Mutual link among the approaches to clipping of basilar aneurysms

The pterional approach for basilar aneurysm clipping, has become the most common approach among surgeons, since it was advocated by Yasargil in 1982. However, other approaches aiming at an adequate but less invasive surgery to meet conditions of peripheral blood vessels (including aneurysmal size, direction and perforating arteries and arteriosclerosis) and the direction of clip insertion have also been developed. The approaches will be recommended to be expanded according to situations of the actual intra-operative findings in the future. The mutual link among the approaches to clipping of basilar aneurysms was investigated.

[Participation of apoptosis in renal amyloidosis]

Renal amyloidosis shows symptoms of renal dysfunction due to the deposition of amyloid protein in the kidney. Recently, it was reported that apoptosis plays an important role in the pathogenesis of type-2 diabetes mellitus and Alzheimer's disease of which amyloid deposition is seen in the tissue. We investigated whether or not apoptosis and related factors are observed in renal amyloidosis. In situ nick end labeling (TUNEL) was performed in seven autopsied renal tissues with primary and secondary amyloidosis and 10 autopsied renal tissues without renal disease as the control. The number of TUNEL-positive cells was significantly increased in both the glomeruli and tubulus of the kidney with amyloidosis than in the control. Electron microscopic analysis was performed on one biopsied renal tissue with amyloidosis and six biopsied renal tissues with minor abnormalities as the control. Typical apoptotic cells were observed only in the former. Bax product, an inducer of apoptosis, and Bcl-2 protein, an inhibitor of apoptosis, were examined immunohistochemically in the seven autopsied renal tissues with amyloidosis and 10 autopsied control tissues. Bax was overexpressed in the tubulus and glomeruli of subjects with renal amyloidosis, compared to the normal controls. However, Bcl-2 protein was not detected in the glomeruli in any of the subjects examined. These results indicate that apoptotic cells are increased in number in renal amyloidosis and Bax overexpression may play an important role in this increase.

Insulin enhances macrophage scavenger receptor-mediated endocytic uptake of advanced glycation end products

Hyperglycemia accelerates the formation and accumulation of advanced glycation end products (AGE) in plasma and tissue, which may cause diabetic vascular complications. We recently reported that scavenger receptors expressed by liver endothelial cells (LECs) dominantly mediate the endocytic uptake of AGE proteins from plasma, suggesting its potential role as an eliminating system for AGE proteins in vivo (Smedsrod, B., Melkko, J., Araki, N., Sano, H., and Horiuchi, S. (1997) Biochem. J. 322, 567-573). In the present study we examined the effects of insulin on macrophage scavenger receptor (MSR)-mediated endocytic uptake of AGE proteins. LECs expressing MSR showed an insulin-sensitive increase of endocytic uptake of AGE-bovine serum albumin (AGE-BSA). Next, RAW 264.7 cells expressing a high amount of MSR were overexpressed with human insulin receptor (HIR). Insulin caused a 3.7-fold increase in endocytic uptake of 125I-AGE-BSA by these cells. The effect of insulin was inhibited by wortmannin, a phosphatidylinositol-3-OH kinase (PI3 kinase) inhibitor. To examine at a molecular level the relationship between insulin signal and MSR function, Chinese hamster ovary (CHO) cells expressing a negligible level of MSR were cotransfected with both MSR and HIR. Insulin caused a 1.7-fold increase in the endocytic degradation of 125I-AGE-BSA by these cells, the effect of which was also inhibited by wortmannin and LY294002, another PI3 kinase inhibitor. Transfection of CHO cells overexpressing MSR with two HIR mutants, a kinase-deficient mutant, and another lacking the binding site for insulin receptor substrates (IRS) resulted in disappearance of the stimulatory effect of insulin on endocytic uptake of AGE proteins. The present results indicate that insulin may accelerate MSR-mediated endocytic uptake of AGE proteins through an IRS/PI3 kinase pathway.

Conversion of Amadori product of Maillard reaction to Nepsilon-(carboxymethyl)lysine in alkaline condition

Nepsilon-(carboxymethyl)lysine (CML) is known to be formed by oxidative cleavage of Amadori products between C-2 and C-3 of the carbohydrate chain. We report here that CML formation from Amadori compounds is highly accelerated under alkaline conditions. Incubation of glycated human serum albumin (HSA) in 0.1 N NaOH led to the formation of CML whereas glycated HSA reduced by NaCNBH3 or non-glycated HSA did not generate CML. Nalpha-t-butyloxycarbonyl-Nepsilon-fructoselysine (Boc-FL), a model compound of Amadori product, was converted to CML under alkaline conditions. CML level of human sera (n=224) preincubated with 0.1 N NaOH correlated well with glycated albumin value (r=0.912) and hemoglobin A1c (r=0.797).

Multiple regression analysis of airway responsiveness in adult asthmatic patients

The aim of this study was to determine which background variables exert the most influence on airway responsiveness in adult asthmatic patients. The relationships between airway response and background variables were investigated by multiple linear and logistic regression analysis in 97 asthmatic patients. Airway responsiveness was measured by the oscillation technique during methacholine inhalation challenge. The regression analyses revealed that modified Aas score "one of asthma severity score", was the major factor contributing to airway hyperreactivity. We conclude that the number of attacks during a previous year is the most important background factor related to airway hyperresponsiveness on a clinical basis.

Effect of operator variability on dentin adhesion: students vs. dentists

The purpose of this study was to evaluate the operator variability of two dentin bonding systems. Fourteen undergraduate students and ten dentists of different levels of clinical experience were selected. Tensile bond strengths between resin composite and bovine dentin using dentin adhesive systems (Clearfil Liner Bond II: LB II; Scotchbond Multi-Purpose: MP) bonding systems showed a large scatter among students and dentists. The dentists group demonstrated no statistically significant differences for mean bond strengths between LB II and MP. The student group recorded a statistically greater bond strength using LB II. The mean coefficient of variation of the dentists group showed no statistically significant difference between LB II and MP, however that of the students group was lower with LB II. When using MP, the dentist group demonstrated a lower coefficient of variation than that of the student group. In order to obtain optimal bonding performance, or when beginning the use of a new system, the operator should be aware of the technique sensitivity of some adhesive systems and sensitivity to operator variability.

Analysis of chimeric proteins identifies the regions in the carbohydrate recognition domains of rat lung collectins that are essential for interactions with phospholipids, glycolipids, and alveolar type II cells

Pulmonary surfactant proteins A (SP-A) and D (SP-D) are collectins in the C-type lectin superfamily. SP-A binds to dipalmitoylphosphatidylcholine and galactosylceramide, and it regulates the uptake and secretion of surfactant lipids by alveolar type II cells. In contrast, SP-D binds to phosphatidylinositol (PI) and glucosylceramide (GlcCer). We investigated the functional region in the carbohydrate recognition domain of rat SP-A and SP-D that is involved in binding lipids and interacting with alveolar type II cells by using chimeric proteins. Chimeras ad3, ad4, and ad5 were constructed with SP-A/SP-D splice junctions at Gly194/Glu321, Gln173/Thr300, and Met134/Cys261, respectively. All three chimeras lost SP-A-specific functions. Chimeras ad3, ad4, and ad5 bound to PI with increasing activity. In contrast, chimeras ad3 and ad4 did not bind to GlcCer, whereas ad5 avidly bound this lipid. From these results, we conclude that 1) the SP-A region of Glu195-Phe228 is required for lipid and type II cell interactions, 2) the SP-D region of Cys261-Phe355 is required for optimal lipid interactions, and 3) the structural requirement for the binding of SP-D to PI is different from that for GlcCer.

[Idiopathic insomnia]

Idiopathic insomnia (Childhood-onset insomnia) which belongs to Intrinsic Sleep Disorders in ICSD, has some dysfunction in sleep-wake center in brain. Sleep-wake center consists of two parts, one is sleep center which is present in the anterior parts of hypothalamus, and the other is wake center which is present in the ascending reticular activating system including posterior parts of hypothalamus. Idiopathic insomnia patients are said to have hyperactivity in wake center or hypoactivity in sleep center. And these patients have sleep disturbances such as inability to fall asleep, frequent awakenings and early morning wakefulness. Most patients have sleep disturbances from their childhood and after the onset of sleep disturbances, these disturbances show no improvement during all their life. Concerning about the drug treatment, probably benzodiazepin or barbiturate are effective. Because of long-term use of drugs, drug dependence and tolerance are often observed in patients. So it is necessary to take special care when choosing type or dosage level of drugs.

[A case of systemic lupus erythematosus complicated with marked intestinal edema and paralytic ileus]

A 43-years-old female was admitted to our hospital because of facial erythema and photosensitivity in 1983 and was diagnosed as systemic lupus erythematosus (SLE). She was treated with betamethazone 2.5 mg/day as an outpatient. Abdominal pain and diarrhea were developed in September, 1995. So she was admitted to our hospital and diagnosed as having paralytic ileus. Ultrasonography showed marked intestinal edema. Forbidden oral intake and given antibiotics, she was satisfactorily improved in a few days, but the symptoms got worse soon. We forbid oral intake again. We performed a pulse therapy with 1 g of methylprednisolone and increased a dose of betamethasone 2.5 to 4.0 mg/day, but the symptoms were not improved. Since October 6th, serum creatinine level (s-CRE) increased to 8.1 mg/dl at October, 20th. We suspected the worsening of SLE nephropathy or drug-induced nephropathy, so we stopped a medication of pravastatin and used 50 mg/day of azathioprine. Moreover, we did a pulse therapy of methylprednisolone and a plasmapheresis. By these treatments, s-CRE level returned to normal range and paralytic ileus was completely improved. The cause of hypercreatininemia was suspected to be rhabdomyolysis due to pravastatin. The main cause of paralytic ileus with intestinal edema was suspected to be vascular disturbance of superior mesenteric arteries. We consider that pulse therapy and plasmapheresis are useful for a patient of SLE with marked intestinal edema and paralytic ileus.

A transcrista galli, translamina terminalis approach for highly placed basilar bifurcation aneurysms

Surgery for highly placed basilar bifurcation aneurysms is one of the most difficult operations in neurosurgery. Specific surgical techniques have been developed including the temporopolar, zygomatic, transzygomatic subtemporal, transclinoid trans-seller transcavernous, and trans third ventricular approaches. The authors present some technical advances which have been developed for the transcristagalli translamina terminalis approach for the treatment of this aneurysm.

The effect of supplemental propionate on insulin responsiveness to glucose and tissue responsiveness to insulin in relation to feeding in sheep

Two glucose clamp techniques were performed for 6 h starting 2 h before the initiation of feeding to investigate the effect of dietary propionate supplementation on insulin responsiveness to glucose and tissue responsiveness to insulin in relation to feeding in rams. The rams were fed alfalfa hay without (Cont diet) and with 10 mmol.kg BW-1.d-1 of calcium propionate (Prop diet) for 4 weeks in randomized order. With the hyperglycemic clamp, the ratio of plasma insulin increment to glucose infusion rate did not differ between the diets, but for the Prop diet the ratio was less during the pre-feeding period. With the hyperinsulinemic euglycemic clamp, the glucose infusion rate was lower (P < 0.05) for the Prop diet than the Cont diet, and increased (P < 0.05) after feeding. In rams supplemented propionate tissue responsiveness to insulin was reduced. Propionate supplementation may either impair glucose utilization in response to insulin infusion or enhance glucose production from propionate.

Increased mRNA expression of cardiac renin-angiotensin system and collagen synthesis in spontaneously hypertensive rats

Hypertensive cardiac hypertrophy is associated with the accumulation of collagen in the myocardial interstitium. Previous studies have demonstrated that this myocardial fibrosis accounts for impaired myocardial stiffness and ventricular dysfunction. Although cardiac fibroblasts are responsible for the synthesis of fibrillar collagen, the factors that regulate collagen synthesis in cardiac fibroblasts are not fully understood. We investigated the effects of angiotensin II on cardiac collagen synthesis in cardiac fibroblasts. Cardiac fibroblasts of 10 week old spontaneously hypertensive rats and age-matched Wistar-Kyoto rats were prepared and maintained in culture medium supplemented with 10% fetal calf serum. The expression of mRNA of the renin-angiotensin system (renin, angiotensinogen, angiotensin converting enzyme) was determined by using a ribonuclease protection assay. Basal collagen synthesis in cardiac fibroblasts from spontaneously hypertensive rats was 1.6 fold greater than that in the cell of Wistar-Kyoto rats. Angiotensin II stimulated collagen synthesis in cardiac fibroblasts in a dose-dependent manner. The responsiveness of collagen production to angiotensin II was significantly enhanced in cardiac fibroblasts from spontaneously hypertensive rats (100 nM angiotensin II resulted in 185 +/- 18% increase above basal levels, 185 +/- 18 versus 128 +/- 19% in Wistar-Kyoto rats p < 0.01). This effect was receptor-specific, because it was blocked by the competitive inhibitor saralasin and MK 954. These results indicate that collagen production was enhanced in cardiac fibroblasts from spontaneously hypertensive rats, that angiotensin II had a stimulatory effect on collagen synthesis in cardiac fibroblasts, and that cardiac fibroblasts from spontaneously hypertensive rats were hyper-responsive to stimulation by angiotensin II. Level of angiotensin and renin mRNA expressed in ventricles, and angiotensinogen mRNA expressed in fibroblasts from SHR were higher than those from WKY. These findings suggest that the cardiac renin-angiotensin system may play an important role in collagen accumulation in hypertensive cardiac hypertrophy.

Clinical study of 16 fully grown cerebral aneurysms

The mechanismus of recurrence and enlargement of 16 cerebral aneurysms have been analyzed: 2 dissecting aneurysms, 6 fully grown aneurysms after neck clipping, 1 case after treatment with dome clip, 3 ruptured aneurysms that developed at the same sites and 4 cases that developed at other sites. From our investigation we concluded it was fundamentally important that the factor of the elastic lamina interna must attach in whole around the neck with precise neck clipping or adequate tight embolization involving positioning of the remaining elastica lamina interna in coil embolization.

Granulocyte-macrophage colony-stimulating factor and IL-5 activate mitogen-activated protein kinase through Jak2 kinase and phosphatidylinositol 3-kinase in human eosinophils

Mitogen-activated protein (MAP) kinases are activated by the sequential activation of Ras, Raf, and MEK (MAP kinase kinase) and regulate a wide variety of cell functions. To determine the kinase cascade for granulocyte-macrophage colony-stimulating factor (GM-CSF)- and IL-5-induced MAP kinase activation in eosinophils, we studied the effect of inhibitors of Jak2 kinase, tyrosine kinases, phosphatidylinositol 3-kinase, and protein kinase C on GM-CSF- and IL-5-induced MAP kinase activation in human eosinophils. GM-CSF and IL-5 activated 40, 42, and 44 kilodalton MAP kinase isoforms in eosinophils. This was indicated by the electrophoretic mobility shift of the three isoforms of MAP kinase in immunoblotting with anti-MAP kinase antibody and also by in-gel MAP kinase assay. MAP kinase activation was time- and dose-dependent, becoming maximal 3 to 15 minutes after stimulation. A Jak2 kinase inhibitor AG-490, a tyrosine kinase inhibitor genistein, and a phosphatidylinositol 3-kinase inhibitor wortmannin inhibited GM-CSF- and IL-5-induced MAP kinase activation in eosinophils, whereas a protein kinase C inhibitor staurosporine had a weak inhibitory effect. Furthermore, AG-490 and genistein prevented GM-CSF-induced tyrosine phosphorylation of Jak2 kinase in eosinophils. Taken together, these results indicate that GM-CSF and IL-5 activate MAP kinases through the signaling pathway of Jak2 kinase-tyrosine phosphorylated beta chain-phosphatidylinositol 3-kinase-Ras in eosinophils.

Classification and treatment of vertebral dissecting aneurysm

BACKGROUND

For many years, dissecting aneurysms of the intracranial vertebral artery were believed to be quite rare. In recent years, because vascular disorders have been studied more thoroughly by three dimensional-computed tomography (3D-CT), angiographically and pathologically, these aneurysms are being reported with more frequency.

METHODS

Among the 45 patients diagnosed to have aneurysms arising from the vertebral artery or its branches over a 20-year period, 16 had dissecting aneurysms. The authors present their therapeutic strategy for these patients. Surgery was performed in the 16 patients, the most common technique being clip-occlusion or trapping of the parent artery wherever feasible, in an attempt to optimize cerebral blood flow. The dissecting aneurysms of the vertebral artery were classified into two groups for the purpose of determining a therapeutic approach, namely unilateral and circumferential groups. In the unilateral group, the dissection seemed to involve only on one side of the vessel according to the conventional cerebral angiogram. These patients underwent surgical reconstruction of the vertebral artery by direct clipping. In the circumferential group, the dissection was all around the artery. Proximal clipping or trapping was performed in this group.

RESULTS

In six out of eight patients with unilateral dissecting aneurysms, vascular reconstruction was possible by direct clipping. Of these six patients, the surgical outcome was considered excellent in four, fair in one, and one patient died of cardiac failure after 12 days as his preoperative morbid condition remained the same after surgery. Two other patients with unilateral dissecting aneurysms were treated with trapping technique and the surgical outcome was excellent in one patient and good in the other patient. Both patients resumed a normal social life. In five out of eight patients with circumferential dissecting aneurysms, trapping or proximal clipping was performed and the surgical outcome was excellent in two patients, good in one and fair in one patient. One patient with preoperative brain stem infarction died of aspiration pneumonitis after 8 months. Two patients who were noted to have an increase in the size of aneurysm during follow-up angiography underwent a craniotomy with clipping and wrapping of the aneurysm. There was a favorable surgical outcome in both patients. The remaining three patients had Grade IV subarachnoid hemorrhage (SAH) prior to surgery and at autopsy a disturbed vascular wall was detected.

CONCLUSION

The authors' experience suggests that when surgically feasible, direct clipping is an effective alternative approach in the treatment of dissecting aneurysms of the vertebral artery in which blood flow in the parent artery is to be preserved.

Extrahepatic portosystemic venous shunt without portal hypertension

A 72-year-old woman was admitted for recurrent episodes of encephalopathy. Laboratory data showed mild liver dysfunction and hyperammonemia, while she had neither anemia nor splenomegaly. The dilated inferior mesenteric vein (IMV) was opacified retrogradely from the superior mesenteric vein by superior mesenteric arteriography, and IMV was found to connect with the inferior vena cava (IVC) through a torturous shunt. No obstruction of the extrahepatic portal vein or hepatic vein was observed by arteriography. Histological evaluation of the liver biopsy indicated remarkable fatty change without cirrhosis. Finally, we diagnosed this case as extrahepatic portosystemic venous shunt without portal hypertension.

IDC Embolization of Aneurysms

SUMMARY

Embolization using IDC was carried out for 33 aneurysm cases in the last 3 years. The indication for the embolization was that the direct surgery was considered to be difficult, because of 1) technically impossible to do clipping, 2) aneurysm of the posterior fossa, 3) reject of patients. Regarding the location of aneurysm, 27 cases were seen in the anterior circulation, and 6 cases in the posterior circulation. Count of 33 cases, 11 cases were ruptured and 22 cases were non-ruptured. The procedure of embolization of aneurysms are generalized as compared to direct surgery, but there remain some technical problems. 33 cases in our series had no significant complication, except for one which had ruptured again. We emphasize that the weak point of IDC which was so hard, had no variations, especially if it happens to migrate during locking procedure. These complications can be prevented, if we use GDC(5,6,7) instead of IDC.

Isolation of a rat histidase cDNA sequence and expression in Escherichia coli--evidence of extrahepatic/epidermal distribution

Histidase (histidine ammonia-lyase) is a cytosolic enzyme responsible for catalyzing the non-oxidative deamination of histidine to urocanic acid. Full-length cDNAs encoding rat histidase have been isolated from a lambdaZAP liver cDNA library using a partial cDNA fragment obtained by PCR. Whereas the initial description of the rat histidase 3' untranslated sequence contained a rare polyadenylation signal sequence, the data presented encompass a more distant 28-bp region, possessing a nucleotide stretch (AATATAAA), identical to that in the mouse histidase cDNA. Dideoxynucleotide chain-termination sequencing of two clones obtained by in vivo excision yielded an additional 376 bp and 105 bp of 5' and 3' untranslated sequences, respectively. A selected rat histidase cDNA clone was introduced into the pET-16b prokaryotic vector and expressed in BL21(DE3)pLysS Escherichia coli. After purification by nickel-chelation chromatography, recombinant histidine-tagged protein was employed to raise anti-(rat histidase) immunoglobulin in a Japanese white rabbit. The polyclonal rabbit antibody recognized and formed immune complexes with rat and recombinant human histidase proteins. Immunoblots of crude rat organ extracts detected a spectrum of histidase expression extending beyond that observed in liver and skin. Among other histidase-positive cells were those of the renal cortex tubular epithelium, fundic mucosal glands of stomach, gastric intramuscular (Auerbach's) plexus, and adrenal cortex. Immunohistochemical studies of histidase in rat liver produced discrete staining of hepatocytes in association with portal triads (Rappaport zone I). Furthermore, in contrast with previous reports of activity confined to epidermal stratum corneum, our findings demonstrate immunoreactive protein within and limited to the adjacent stratum granulosum.

Hydroxyakalone, a novel xanthine oxidase inhibitor produced by a marine bacterium, Agrobacterium aurantiacum

A new xanthine oxidase inhibitor named hydroxyakalone was isolated from the culture broth of a marine bacterium Agrobacterium aurantiacum N-81106. Structure of hydroxyakalone was determined to be 4-amino-1H-pyrazolo[3,4-d]pyrimidine-3-one-6-ol by the spectral studies of hydroxyakalone and its permethyl derivative. The concentration to induce 50% inhibition (IC50) was 4.6 microM against xanthine oxidase.