.

[A sporadic case of essential vitamin E deficiency manifested by sensory-dominant polyneuropathy and retinitis pigmentosa]

A 55-year-old woman with known retinitis pigmentosa for 25 years was progressively clumsy in gait and activities of daily living over the past 30 years. She was able to manage house work and social activities, but she developed swallowing disturbance associated with involuntary neck muscle spasm for 2 weeks, which brought her to our clinic on September 7, 1990. General physical examination was normal except for dry skin. Neurological examination was compatible with sensory-dominant polyneuropathy, showing distal dominant sensory impairment together with absent vibration sense and areflexia in lower limbs, but no gross muscular weakness. There were neck dystonia and bilateral poor visual acuity due to secondary optic atrophy of retinitis pigmentosa. The former responded to the combination of tiapride and trihexyphenidyl. She was admitted twice for further evaluation. Complete blood count and blood chemistry tests including lipids were all within normal limits, and so was cerebrospinal fluid. Pyruvate and lactate before and after exercise loading were also normal. Malignancy workup was negative. To our surprise, serum vitamin E level turned out very low (1.89 micrograms/ml), normal range being 4.7-20.3 micrograms/ml. Oral vitamin E administration test by 2g of alpha-tocopherol showed abnormal absorption curve followed fast clearance in serum. Stool was occasionally positive for fat corpuscles by Sudan III staining, but 99Tc-HSA leakage into the intestines was not detected.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects on bone metabolism of asthma treatment with beclomethasone dipropionate (BDP) inhalation and short term burst of oral steroids]

Inhaled steroids are currently the first-line treatment of chronic asthma. Because each metered dose of beclomethasone dipropionate (BDP) is small (50 micrograms), short term burst or continuous use of oral steroids are combined in moderately to severely asthmatic patients. The effect of these treatments on bone metabolism remains unclear. Bone mineral density (BMD), osteoclacin (OC), PTH, Ca, and ALP were assessed in 130 asthmatic patients. There were 3 groups: the first group [B+R] consisted of 17 patients taking BDP (1190 +/- 536 micrograms/day) and also taking oral steroids (8.0 +/- 3.8 mg/day, 8.11 +/- 5.52 years), the second group [B+S] had 35 patients taking BDP (885 +/- 320 +/- g/day) and short-term bursts of oral steroids (PSL 20-40 mg/day, 3-7 days/course, 7.51 +/- 4.54 courses/year) and the third group [B alone] consisted of patients who were taking BDP (480 +/- 260 micrograms/day) alone. BMD was measured by dual energy X-ray absorptiometry (DEXA). In the [B+R], [B+S], and [B alone] groups, the BMD of vertebra (L1-4) was 0.75, 0.86, and 0.90 g/cm2, respectively. The percentages of predicted values based on age and sex were 92.0, 102.7, and 106.9% respectively. BMD and percent decrease were significantly lower in the [B+R] group than in the [B+S] or [B alone] group. It is likely that this phenomenon is caused by long-term use of oral steroids rather than by BDP inhalation but there is no significant difference between the [B+S] and the [B alone] groups. Daily BDP dose did not correlate with BMD by multiple regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytotoxin-converting phages, phi CTX and PS21, are R pyocin-related phages

phi CTX is a temperate phage of Pseudomonas aeruginosa harbouring the ctx gene that encodes cytotoxin (CTX). We identified phi CTX as an R pyocin-related phage, by serological and molecular analysis, based on the findings that the infectivity of the phage was inhibited with the antisera directed R pyocins and R pyocin-related phages and that the phi CTX genome showed DNA homology to the genome of PS17 (a representative of the R pyocin-related phages) as well as to the pyocin R2 genes. Another new CTX-converting, R pyocin-related phage named PS21 was isolated from a CTX-producing strain of P. aeruginosa, suggesting the distribution of the ctx gene by certain members of R pyocin-related phage family.

[Phase II study of a continuous five-day intravenous infusion of cisplatin and etoposide with concurrent chest radiation therapy in limited stage small cell lung cancer]

The efficacy of continuous five-day intravenous infusion of cisplatin (CDDP) and etoposide with concurrent chest radiation therapy was evaluated in patients with limited stage small cell lung cancer. The first group of patients registered from February 1989 to September 1990 received three courses of chemotherapy (CDDP 20 mg/m2/day x 5 days, etoposide 40 mg/m2/day x 5 days) and concurrent chest radiation therapy on the third course with dose reduction of etoposide. The second group of patients registered after February 1991 received four courses of chemotherapy (CDDP 20 mg/m2/day x 5 days, etoposide 50 mg/m2/day x 5 days) and concurrent chest radiation therapy on the first and second courses with dose reduction of etoposide. The response rates were 91.7% and 93.3%, respectively. The median duration of survival was 32.0 months and 20.1 months, respectively. Major toxicity was leukocytopenia and 64% and 80% of patients encountered leukocytopenia of Grade 3 or 4. In conclusion, these regimens show remarkable efficacy with acceptable toxicity.