MgCl2 supported titanium catalyst prepared by mechanical pulverization

Summary MgCl₂ supported titanium catalysts were prepared by mechanical pulverization or MgCl₂ with titanium compounds using two types of machines, rotatory mill and vibratory mill. Both methods gave substantially the same results, although vibratory mill much saved the milling time. The nature of the fixed titanium compounds was not homogeneous, and the titanium compounds fixed at an earlier stage of milling, which could be located at exposed active edge positions of MgCl₂ particles, showed higher activity in ethylene polymerization. On the other hand, those fixed at the later stage showed lower activity and caused reaggregation of the particles. Furthermore, chlorine-free titanate compounds, Ti(OBu)₄ and Ti(OEt)₄, also could be fixed on MgCl₂ which showed high activity in ethylene polymerization.     

Natural history of diabetes mellitus with special reference to age of onset and vascular complications

Age and sex distribution of diabetics, seasonal incidence of diabetes, grade of hyperglycemia, frequency of vascular complications and daily living conditions were studied of 2771 diabetic patients experienced at five clinics. The cases consisted of 1587 male and 1184 female diabetics. The distribution of age of diabetes onset revealed that males predominate among diabetics but females predominate among child diabetics, and that the precentage of child was extremely low. This pattern was emphasized as characteristic of Japanese diabetic population. Distribution of fasting blood sugar at the diagnosis of diabetes was compared among the age groups of diabetes-onset and the results showed that percentage of the value exceeding 300 mg/100 ml was highest in the under 10 year-onset cases and decreased with age. The frequency of diabetic retinopathy and of ischemic ECG changes was analysed from the view point of age of diabetes onset and also the duration of the disease. The frequency of the retinopathy at the diabetes-onset was zero in the under 10 year-onset cases, 4.2% in the 10s-onset cases and increased with age. The longer the duration of the disease the higher the frequency of the retinopathy was. This increase along with the duration was most remarkable in the 10s- and 20s-onset cases and less remarkable in the 30s-onset cases. The retinopathy was significantly more frequent in female diabetics. Daily of the patients were studied by a questionnaire and the analysis of 1022 cases with diabetes of more than three years revealed that cases of patients working uneventfully and/or feeling fit were most frequent among the 30s- or 40s-onset cases and that cases of bed-disability were frequent among the cases whose diabetes was found in their twenties or younger. This study showed that the prognosis of the patients is quite different according to whether their diabetes occurred before of after 30 years of age.     

Increased expression of nucleoside diphosphate kinases/nm23 in human diploid fibroblasts transformed by SV40 large T antigen or 60Co irradiation

YACHIYODA SZ-5000 is a new model of lithotriptor made in Japan, of which the energy source is microexplosion. Compared with the old type of SZ-1, the water bag is substituted for a hot water bath and ultrasonography as well as fluoroscopy can be used for stone localization. Moreover, this new model is extremely small. The first clinical trial of 32 candidates with urinary tract calculi (34 stones) was performed at our hospital between September 1991 and June 1992. They were 10 women and 22 men between 25 and 71 with a mean of 47.3 years. All patients received no anesthesia. The stone location was: R2 for 16 stones, R3 for 5, U1 for 9, U2 for 1, and U3 for 3. The mean size was 14.1 mm. A mean number of 364, 326 and 324 shock waves were given for the R2, 3, U1, and U2, 3 stones, respectively. The second or third sessions were performed on 7 patients. Obvious symptoms and signs observed during the treatment were; local pain in 9 patients, nausea in 3, hypotension and bradycardia in 6, and hypertension in 3. Posttreatment fever up was found in two patients. In 34 stones, the efficiency evaluated 3 months later was 85.0% as determined by kidney-ureter-bladder X-ray and intravenous pyeography. In conclusion, YACHIYODA SZ-5000 is useful and safe in the management of patients with urinary tract stones.     

Pancreatic diabetes in Japan

Islets of Langerhans surrounded by a semipermeable membrane to prevent an immune response by the host immunosystem is a potential way of treating type I diabetes mellitus. In this study, poly(vinyl alcohol) (PVA) tubular membranes with added polyethylene glycol to create pores in the skin layer were prepared to improve their diffusion property. In a static incubation study, islets cultured in the PVA tubular membranes still demonstrated their function of secreting insulin after 30 days. When the tubular PVA bioartificial pancreas was perifused in a small chamber with RPMI-1640 medium containing glucose at concentrations of 5.6-16.6 mmol/L, insulin release began to increase without delay. Therefore, such a membrane is an alternative potential material for a bioartificial pancreas. In addition, a mathematical mass transfer model of insulin release was developed and compared with the perifusion data. It was shown that satisfactory kinetics could be achieved with a PVA membrane. However, the model showed that the insulin output of islets cultured in the PVA tubular membrane must be increased to improve the performance significantly. These findings suggest that a bioartificial pancreas using a PVA membrane is a promising material, but the technique for seeding islets in the chamber requires further modification.     

Analysis of cell damage and proliferation in Helicobacter pylori-infected human gastric mucosa from patients with gastric adenocarcinoma

Helicobacter pylori (HP) infection, a cause of multifocal atrophic gastritis, is considered an important factor related to the evolution of the human gastric mucosa from normal to intestinal-type adenocarcinoma. We examined cell proliferation and both double and single strand DNA damage in situ in 35 patients undergoing gastrectomy for adenocarcinoma with HP-infected gastric mucosa by immunolocalization of Ki-67, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, and in situ nick translation. We also studied the distribution of intraepithelial neutrophils by elastase immunolocalization. HP infection was confirmed in all cases by serum anti-HP antibodies, ureas testing, and histopathological examination. HP-infected gastric mucosa was classified according to the degree of inflammation and intestinal metaplasia. Ki-67, terminal deoxynucleotidyl transferase-mediated labeling, in situ nick translation, and intraepithelial neutrophil indices all increased with the progression of gastritis and were highest in glands with incomplete intestinal metaplasia. All indices were lowest in gastric glands with complete intestinal metaplasia. Significant positive correlations were observed among these markers. Increased proliferative activity in HP-associated chronic gastritis in response to cell damage or injury was clearly demonstrated, suggesting that both HP-associated toxins and intraepithelial neutrophils are important in HP-related gastric epithelial injury. Increased cell turnover associated with incomplete intestinal metaplasia may result in DNA instability and subsequent development of intestinal-type gastric adenocarcinoma in HP-infected mucosa.     

Increased expression of costimulatory molecules on peripheral blood monocytes in patients with Crohn's disease

BACKGROUND: Activation of T lymphocytes and monocytes/macrophages has been implicated in the pathogenesis of Crohn's disease (CD). Costimulatory molecules play important roles in optimal T-cell activation. METHODS: With flow cytometric analysis we have investigated the expression of the costimulatory molecules B7-1 (CD80), B7-2 (CD86), and CD18 and the intercellular adhesion molecule-1 (ICAM-1) on peripheral blood monocytes and the expression of the activation markers HLA-DR and IL-2R (CD25) on peripheral blood T lymphocytes from 31 CD patients, 17 ulcerative colitis (UC) patients, and 10 healthy controls. RESULTS: In CD patients the percentage of activated T cells (CD3+ HLA-DR+ and CD3+ IL-2R+) was significantly increased compared with those of controls and UC patients (P < 0.05). Most monocytes from all three groups expressed B7-2, CD18, and ICAM-1 molecules (all > 79%), but only a few positive cells expressed B7-1 molecules (< 5%). No significant differences were detected in the percentage positivity of all costimulatory molecules tested among CD, UC, and controls. The mean fluorescence intensity (MFI) of B7-1 in all three groups was very weak and not significantly different. However, in CD patients there was a significantly increased MFI of B7-2, CD18, and ICAM-1 molecules compared with UC and controls (P < 0.05). On the other hand, both the percentage positivity and MFI of HLA-DR molecules on monocytes of UC patients were significantly lower than those of CD patients and controls (P < 0.05). CONCLUSIONS: Expression of the costimulatory molecules B7-2, CD18, and ICAM-1 on peripheral blood monocytes of CD patients is increased. In CD patients activation of peripheral T lymphocytes may correlate with increased expression of these costimulatory molecules on peripheral blood monocytes.     

Lipopolysaccharide induces manganese superoxide dismutase in the rat pancreas: its role in caerulein pancreatitis

Intraperitoneal injection of lipopolysaccharide (LPS) at a dose of 50 micrograms/kg increased the activity and the mRNA level of manganese superoxide dismutase (Mn-SOD) but did not change those of copper/zinc-SOD (Cu/Zn-SOD) in the rat pancreas. Both the formation of pancreatic edema and the elevation of serum amylase during caerulein pancreatitis were significantly relieved in the rats pretreated with LPS (50 micrograms/kg) compared with the rats without the pretreatment. These results support the view that superoxides play a key role in the pathogenesis of caerulein pancreatitis, and that Mn-SOD in the pancreas may work as a defense against the development of this disease.     

Magnetic torque of κ-(BEDT-TTF)2Cu(NCS)2 single crystals

The magnetic torque ofκ-(BEDT-TFF)₂Cu(NCS)₂ was measured as a function of field directionθ with respect to thea ^*-axis under constant magnetic fields,H, up to 8 kOe in the temperature range from 1.3 to 8 K. A sharp cusp, C₁, in the irreversible region was found atθ _c1 near theH∥bc-plane between 1.3 and 7 K. In addition, extra cusps, C₂ and C₃, were observed atθ _c2 andθ _c3, respectively, between 2.5 and 6 K. At each temperature, the perpendicular component ofH giving each cusp is kept constant as $H\cos \theta _{cn} = const \equiv H_{cp_n } (n = 1,2,3),$ i.e., cusps C₁, C₂, and C₃ are ruled by the characteristic field perpendicular to thebc-planeH _cp1,H _cp2, andH _cp3, respectively. These behaviors are almost the same as those we found in the oxide superconductor Bi₂Sr₂CaCu₂O₈. These results suggest that the cusps are intrinsic for irreversible vortex states of these layered superconductors.     

Effect of magnetic iron impurity on the superconducting properties of an amorphous Nb50Zr35Si15 alloy

The effect of magnetic iron impurity on the superconducting properties of amorphous Nb₅₀Zr_35−x Si₁₅Fe _x (x⩽4 at %) alloys was examined. Doping with an iron impurity resulted in a linear depression ofT _c andH _c2(T) and a decrease in andρ _n after reaching a maximum value at 0.5 to 1.0 at % iron. The observed decrease was about 35% forT _c, 85% forH _c2 at 2.0 K, 16% for and 21% forρ _n. Although the decrease in occurs through the decrease inρ _n as expected from the GLAG theory, the depression inT _c caused by magnetic impurity could not be explained in terms of the GLAG theory which is applicable to Nb-Zr-Si amorphous alloys without magnetic impurity, but was interpreted as arising from the pair-breaking effect in the superconducting nature due to magnetic scattering. However, the pair-breaking effect was found to be smaller by about one-tenth for the present amorphous superconductors than for crystalline superconductors, indicating the high stability of the superconductivity of the Nb-Zr-Si-Fe alloys against the magnetic scattering arising from the magnetic impurity. The reduced magnetic field at which the reduced fluxoid pinning force exhibits a maximum value increased with iron concentration, indicative of an enhancement of fluxoid pinning force. The enhancement in fluxoid pinning force was interpreted as arising from the increase in compositional, electronic and/or magnetic fluctuations by the dope of iron impurity.     

Macroscopic and pathohistological investigation of endarterial plaque after intraoperative balloon dilatation of the carotid artery during carotid endarterectomy

Twelve patients associated with stenosis of the extracranial carotid artery underwent intraluminal balloon dilatation during carotid endarterectomy (CEA). There were 11 men and 1 woman, and age ranged from 56 to 73 years old. The rate of stenosis, shown by angiography, in each patient was from 60 to 85% in width. After securing carotid blood flow by a T-shaped shunt tube, a balloon catheter was inserted from the exposed common carotid artery into the internal carotid artery. The balloon was inflated three or four times with 2.5-3.5 atm. for 30-40 seconds. Immediately after balloon dilatation, endoscopic investigation was performed (Wolf; hard type endoscope, 2.7 mm diameter). Then CEA was performed using the usual procedure. The removed endarterial plaque was investigated pathohistologically. In macroscopic and endoscopic findings, there were 6 patients with mural thrombosis, 4 patients with laceration of the intima, and one patient with outflow of atheroma from the intima. Only 3 patients had increase in lumen after balloon dilatation. In pathohistological appearance, all patients had a moderate degree of fibrosis, calcification, and atheroma in the cross section of the plaque. Ten patients had intramural hemorrhage. Three typical patients were revealed by the use of angiographical, ultrasonographical, endoscopic, and pathohistological presentation. Case 10 showed laceration of the intima by balloon dilatation, and had moderate increase in lumen size macroscopically and endoscopically. There were moderate cases of fibrosis, calcification, atheroma, and intramural hemorrhage. Dilatation of the lumen seemed to be accomplished by a decrease in thickness of the atheroma and intramural hemorrhage. Case 8 demonstrated an increase in lumen size, but also laceration of the intima and outflow of atheroma from the arterial wall. There were much atheroma and large intramural hemorrhage in the intima, which might become a source of enbolism. Case 7 revealed no laceration of the intima and no increase in lumen size. Preoperative ultrasonography showed hyperechoic finding and postoperative pathohistological findings showed severe fibrosis and calcification, which were thought to have interrupted balloon dilatation. There have been small numbers of reports about pathohistological presentation after percutaneous transluminal angioplasty (PTA), because it is very difficult to take a specimen after PTA. In this report we were able to present the necessity of preoperative investigations by angiography, ultrasonography, and 3D-CT.