The organic aerosols of Titan

A dark reddish organic solid, called tholin, is synthesized from simulated Titanian atmospheres by irradiation with high energy electrons in a plasma discharge. The visible reflection spectrum of this tholin is found to be similar to that of high altitude aerosols responsible for the albedo and reddish color of Titan. The real (n) and imaginary (k) parts of the complex refractive index of thin films of Titan tholin prepared by continuous D.C. discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mb is determined from x-ray to microwave frequencies. Values of n (approximately equal to 1.65) and k (approximately equal to 0.004 to 0.08) in the visible are consistent with deductions made by ground-based and spaceborne observations of Titan. Many infrared absorption features are present in k (lambda), including the 4.6 micrometers nitrile band. Molecular analysis of the volatile component of this tholin was performed by sequential and non-sequential pyrolytic gas chromatography/mass spectrometry. More than one hundred organic compounds are released; tentative identifications include saturated and unsaturated aliphatic hydrocarbons, substituted polycyclic aromatics, nitriles, amines, pyrroles, pyrazines, pyridines, pyrimidines, and the purine, adenine. In addition, acid hydrolysis produces a racemic mixture of biological and non-biological amino acids. Many of these molecules are implicated in the origin of life on Earth, suggesting Titan as a contemporary laboratory environment for prebiological organic chemistry on a planetary scale.

Synthesis and biological activity of 7 beta-(2-amino-2-carboxy)-ethylthioacetamido-7 alpha-methoxycephalosporin derivatives

C-7 and C-3 substituents of a new antibiotic SF-1623 were chemically modified to improve the bioactivity, and substituent effect at C-7 and C-3 was examined on the basis of MIC and ED50 values against selected bacteria. Among a large number of derivatives, MT-141 possessing 2-D-2-amino-2-carboxyethylthioacetamido residue at C-7 and N-methyltetrazolyl-thiomethyl residue at C-3 showed a high order of antibacterial activity in vitro and especially in vivo.

Canal diameter, anteroposterior compression ratio, and spondylotic myelopathy of the cervical spine

Nine patients with cervical spondylotic myelopathy, diagnosed during life, were subjected to detailed clinicopathologic study. The degree of cord destruction was in good correlation with the ratio of the anteroposterior diameter to the transverse diameter, designated as an anteroposterior compression ratio. Within the factors responsible for decrease in the ratio, developmental narrowing of the spinal canal was the most significant, and multiplicity of spondylotic protrusion less so. The former resulted in an extensive demyelination of the posterolateral funiculus and infarction of the gray matter. Recurrent trauma proved to cause distinct manifestations and cord pathology. Clinicopathologic correlations were also examined from the neurologic findings at the terminal stage.

Modification of the macrolide antibiotic midecamycin. III. Formation of neoisomidecamycin

Treatment of 9-trichloroacetylmidecamycin with aqueous alkali gave an isomer of midecamycin (neoisomidecamycin), in which one double bond underwent allylic rearrangement. The formation of neoisomacrolides was dependent on the nature of protective groups and conditions of deprotective reaction. Treatment of 9-trichloroethoxycarbonylmidecamycin with Zn/acetic acid resulted in no allylic rearrangement.

Studies on SF=1902 A2 A5, minor components of SF-1902 (globomycin)

Four members of globomycin, SF-1902 A2, A3, A4a and A4b were newly isolated from the culture of Streptomyces hygroscopicus SF-1902. These minor components shared four amino acids in common and the fifth was either valine or allo-isoleucine. The fatty acid moiety varied from 3-hydroxy-2-methylheptanoic acid in A2 to 3-hydroxy-2-methylundecanoic acids in A4b. The length of alkyl chain greatly affected the antibacterial activity, and maximum activity was shown by the homologue (A5) possessing the longest alkyl chain.

Oligostatins, new antibiotics with amylase inhibitory activity. I. Production, isolation and characterization

Oligostatins C, D and E, three new antibiotics were found in the culture filtrate of Streptomyces myxogenes nov. sp. SF-1130. Their spectral and chemical properties suggested that oligostatins were basic oligosaccharide antibiotics. They exhibited not only antibacterial activity but also strong amylase inhibitory activity.

SF-1961, a new antibiotic related to bleomycin

A new type of bleomycin group antibiotic, SF-1961 was isolated from the fermentation broth of Streptomyces species. SF-1961 possessed beta-amino-beta-(4-amino-6-carboxypyrimidin-2-yl)-propionic acid instead of its 5-methyl derivative which was a common component of bleomycins and phleomycins.

Changes in molecular species of rat liver choline glycerophospholipids with development

Molecular species of rat liver choline glycerophospholipids were investigated at various stages of development by a gas chromatograph-mass spectrometer system. They were composed mainly by 1,2-diacyglycerophosphocholine and changed with development particularly during the perinatal period.. In the prenatal period, the major species were '32 : 0' (mainly 16 : 0/16 : 0, dipalmitoyl species), '34 : 0' (mainly 16 : 0/18 : 0, palmitoystearoyl speciesY, '34 : 1' (mainly 16 : 0/18 : 1, palmitoyloleoyl species) and '34 : 2' (mainly 16 : 0/18 : 2, palmitoyllinoleoyl speciesY and '32 : 0' decreased rapidly and '34 : 1' increased as the stage proceeded. After birth, however, polyunsaturated species such as '34 : 4' and '38 : 4-6' increased rapidly in contrast to the decrease of '32 : 1, 34 : 1, 36 : 1, and 34 : 0'. Moderate changes were observed in these species during subsequent development.

Evoked spinal potentials as a monitor of spinal cord viability

To determine the diagnostic and prognostic significance of evoked spinal potentials (ESPs), reproducible, compressive spinal cord lesions were produced in dogs under ESP monitoring. Both motor recovery and histologic findings were investigated in relation to the amplitude and persistence of the ESPs. Animals that had moderate, anterior compression (51% of canal width) in which the ESP was maintained had considerable motor recovery. Among animals that had submaximal compression (60%), motor recovery was good in those with persistent ESPs. The compression ratio at which ESPs terminated (67%) was termed the "electrophysiologic maximum tolerable compression." Continuous ESP expiration resulted in irreversible lesions and loss of motor recovery. Compressive spinal cord lesions of reproducible, graded severity were employed for the first time in our study of ESP. Persistence and amplitude were both useful in predicting not only the severity and extent of this type of lesion but also the recovery.

Studies on molecular species of choline glycerophospholipids of developing rat brain

The chronological changes in molecular species of choline glycerophospholipids were studied for cerebra of 17-, 19- and 21-day-old rat fetuses, and 3-, 6-, 12-, 24- and 90-day-old rats. The molecular species found by gas chromatography-mass spectrometry and selected ion retrieval technique were phosphatidylcholines of '30 : 0, 32 : 0, 32 : 1, 34 : 0, 34 : 1, 34 : 2, 36 : 0, 36 : 1, 36 : 2, 36 : 3, and 36 : 4' where the larger number indicates the sum of chain lengths on positions C-1 and C-2; the smaller number is the total number of double bonds. Of these molecular species, '32 : 0' (mainly 16 : 0/16 : 0, dipalmitoyl glycerophosphorylcholine), '34 : 1' (mainly 16 : 0/18 : 1, palmitoyloleoyl glycerophosphorylcholine), '34 : 0' (16 : 0/18 : 0, palmitoylstearoyl glycerophosphorylcholine), '32 : 1' (mainly 16 : 0/16 : 1, palmitoylpalmitoleoyl glycerophosphorylcholine and '30 : 0' (14 : 0/16 : 0, myristoylpalmitoyl glycerophosphorylcholine) were main species. The '32 : 0' species increased to about 44% at around the 10th day and thereafter remained nearly constant. '34 : 1' and '34 : 0' decreased to about 17 and 6% at that time and then increased to about 30 and 14%, respectively. '30 : 0' increased from last stage of gestation to the 6th day and then decreased. '32 : 1' was about 16% for 17-day-old fetus and decreased grandually. '36 : 1' (18 : 0/18 : 1, stearoyloleoyl glycerophosphorylcholine) increased at the latter part of development.

Studies of molecular species of fetal lung lecithins by gas-liquid chromatography mass spectrometry

The molecular species of lung lecithins obtained from rabbit and rat fetuses at different days of gestation and from newborns were analysed as TMS derivatives of the corresponding diglycerides in a gas chromatograph mass spectrometer system by selected ion retrieval. In the latter part of gestation, the order of the main molecular species of lung lecithins, PCn, was PC32 greater than PC34 greater than PC30, while at an earlier stage it was PC34 greater than PC32 greater than PC30. During gestation the change of PC32:0, dipalmitoyllecithin, was remarkable. Ether lecithins are also discussed.

Congenital hypocupraemia syndrome with and without steely hair: report of two Japanese infants

Two Japanese infants with Menke's kinky hair syndrome are reported. The unusual finding in one infant was the absence of the hair abnormality characteristic of this disease; other findings were consistent with the diagnosis. It is suggested that hair abnormality cannot be relied upon for the diagnosis and that the term "kinky hair" is anappropriate. In its place "congenital hypocupraemia" is proposed as the diagnostic term to embrace patients with and without hair abnormality. Serum copper determination is a simple and reliable test in the diagnosis of this syndrome and should be done routinely in all male patients with unexpected deterioration. The angiographic features present in these patients with unexpected deterioration. The angiographic features present in these patients are characteristic but not pathognomonic of the disease. Subdural hygroma, a common finding, is the result of severe brain atrophy and little can be expected by surgical intervention.

Congenital brain defect masked by subdural fluid collection

Two rare cases of subdural fluid collection are reported. In these cases, the subdural space was in direct communication with the lateral ventricle through the congenital brain defects. The subdural fluid was formed by the cerebrospinal fluid which passed from the lateral ventricle through the brain defects. The difficulty to diagnose these cases from the usual subdural hygroma is emphasized.