Effects of sphingomyelin and cholesterol on lipoprotein lipase-mediated lipolysis in lipid emulsions

Lipoprotein lipase (LPL) hydrolyzes triacylglycerol (TG) of TG-rich lipoproteins. We investigated the effects of sphingomyelin (SM) and cholesterol (Chol) on the lipolysis of lipid emulsions by LPL using human apolipoprotein C-II (apoC-II) or plasma as an activator. Kinetic studies of the lipolysis rates clearly demonstrated that the primary effect of the activator on the LPL reaction was not to increase the affinity of LPL for the emulsion surface, but to enhance LPL catalytic activity. Incorporation of SM into the emulsion surface caused increases in Km(app) and decreases in Vmax(app), indicating that SM inhibited lipolysis by decreasing both affinity for substrates and catalytic activity of LPL. SM was also found to affect possible factors related to the lipolysis rates; that is, SM increased TG solubility in surface layers and decreased apoC-II binding to the emulsion surface. Interestingly, Chol did not affect the lipolysis rates even though it decreased TG solubility and apoC-II binding. These results indicated that neither TG solubility nor amount of apoC-II binding were determinate factors in LPL-mediated lipolysis under physiological conditions. Our results suggest that the content of SM in the lipoprotein surface plays an important role by controlling lipoprotein lipase-mediated lipolysis, and that cholesterol enrichment in the lipoprotein surface has no influence on lipolysis, but may affect other metabolic processes such as uptake by the liver through the selectivity of apolipoprotein binding.

Cholesterol derivative of poly(ethylene glycol) inhibits clathrin-independent, but not clathrin-dependent endocytosis

The effect of poly(ethylene glycol) cholesteryl ethers (PEG(n)-Chols) with two different numbers of units (n = 50 and 200) in the hydrophilic PEG moiety on cellular endocytic activity was studied on HT-1080 cells. The amphipathic molecules were soluble in aqueous solution. When fluorescein derivatives of PEG-Chols (one fluorescein at the distal end of PEG) were incubated with the cells in culture, the cellular fluorescence was localized at the plasma membrane level and in intracellular vesicles. Fluorescence quantification indicated that for the same external concentration, twice more FPEG(50)-Chol than FPEG(200)-Chol was associated with the cells under the same conditions. Regardless of the length of PEG moiety, PEG-Chols' interaction with cells reduced the endocytic internalization of a fluid phase marker, horseradish peroxidase (HRP) depending on the cell-associated amount. In contrast, internalization of 125I-labeled epidermal growth factor (EGF) through receptor-mediated endocytosis did not change upon incubation with PEG(50)-Chol. The effect of PEG(200)-Chol was also small, since EGF internalization showed a reduction of 10-20%, while at the same concentration as much as 80% of HRP uptake was inhibited. PEG(50)-Chol did not influence the internalization of a larger ligand, 125I-transferrin (Tfn). However, in the presence of PEG(200)-Chol, the uptake of 125I-Tfn decreased remarkably, and yet, PEG(200)-Chol has no influence on the binding and internalization of a monoclonal antibody directed toward the ectodomain of the Tfn-receptor. These results suggested that incorporation of PEG-Chols in the outer monolayer of the plasma membrane specifically inhibited clathrin-independent, but not clathrin-dependent endocytosis.

An estimation of craniofacial growth in the untreated Class III female with anterior crossbite

The literature has little to say regarding the normal growth and development of untreated individuals with Class III malocclusion or anterior crossbite. In part, this paucity of information is because of the relatively low prevalence of these characteristics in European-American populations and the need, recognized by the lay public and health professionals, for treatment of these conditions. Given the absence of true longitudinal data, this study attempts to estimate the growth of the untreated individual with Class III malocclusion and anterior crossbite by evaluating large samples of untreated subjects at distinct developmental stages. Initially the morphologic characteristics of 2074 Japanese female patients who had anterior crossbite were evaluated cephalometrically before treatment. On the basis of the cephalometric analysis, all subjects who did not have a Class III molar relationship were excluded from further analysis, leaving a sample of 1376. The subjects then were classified into seven groups (120-256 subjects per group) according to Hellman's stages of dental development. Descriptive statistics for 28 measurements were calculated. The results of this study imply that the maxilla in Japanese females maintains a retruded relationship to the cranial base and does not become less retrusive with time. In contrast, the mandible is protrusive even in the late deciduous dentition and becomes more protrusive with time, making the discrepancy between the upper and lower jaws progressively more severe. Dental compensations in both arches become increasingly evident as development progresses, and the underlying skeletal and dentoalveolar imbalances also are reflected in the soft tissue profile.

Synthesis of Tn and sialyl Tn antigen-lipid A analog conjugates for synthetic vaccines

Conjugates of Tn and sialyl Tn antigen with N-teradecanoyl L-seryl-beta-alanine-containing D-glucosamine derivatives structurally related to lipid A as an immunoadjuvant were synthesized for the development of totally synthetic vaccines against cancers or HIV.

Uprighting the mandibular molars stimulates mandibular growth during treatment of class II malocclusion

We hypothesized that uprighting of the mandibular molars creates a counter-clockwise rotation of the mandible and stimulates mandibular forward growth during the treatment of a Class II malocclusion. This investigation used 33 longitudinal lateral cephalometric radiographs of Class II, Division 1 female patients. All cases were treated with non-extraction. Treatment was started in early adolescence with .018 slot edgewise Alexander appliances. High-pull head-gear and Class II elastics were used. Seventeen cases that showed more than 5 degrees of uprighting of the mandibular first molars were selected as the uprighted group. Cases that showed less than 5 degrees of uprighting of the mandibular first molars were selected as the non-uprighted group. There was a significant correlation coefficient between the uprighted degree of the mandibular first molars and the degree of clockwise rotation of the mandibular plane to FH.

Membrane permeabilization mechanisms of a cyclic antimicrobial peptide, tachyplesin I, and its linear analog

Tachyplesin I (T-SS), an antimicrobial peptide from Tachypleus tridentatus, has a cyclic antiparallel beta-sheet structure maintained by two disulfide bridges. The peptide effectively permeabilizes both bacterial and artificial lipid membranes. T-Acm, a linear analog peptide with the four SH groups protected by acetamidomethyl groups, exhibits a much weaker membrane-permeabilizing activity in spite of a greater disruption of the lipid organization [Matsuzaki, K., Nakayama, M., Fukui, M., Otaka, A., Funakoshi, S., Fujii, N., Bessho, K., & Miyajima, K. (1993) Biochemistry 32, 11704-11710]. To clarify the efficient permeabilization mechanism of T-SS, we studied the interactions of both peptides with liposomes and planar lipid bilayers. The cyclic peptide capable of spanning the bilayer (ca. 3 nm length) was found to form an anion-selective pore and translocate across the bilayer coupled with the pore formation. A cis-negative transmembrane potential facilitated the pore formation compared with the cis-positive potential. In contrast, the linear peptide failed to translocate. Instead, it impaired the membrane barrier by disrupting the lipid organization with morphological changes in the vesicles.

High-efficiency entrapment of superoxide dismutase into cationic liposomes containing synthetic aminoglycolipid

A monofatty acid ester of glucosamine (PGlcN) was synthesized to provide liposomal membranes with a positive charge, and the trapping efficiency of negatively charged substances (superoxide dismutases, SODs) into cationic liposomes containing PGlcN or stearylamine (SA) prepared by various methods was compared to find the most efficient trapping methods. We demonstrated that cationic liposomes, which were prepared in a buffer of low ionic strength containing sorbitol by a simple hydration method, could entrap a large amount of negatively charged SODs which retained their activity, as compared with cationic liposomes prepared in a buffer of high ionic strength. We also showed a reverse-phase evaporation method entrapped a large amount of SODs. However, SODs were inactivated during the preparation; therefore, this method was not suitable to entrap the enzyme. Freeze-thaw method induced the formation of cationic liposomes which were smaller than extruded liposomes and could entrap the SODs in a buffer of low ionic strength. Dehydration-rehydration method with a buffer of low ionic strength also entrapped a large amount of SODs, indicating that the integrity of liposomes was lost in the lipid bilayer after freeze-drying and the SODs were entrapped in the reconstruction of liposomes during rehydration. These findings showed that the hydration method based on electrostatic attraction with a buffer of low ionic strength was simple and the most effective for entrapping SODs without loss of their activity.

Pore formation and translocation of melittin

Melittin, a bee venom, is a basic amphiphilic peptide, which mainly acts on the lipid matrix of membranes, lysing various cells. To elucidate the molecular mechanism, we investigated its interactions with phospholipid vesicles. The peptide formed a pore with a short lifetime in the membrane, as revealed by the release of an anionic fluorescent dye, calcein, from the liposomes. Our new double-labeling method clarified that the pore size increased with the peptide-to-lipid ratio. Upon the disintegration of the pore, a fraction of the peptides translocated across the bilayer. The pore formation was coupled with the translocation, which was proved by three fluorescence experiments recently developed by our laboratory. A novel model for the melittin pore formation was discussed in comparison with other pore-forming peptides.

Interactions of an antimicrobial peptide, magainin 2, with outer and inner membranes of Gram-negative bacteria

Magainin peptides, isolated from Xenopus skin, have broad spectra of antimicrobial activity and low toxicities to normal eukaryotic cells, thus being good candidates for therapeutic agents. The mechanism of action is considered to be the permeabilization of bacterial membranes. A number of studies using lipid vesicles have elucidated its molecular detail. However, their interactions with bacteria are not yet well understood. In this paper, we synthesized several magainin analogs with different charges (0 to +6) and hydrophobicities, and systematically studied their interactions with the outer and inner membranes of three species of Gram-negative bacteria (Escherichia coli, Acinetobacter calcoaceticus, Proteus vulgaris). The treatment of the E. coli cells with native magainin 2 (+4) immediately induced the efflux of the intracellular K+ ions and the cell death. A number of blebs were formed on the bacterial surface and the outer membrane became leaky. An increase in the peptide's positive charge enhanced the outer membrane permeabilization and the bactericidal activity. The cationic peptides also effectively permeabilized the inner membranes rich in acidic phospholipids, indicating the importance of electrostatic interactions. Substitution of Trp for Phe simultaneously increased the bactericidal activity and the hemolytic activity. A strategy to develop potent antimicrobial peptides was discussed on the basis of these results.

PF1092A, B and C, new nonsteroidal progesterone receptor ligands produced by Penicillium oblatum. II. Physico-chemical properties and structure elucidation

The structures of PF1092A (1), B (2) and C (3), new nonsteroidal progesterone receptor ligands produced by Penicillium oblatum, were elucidated by spectroscopic analyses. These compounds possess an eremophilane-type sesquiterpene carbon skeleton and differ only in that 1 and 2 are different monoacetates of 3. The absolute configurations of 1-3 were determined by single crystal X-ray diffraction analysis of the 4-bromobenzoyl ester of PF1092A and by measuring the optical rotations of the acetylation products of these compounds.

Giant hepatic angiomyolipoma associated with disseminated intravascular coagulation

We report a case of giant hepatic angiomyolipoma in a 68-year-old woman who had an increase in the fibrinolytic activity concomitant with disseminated intravascular coagulation (DIC). The presence of the tumor was confirmed by ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen and the selective arteriography of the liver via the superior mesenteric artery. Following treatment with heparin and gabexate mesilate, abnormal hemostatic values were corrected. Furthermore, the surgical removal of the huge hepatic angiomyolipoma completely normalized the alternations of the clotting system. These findings suggest that giant hepatic angiomyolipoma was profoundly associated with DIC.

Modulation of magainin 2-lipid bilayer interactions by peptide charge

Magainin 2, an antimicrobial peptide from Xenopus skin, assumes an amphiphilic helix when bound to acidic phospholipids, forming a pore composed of a dynamic, peptide-lipid supramolecular complex [Matsuzaki et al. (1996) Biochemistry 35, 11361-11368]. Upon the disintegration of the pore, a fraction of the peptide molecules stochastically translocates across the bilayer (Matsuzaki, et al., 1995). In order to investigate the effects of peptide charge on the magainin 2-lipid bilayer interactions, we synthesized four magainin 2 analogs with different charges (0-6+). MG0: K10E, K11E, F12W-magainin 2. MG2+: K10E, F12W-magainin 2. MG4+: F12W-magainin 2. MG6+: F12W, E19Q-magainin 2 amide. An increase in charge resulted in a stronger binding of the peptide to the negatively charged membranes, suggesting that electrostatic attractions play a crucial role in the binding process. The helical stability in a trifluoroethanol/buffer mixture was decreased with increasing positive charge because of electrostatic repulsions between the closely spaced positive side chains, whereas the helicity in the lipid bilayer was much higher and appeared to be independent of the peptide charge. However, enhanced repulsions between the highly positively charged helices destabilized the pore. Therefore, the efficiency of the most basic peptide (MG6+) to translocate across the bilayer was the greatest by virtue of the short life span of its pore and the very tight membrane binding. The charge distribution of wild-type magainin 2 was found to be so designed as to exhibit the maximal lytic activity by simultaneously achieving a strong binding and a moderate pore stability.

Effect of cholesterol on apolipoprotein A-I binding to lipid bilayers and emulsions

The effects of cholesterol (Chol) on the interaction of apolipoprotein A-I (apoA-I) with phospholipid bilayer vesicles and lipid emulsions were investigated. ApoA-I bound to phosphatidylcholine (PC) vesicles with higher affinity and lower capacity compared to triglyceride-PC emulsions. An increase in surface Chol in triglyceride-PC emulsions decreased the binding capacity without changing the binding affinity. In contrast, addition of Chol to PC vesicles caused a marked increase in capacity and decrease in affinity for apoA-I binding. ApoA-I caused a large release of entrapped aqueous dye, calcein, from PC vesicles, whereas this apoA-I-induced leakage was relatively small in the vesicles containing Chol. The incorporation of phosphatidylethanolamine into the vesicles also exerted effects similar to those of Chol on apoA-I binding and calcein leakage. The shifts of fluorescence emission maximum of dansyl lysine, probing the surface region of membranes, indicated that Chol as well as phosphatidylethanolamine increased the headgroup space of the vesicles. The binding maximum of apoA-I was closely correlated with the emission maximum of dansyl lysine, not with the fluorescence anisotropy of I-[4-(trimethylamino)phenyl]phenylhexatriene, suggesting that the binding capacity of apoA-I to the bilayer surface was modulated by the headgroup space rather than the acyl chain fluidity. These results show that Chol affects the bilayer surface so as to allow more apoA-I to bind to bilayers and may suggest the possibility of the interaction of apoA-I with Chol-enriched membrane domains.

[Lung volume reduction surgery for pulmonary emphysema--report of two cases]

Lung volume reduction surgery (LVR) was practiced in 2 male patients with pulmonary emphysema to improve pulmonary function. On admission, they complained of exertional dyspnea (Grade III of the Hugh-Jones dyspnea scale). Computed tomographic scan (band display) revealed emphysematous changes throughout both lung fields, especially in bilateral upper lobes. Nuclear lung perfusion scintigraphy showed markedly diminished blood flow in both upper lobes. The bilateral upper lobes of each patient were excised through median sternotomy using the linear stapling device. The staple lines were buttressed with bioabsorbable polyglycolic acid fabric. At 1 month after LVR, the forced expiratory volume in 1 second improved, respectively, from 0.51 L to 1.27 L (Case 1) and from 0.68 L to 0.85 L (case 2). In conclusion, LVR was useful to improve pulmonary function of the patients with pulmonary emphysema.

[Surgical treatment for patients with atypical mycobacteriosis]

We have been conducting surgical therapy for patients with atypical pulmonary mycobacteriosis (AM) since 1965 and have reported on the outcome of this approach to treatment. We have found that chemotherapy is not adequately efficacious against type III Mycobacterium avium complex (MAC), which suggests that surgical intervention may be the optimum approach for MAC. Among MAC patients who were treated surgically at our hospital in the period between 1966 and 1994, 74 cases on whom postoperative follow-up observation was possible served as the subjects of the present investigation. We report here on the outcome of treatment and related problems in these patients. Thirty-nine patients gave positive results for bacterial discharge on smear tests and all were positive on culture. Operation was performed on the right lung in 46 patients and on the left lung in 16. Pneumonectomy was conducted in 10 patients and lobectomy in 20. Other operative modes used included segmental resection in 9, pyothorax in 7, and thoracoplasty in 5 patients. Postoperative bacterial excretion was observed in 15 patients and was persistent bacterial discharge were advanced cases with lesions in another lobe, cases with a past history of tuberculosis, cases of cavitation with lesions on the contralateral side or cases with massive bacterial discharge prior to surgery. Postoperative death occurred in 5 patients: the cause of death was lung cancer in 1 case, serum hepatitis in 1 case, and respiratory failure evidenced by enlarged shadows in 3 cases. These findings pointed to a marked significance of surgical therapy for MAC patients. However, recurrent bacterial discharge has been observed occasionally in some patients even 5 years after surgery. This suggests the need for careful ongoing assessment of the efficacy of surgical therapy and long-term postoperative follow-up.

Sustained release of flufenamic acid from a drug-triacetyl-beta-cyclodextrin complex

Triacetyl-beta-cyclodextrin (TA-beta-CyD), a hydrophobic cyclodextrin derivative that is insoluble in water, was used to form a complex with flufenamic acid (FA). Complexes of FA with TA-beta-CyD (FA-TA-beta-CyD) at various molar ratios (1:1, 1:2, 1:3) were prepared by a kneading method, using ethanol as a solvent. FA-TA-beta-CyD complex formation was demonstrated by differential scanning calorimetry and powder X-ray diffractometry. The release rate of FA from the FA-TA-beta-CyD complexes was measured in both the Japanese Pharmacopoeia XII 1st fluid pH 1.2 and isotonic phosphate buffer pH 6.8. The release rate of FA from the FA-TA-beta-CyD complexes in the isotonic phosphate buffer pH 6.8 was significantly retarded compared to the release rate of FA from the FA-glucose mixture. After 1 h, 100% of the drug was released from the FA-glucose mixture and 10-25% was released from the complexes. When either the powder of the FA-glucose mixture or the FA-TA-beta-CyD mixture was administered directly into the intraduodenal lumen in rats, the plasma concentration of FA reached a maximum level within 40 min after administration. On the other hand, when the FA-TA-beta-CyD complexes were administered into the intraduodenal lumen, the plasma concentration of FA did not show a sharp peak, but remained at a plateau level (10-18 microg/ml) for 6-8 h. An increased mean residence time of FA following FA-TA-beta-CyD complexes administration was observed; however, the AUC(0-10) for the FA-TA-beta-CyD complexes showed no significant difference from that for the FA-TA-beta-CyD mixture. These results indicate that TA-beta-CyD may serve as a hydrophobic carrier in sustained-release preparations of FA. The drug-TA-beta-CyD complexes may therefore be useful in oral administration to achieve prolonged action and reduced side effects.

Lipid A and related compounds. XXX. Synthesis of biologically active N,N'-diacyl chitobiose derivatives structurally related to lipid A

Two new glycolipids, which mimic lipid A disaccharide, were synthesized from N,N'-diacylchitobiose via a key intermediate (2). They showed mitogenicity and nitric oxide (NO) productivity.

Craniofacial structure of Japanese and European-American adults with normal occlusions and well-balanced faces

The purpose of this study is to compare two groups of adults from different races who were selected on the basis of having normal ("ideal") occlusions and well-balanced faces. The lateral cephalometric radiographs of 54 Japanese adults (26 men and 28 women) were compared with a sample of 125 adults (44 men and 81 women) of European-American ancestry. The samples were chosen by orthodontists of the same racial background as the sample selected. Each lateral cephalogram was traced and digitized, and differences between cephalometric measurements between groups were analyzed with completely randomized t tests. In comparison to the European-American sample, the Japanese sample, in general, was smaller in anteroposterior facial dimensions and proportionately larger in vertical facial dimensions. The facial axis angle was more vertical in Japanese subjects, indicating a more downward direction of facial development. On average, the subjects in the Japanese sample were more protrusive dentally, with a more acute nasolabial angle and a greater tendency toward bilabial protrusion. These differences, evident even in groups with so-called "well-balanced faces", indicate that fundamental variation exists in the craniofacial structure of Japanese and European-Americans. The results of this study support the premise that a single standard of facial esthetics is not appropriate for application to diverse racial and ethnic groups.

An antimicrobial peptide, magainin 2, induced rapid flip-flop of phospholipids coupled with pore formation and peptide translocation

The effect of an antimicrobial peptide, magainin 2, on the flip-flop rates of phospholipids was investigated by use of fluorescent lipids, i.e., anionic N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)dipalmitoyl-L-alpha- phosphatidylethanolamine (NBD-PE), 1-oleoyl-2-[12-((7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)- dodecanoyl]-L-alpha-phosphatidic acid (C12-NBD-PA), 1-oleoyl-2-[12- ((7-nitrobenz-2-oxa-1,3-diazol-4-yl)- amino)dodecanoyl]-L-alpha-phosphatidyl-L-serine (C12-NBD-PS), and zwitterionic 1-palmitoyl-2-[6-((7- nitrobenz-2-oxa-1,3-diazol-4-yl)amino)caproyl]-L-alpha-phosphatidy lcholine (C6-NBD-PC). Their intrinsic flip-flop half-lives at 30 degrees C in the absence of the peptide were 1.1 h, ca. 7 h, ca. 8 days, and > 2 days, respectively. The peptide accelerated the flip-flop half-lives of the fluorescent lipids to an order of minutes. Furthermore, the flip-flop was coupled with the membrane permeabilization and the peptide translocation [Matsuzaki, K., Murase, O., Fujii, N., & Miyajima, K. (1995) Biochemistry 34, 6521-6526], suggesting pore-mediated flip-flop. The flip-flop rate was independent of the initial labeling conditions (outer leaflet label or inner leaflet label). From these results, a model was proposed, in which the lipids translocate across the membrane by lateral diffusion along the wall of the pores composed of the peptides and the lipids. A simple theoretical calculation could explain the coupling of the flip-flop with the permeabilization.

Orthodontic treatment of an open bite patient with oral-facial-digital syndrome

A case of oral-facial-digital syndrome was treated orthodontically. Characteristics of this case were mandibular protrusion with open bite. Occlusal stability after correction of this malocclusion was achieved with the uprighting of the posterior teeth, surgical reduction of the enlarged tonsils and highly attached tongue frenum, and oral functional training.

Load on the low back of teachers in nursery schools

In order to evaluate the load on the low back of teachers in nursery schools, basic activity, working posture, child-lifting, and desk-lifting were analyzed for eight nursery teachers using video recording. The trunk inclination angle (TIA) was also measured continuously during full workshifts for 20 nursery teachers using an inclination monitor. The nursery teachers in the 0-1 (year) age class more often adopted low working postures, "sitting on the floor" and "kneeling," while teachers in the 4-5 age class more frequently adopted high working postures, "standing" and "sitting on a chair." The mean of TIA among all subjects was 20 degrees. The time spent at a TIA of more than 20 degrees represented 43% of the workshift. The mean and time distribution of TIA did not differ between the age classes. The frequency of trunk-lifting from severe bending forward (TIA > 45 degrees) was 86 times/hour on average. The frequency of trunk-lifting was highest in the 0-1 age class. The number of times of child-lifting was 46 in the 0-1 age class, while it was 1 in the 4-5 age class.