Reorganization of membrane cholesterol during membrane fusion in myogenesis in vitro: a study using the filipin-cholesterol complex.

Using filipin and freeze-fracture electron microscopy, we examined the distribution of membrane cholesterol during the fusion of myoblasts in vitro. The early stages of fusion were characterized by the depletion of cholesterol from the membrane apposition sites, at which the plasma membranes of two adjacent cells were in close contact. At first, filipin-cholesterol complexes were absent from the plasma membrane of one cell only and were distributed homogeneously on the membrane of the other cell.

Computed tomographic appearances of cardiac amyloidosis.

Computed tomography was used to identify the characteristic appearances of histologically confirmed cardiac amyloidosis in two patients. Mean myocardial density and 95% confidence limits in one of these patients (30.6 +/- 3.

Computed tomography of pararenal fluid collections in acute pancreatitis.

Acute pancreatitis is a serious condition with severe and, sometimes, fatal complications. In recent years, both computed tomography (CT) and ultrasound have improved the diagnosis of certain complications, particularly pseudocysts, extrapancreatic exudates and abscesses. A frequent site for extrapancreatic exudates is the pararenal space.

[Chemotherapy of biliary tract infections (XXIV). Biliary excretion and gallbladder tissue levels of mezlocillin].

Mezlocillin (MZPC), a new broad spectrum penicillin, was studied for its biliary excretion and levels in gallbladder tissues. The mean serum concentration immediately after intravenous administration of 2 g of MZPC in 6 cholecystectomized patients was found to be 535.5 +/- 43.

Recombination between short direct repeats in Streptomyces lavendulae plasmid DNA.

Streptomyces lavendulae S985 carried two plasmids, pSL1 and pSL2. pSL2 contained all of the pSL1 sequences plus a tandem duplication of 900 base pairs from a region of pSL1. Sequence analysis of the duplication junction suggested that the duplication occurred by recombination between short direct repeats of as little as 5 base pairs.

Non-ionic water soluble contrast medium 3-deoxy-3-iodo-D-glucose (DIG) for use in the CSF space. An experimental study with mongrel and beagle dogs.

A non-ionic water soluble contrast medium, 3-Deoxy-3-Iodo-D-Glucose (DIG), was experimentally evaluated for use in the cerebrospinal fluid (CSF) space, and compared with other contrast media. Two ml (180 mgI/ml) of DIG were injected either intraventricularly or intracisternally in 15 adult mongrel dogs (average weight: 6.4 kg), and X-ray photographic, CSF, EEG, and histological studies were then performed.

Transforming activity of human melanoma DNA.

Cellular DNA transfection to mouse NIH3T3 cells revealed transforming activity of human malignant melanoma DNA. The corresponding human sequence was cloned from the transformed mouse cells. By hybridization to viral oncogenes, the transforming gene in human melanoma was identified as a homologue of viral Ha-ras gene.

Nucleotide sequence of the regulatory region of malB operons in E. coli.

The nucleotide sequence of a cloned section of the Escherichia coli chromosome containing the promoter regions of the malB divergent operons was determined. The region of the proximal gene, malE of the malEFG operon, was identified on the basis of the known amino acid sequence of the precursor molecule of maltose-binding protein. The region of malK, the proximal gene of the malKlamB operon, was deduced from the observation that a cloned segment contains an amino-terminal portion of the malK gene.

Evidence for a vertical displacement of intramembranous particles on the plasma membrane of Tetrahymena cells by a local anesthetic.

We examined the effect of a local anesthetic, dibucaine, on the plasma membrane of Tetrahymena pyriformis strain NT-1 using freeze-fracture electron microscopy. Intramembranous particles (IMPs) were distributed homogeneously on the plasma membrane of untreated cells. But, when Tetrahymena cells had been treated with 1.

Effect of Intralipid-infusion on erythrocyte membrane in rabbits.

Through Intralipid infusion in rabbits, the phospholipids derived from Intralipid were incorporated into erythrocytes, although Intralipid is mainly composed of triglycerides. This is supported by the increase in oleic acid and the compensatory decrease in linoleic acid of the phospholipids in the erythrocyte membrane, corresponding to the content of linoleic acid in the phospholipids from Intralipid. The excess phospholipid rendered the membrane more fluid, probably by overwhelming the rigidifying effect of the increased cholesterol content.

Reorganization of membrane ergosterol during cell fission events of Candida albicans: a freeze-fracture study of distribution of filipin-ergosterol complexes.

The redistribution of ergosterol molecules which occurs during bud and germ tube formation (dimorphism) in Candida albicans was studied using filipin, a sterol-specific antibiotic, and examined by the freeze-fracture technique. When cells were fixed in a glutaraldehyde solution containing 50 micrograms/ml of filipin, filipin-ergosterol complexes, which were recognized as either pits on the exoplasmic fracture face or protuberances on the protoplasmic fracture face, were homogeneously distributed on the yeast plasma membranes. The plasma membrane of young budding yeast cells demonstrated few filipin-ergosterol complexes compared to the parent yeast plasma membrane.

Pyrimidine derivatives. 4. Synthesis and antihypertensive activity of 4-amino-2-(4-cinnamoylpiperazino)-6,7-dimethoxyquinazoline derivatives.

A series of 30 4-amino-2-(4-cinnamoylpiperazino)-6,7-dimethoxyquinazoline derivatives was prepared and tested for their ability to reduce blood pressure in conscious, spontaneously hypertensive rates (SHR). A number of these compounds, notably 4-amino-2-(4-cinnamoylpiperazino)-6,7-dimethoxyquinazolines 3a (R1 = H; R2 = Ph), 3j (R1 = H; R2 = 4-EtOPh), and 5a (R1 = H; R2 = 2-furyl), showed activity at oral doses of 0.3-10 mg/kg.

[Comparative double-blind study of cefotetan and cefmetazole in patients with purulent peritonitis].

A clinical study of daily administrations of CTT (2g) and CMZ (4g) was performed by randomized double blind techniques in order to compare the clinical efficacy, side effects and usefulness. The 150 cases studied were as follows; Purulent peritonitis due to perforated gastrointestinal tracts (122 cases), traumatic peritonitis (4 cases), biliary peritonitis (7 cases), postoperative peritonitis (7 cases), intraabdominal abscess (6 cases); 4 cases were excluded from the statistical evaluation because of protocol deviation. 1.

Electron microscopic study on the structures formed by mixtures containing synthetic glyceroglycolipids.

Structures of aqueous dispersions prepared from monoglycosyldiglycerides and from mixtures of monoglycosyldiglyceride and phosphatidylcholine were studied by freeze-fracture electron microscopy. Aqueous dispersions of glucosyl or galactosyl dipalmitylglycerol formed lamellar structures when quenched both from below and above the gel-liquid crystalline phase transition temperature. With mixtures of monoglycosyl dipalmitylglycerol and dipalmitoylphosphatidylcholine, tubular structures could be observed in the extended bilayer structures.

Changes of the auditory system after cerebellopontine angle manipulations.

The current tendency in acoustic neuroma surgery to attempt the preservation of hearing function and the problem of accidental hearing loss caused by microsurgical neurovascular decompression operations for hemifacial spasm or trigeminal neuralgia prompted us to study the exact surgical vulnerability of the auditory system. The surgical procedures for operation on the cerebellopontine angle of dogs were carried out according to the sequence of the posterior fossa transmeatal operation for acoustic neuroma. The operation was tentatively divided into three stages: (a) craniectomy and dural opening, (b) cerebellar retraction, and (c) identification of the cochlear nerve in the unroofed internal auditory canal (IAC).

Effect of phosphatidylinositol replacement by diacylglycerol on various physical properties of artificial membranes with respect to the role of phosphatidylinositol response.

In an attempt to gain insight into the physiological role of phosphatidylinositol turnover enhanced by extracellular stimuli, the physical properties of artificial membranes (egg yolk phosphatidylcholine/bovine brain phosphatidylserine) containing phosphatidylinositol or diacylglycerol were studied by ESR using spin probes and freeze-fracture electron microscopy. Diacylglycerol lost both the ability to form lipid bilayer structures and its susceptibility to calcium ions. Yeast phosphatidylinositol included in dipalmitoylphosphatidylcholine liposomes lowered the phase transition temperature of dipalmitoylphosphatidylcholine and expanded the temperature range of phase transition.

Effects of amphotericin B and its methyl ester on plasma membranes of Candida albicans and erythrocytes as examined by freeze-fracture electron microscopy.

Freeze-fracture electron microscopy of the plasma membranes of Candida albicans yeast cells and red blood cells treated with amphotericin methyl ester and amphotericin B showed that amphotericin B (50 micrograms ml-1) caused extreme aggregation of intramembranous particles on the protoplasmic fracture face of the C. albicans membrane, and a marked reduction of the density of intramembranous particles. On the other hand, the rearrangement of intramembranous particles induced by amphotericin methyl ester (50 micrograms ml-1) produced elevations of the particle-free membrane domains toward the outside of the cells, so that the particles were aggregated in linear furrows surrounding these elevations on the protoplasmic fracture face, and the corresponding ridges on the exoplasmic fracture face.