Increase in ceramide level after application of various sizes of sphingomyelin liposomes to a cultured human skin model.

Sphingomyelin-based liposomes (SPM-L) that were sized (or not) by extrusion through a filter with pores of 100, 200, or 400 nm were applied to a three-dimensional cultured human skin model in order to evaluate which size of SPM-L was most effective at increasing its ceramide level. The diameters of the SPM-L in PBS were 102.7, 181.0, 224.0, and 380.1 nm. The diameters of the liposomes in the culture medium were 117.5, 199.2, 242.1, and 749.8 nm. The diameter of the small liposomes (<200 nm in diameter) did not change much, at least for 7 days. SPM-L in saline or culture medium were applied to the basal layer side or stratum corneum side of the cultured skin model, and ceramide II, III, V, and VI were then extracted from it. The extracted ceramide molecules were separated by HPTLC, and the concentration of each type of ceramide was quantified using a densitometer. When the small SPM-L (110 or 190 nm in diameter) were applied to the basal layer side, the levels of ceramide III and V were increased. When they were applied to the stratum corneum side, the levels of ceramide II, III, V, and VI were significantly increased compared to those of the PBS group, especially after the application of the small SPM-L (110 nm in diameter). Thus, the application of small SPM-L was useful for increasing the ceramide II, III, V, and VI levels of a cultured human skin model.

Effect of famotidine on recurrent bleeding after successful endoscopic treatment of bleeding peptic ulcer.

AIM: We investigated the effect of acid suppression therapy on recurrent bleeding after successful endoscopic treatment of bleeding peptic ulcer. METHODS: A total of 400 patients with bleeding peptic ulcer received either intravenous infusion of famotidine (40 mg/day) (n = 207, 163 males, 44 females, mean age 61.5 years) or drip infusion of omeprazole (40 mg/day; n = 193, 134 males, 59 females, mean age 59.8 years) after successful endoscopic treatment. The fasting duration, hospital stay, volume of transfused blood, incidence of rebleeding and mortality were compared between the two groups. RESULTS: The incidence of rebleeding did not differ significantly between the famotidine group (9%) and the omeprazole group (8%). The mean hospital stay was significantly shorter in the omeprazole group (18.4 days) than in the famotidine group (21.5 days, P = 0.009). However, there was no statistically significant difference in fasting duration, volume of transfused blood or mortality. CONCLUSION: Our findings indicate that intravenous infusion of famotidine after successful endoscopic treatment is equivalent to drip infusion of omeprazole for prevention of recurrent bleeding.

Effect of additives on insulin absorption from intratracheally administered dry powders in rats.

The lungs are useful for administration of macromolecules, which are poorly absorbed from the intestine. In the present study, we prepared several dry powder formulations of insulin using a spray drying technique to examine the effect of additives on insulin absorption. The bioavailability of insulin was estimated from the change in the plasma glucose level. The bioavailability of insulin from dry powder with no additive exceeded that obtained from pH 7.4 solution. The absolute bioavailability of insulin administered as a solution with 1.4 mg/dose of bacitracin or 1.0 mg/dose of Span 85 was almost 100%. The bioavailability of dry powder with 0.42 mg/dose of bacitracin was 20% that of the solution with 1.4 mg/dose of bacitracin. The insulin dry powder with 0.21 mg/dose of Span 85 showed a bioavailability less than that for the insulin solution with 0.1 mg/dose of Span 85. Bacitracin and Span 85 were not as effective in dry powder as in solution in the present study. While citric acid was more effective in dry powder that in solution to increase the hypoglycemic effect. The pH 5.0 and pH 3.0 solutions containing 0.19 mg of citric acid in 0.1 ml showed absolute bioavailabilities of 43% and 57%, respectively, while the bioavailabilities for dry powders containing 0.025 and 0.036 mg/dose citric acid were 42% and 53%, respectively. In addition, the hypoglycemic effect of dry powders continued for a longer period and remained at 240 min with the dry powders, while it disappeared at 180 min with the solutions. When the insulin dry powder containing 0.036 mg/dose of citric acid was administered, the lactate dehydrogenase activity, a sensitive indicator of acute toxicity to lung cells, in bronchoalveolar lavage was as low as that for saline administration, suggesting citric acid is a safe additive. Thus, citric acid appears to be a safe and potent absorption enhancer for insulin in dry powder.

Impairment in biochemical level of arterial dilative capability of a cyclic nucleotides-dependent pathway by induced vasospasm in the canine basilar artery.

The authors investigated the changes and the potential of cyclic nucleotide-dependent signal transduction, which induces smooth muscle relaxation, in the basilar artery with severe vasospasm in dogs with double experimental subarachnoid hemorrhage (SAH) to explore at which biochemical level the arterial dilative capability was impaired. The amount of cyclic adenosine and guanosine monophosphates (cAMP and cGMP) decreased significantly in the basilar artery after SAH. The activities of adenylate and guanylate cyclases also were decreased significantly in the smooth muscle cells of the basilar artery 4 days after SAH. In addition to the failure of the pathways to produce cyclic nucleotides, the activities of cAMP- and cGMP-dependent protein kinases, which are representative actual enzymes that amplify the signal for vascular dilation, also significantly decreased together with the almost total loss of activation by cyclic nucleotides in the same basilar artery after SAH. It was revealed that the system for smooth muscle relaxation was impaired severely in the cerebral arteries with severe vasospasm after SAH, on the biochemical basis of significantly less vasodilative capability and in several of the steps to produce the cyclic nucleotides of intracellular signal transduction.

Protein synthesis and immunoreactivities of contraction-related proteins in smooth muscle cells of canine basilar artery after experimental subarachnoid hemorrhage.

We examined time-dependent changes in protein synthesis and in the immunoreactivities of representative contraction-related structural proteins in smooth muscle cells of canine basilar arteries after experimental subarachnoid hemorrhage (SAH). Protein synthesis was assessed by the percentage of polyribosome-forming ribosomes to total ribosomes (aggregation rate), a morphological index of the activity of protein synthesis. The aggregation rates in prostaglandin F2 alpha-(PGF 2 alpha) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced contracted basilar arteries were 70.0 +/- 7.0% and 71.4 +/- 8.7%, respectively, quite similar to the value in normal basilar artery (73.0 +/- 8.0%). In the single-SAH group with little delayed histological changes in the basilar arteries, the aggregation rate was significantly decreased to 30.5 +/- 6.4% by 24 h after the SAH, and recovered to 52.3 +/- 9.0% and 70.2 +/- 7.6% at 7 and 14 days postSAH, respectively, when the vasospasm was moderately and completely ameliorated. In contrast, in the double-SAH group in which the basilar arteries developed delayed smooth muscle cell death and long-lasting arterial contraction, a significant decrease in the aggregation rate (25.0 +/- 5.0% on day 4) persisted for 14 days. The in vitro incorporation of [3H]-leucine in the basilar arterial cells was also significantly suppressed 4 and 7 days after the initial SAH (1.2 +/- 0.4 and 1.4 +/- 0.3 x 10(3) dpm/mg protein) in the double-SAH group, as opposed to no significant decrease in the basilar artery at 7 days postSAH in the single-SAH group (1.9 +/- 0.6 x 10(3) dpm/mg protein). The immunoreactivity of alpha-smooth muscle actin, a contractile protein, demonstrated by immunohistochemistry and immunoblots, was not altered for up to 14 days even in the double-SAH group, but that of calponin and of h-caldesmon, contraction-inhibiting proteins, was markedly reduced 4-14 days after the initial SAH. Persistent impairment of protein synthesis and relative reduction of immunoreactivities of the contraction-inhibiting proteins were observed in arteries with severe vasospasm and loss of smooth muscle cells, as noted in the double-SAH subjects. These abnormalities may cooperate to cause cerebral arterial narrowing accompanied by degeneration of smooth muscle cells after SAH.

Primary spinal chondrosarcoma localized in the cervical spinal canal and intervertebral foramen--case report.

A 48-year-old male presented with a very rare case of spinal chondrosarcoma localized in the cervical spinal canal and intervertebral foramen, but without marked destruction of the vertebral column. Spinal chondrosarcoma is characterized by radiological evidence of destruction of the surrounding bone structure and mottled calcification. Magnetic resonance imaging was useful in the diagnosis and determination of the extent of this spinal chondrosarcoma. However, preoperative differential diagnosis of the tumor was not possible based on neuroimaging evidence.

Possible mechanism to induce protein kinase C-dependent arterial smooth muscle contraction after subarachnoid haemorrhage.

A possible mechanism for the induction of protein kinase C (PKC)-dependent vascular contraction independent to the increase of intracellular Ca++ was investigated in the pathogenesis of cerebral vasospasm in the double subarachnoid haemorrhage (SAH) model. The level of 1,2-diacylglycerol (DAG), which is an intrinsic PKC activator, significantly increased from days 4 to 7 in the basilar artery after the initial SAH, and the continuous administration of 1,2-bis(nicotinamido)-propane (AVS), a novel free radical scavenger, not only lowered the concentration of lipid peroxides in the CSF but also successfully suppressed the basilar arterial wall in the same model. It was suggested that lipid peroxides generated in the subarachnoid clot affect the DAG content of the cerebral artery. Analysis of hydroxy-eicosatetraenoic acids (HETEs) with high performance liquid chromatography (HPLC) revealed the production of relatively large amount of 12-HETE in the subarachnoid clot. To examine the potential effect of exogenous 12-HETE on the DAG content of the cerebral artery, the basilar artery was incubated with 12-HETE in vitro. 12-HETE induced a concentration-dependent slow increase in DAG content in the arterial wall after 6 hours of incubation. Under conditions in which DAG formation was facilitated by the Ca(++)-ionophore, DAG accumulation in the basilar artery was enhanced in the presence of 12-HETE. It was suggested that 12-HETE generated in the subarachnoid clot, induced DAG accumulation in the arterial wall by inhibition of DAG metabolism, resulting in the induction of prolonged PKC-dependent smooth muscle contraction in the pathogenesis of cerebral vasospasm.

Usefulness of nucleolar organizer region staining in gastric myogenic tumors: correlation with ploidy by DNA flow cytometry.

A silver-staining technique to identify nucleolar organizer region-associated proteins (Ag-NOR) was applied to 55 gastric myogenic tumors. The mean numbers of Ag-NOR in the nucleus were: leiomyoma (30 cases), 2.0 +/- 0.6 (mean +/- SD); low-grade leiomyosarcoma (11 cases), 3.0 +/- 0.7; and high-grade leiomyosarcoma (14 cases), 3.9 +/- 0.7. The Ag-NOR counts were compared with DNA ploidy as determined by flow cytometry in 46 tumors. The Ag-NOR counts were significantly different in the aneuploid leiomyosarcomas (4.1 +/- 0.6: mean +/- SD) and diploid leiomyosarcomas (2.9 +/- 0.6: mean +/- SD). Thus, this parameter may serve as an objective histological discriminant for malignancy.

p53 point mutations in primary human gastric carcinomas.

p53 point mutations in primary gastric carcinomas were analyzed by performing cDNA deoxynucleotide sequencing of the gene. Out of 16, 9 (56.3%) primary gastric carcinoma cases, including early cancer, showed one or more p53 point mutations in their open-reading frame, and 4 out of 9 cases had a p53 point mutation within highly conserved domains. The characteristics of the p53 mutation spectrum observed in primary tumors were (a) frequent mutation at an A:T pair (50%, 7 out of 14 mutations), (b) high transversion incidence (29%, 4 out of 14 mutations), (c) no transition at CpG, and (d) no G:C to T:A transversion. Our results suggest that p53 mutation is a common event in gastric carcinoma occurring from the early stage of progression with its specific mutation spectrum.