Photochemical reactions in interstellar grains photolysis of co,NH3, and H2O

A simulation of the organic layer accreted onto interstellar dust particles was prepared by slow deposition of a CO:NH₃:H₂O gas mixture on an Al block at 10K, with concomitant irradiation with vacuum UV. The residues were analyzed by GC-MS, HPLC, and near IR; a reaction pathway leading from NH₃ to complex alcohol, fatty acid, and amide products in 27 stages is postulated. The astronomical relevance and significance of the observations are discussed.     

Ultrasonic radiation induced lipid peroxidation in liposomal membrane

Summary Ultrasonic radiation produced a dose dependent linear increase in lipid peroxidation (MDA formation) in the liposomal membrane. The yield of MDA was significantly inhibited by butylated hydroxytoluene (BHT), the antioxidant, sodium formate, the OH radical scavenger, and EDTA, the metal ion chelator. Ascorbic acid at low concentration increased the ultrasonic induced MDA formation while high concentrations inhibited lipid peroxidation. A mechanism of ultrasound induced lipid peroxidation is suggested.     

The structural gene for the mitochondrial aldehyde dehydrogenase maps to human chromosome 12

Summary A cloned 850 bp cDNA fragment corresponding to the 3-coding part of human ALDHI-mRNA was used as a probe for the chromosomal assignment of the ALDHI gene. Southern blot analysis of human-rodent somatic cell hybrids indicates that the human ALDHI gene resides on chromosome 12.Dedicated to Prof. Dr. H. Holzer on the occasion of his 65. birthday     

Association between transfusion of whole blood and recurrence of cancer.

Transfusion affects the immune response to renal transplantation and may be associated with recurrence of various human neoplasms. Data from patients with colonic, rectal, cervical, and prostate tumours showed an association between transfusion of any amount of whole blood or larger amounts of red blood cells at the time of surgery and later recurrence of cancer. Recipients of one unit of whole blood had a significantly higher incidence of recurrence (45%) than recipients of a single unit of red cells (12%) (p = 0.03). Recipients of two units of whole blood also had a higher rate of recurrence (52%) than those receiving two units of red cells (23%) (p = 0.03). Recipients of any amount of whole blood had similar recurrence rates (38-52%). Recipients of four or more units of red blood cells had a higher rate of recurrence (55%) than those receiving three or fewer units of red blood cells (20%) (p = 0.005). Mortality due to cancer in patients receiving three or fewer units of red blood cells (2%) was similar to that in patients who did not have transfusions (7%) and significantly lower than that observed in patients receiving three or fewer units of whole blood (20%) (p = 0.003). A proportional hazards risk analysis showed that transfusion of any whole blood or more than three units of red blood cells was significantly associated with earlier recurrence and death due to cancer. These data support an association between transfusion and recurrence of cancer. They also suggest that some factor present in greater amounts in whole blood, such as plasma, may contribute to the increased risk of recurrence in patients who have undergone transfusion. Until the questions raised by retrospective studies of cancer recurrence and transfusion can be answered by prospective interventional trials with washed red blood cells, red blood cells should be transfused to patients with cancer in preference to whole blood when clinically feasible.     

Fluidity,permeability and antioxidant behaviour of model membranes incorporated with α-tocopherol and vitamin E acetate

Magnetic resonance studies reveal a marked difference between the binding of α-tocopherol and that of the corresponding acetate (vitamin E acetate) with dipalmitoylphosphatidylcholine (DPPC) vesicles. This is reflected in differences in the phase-transition curves of the DPPC vesicles incorporated with the two compounds, as well as in the ¹³C relaxation times and line widths. A model for the incorporation of these molecules in lipid bilayers has been suggested. α-Tocopherol binds strongly with the lipids, possibly through a hydrogen bond formation between the hydroxyl group of the former and one of the oxygen atoms of the latter. The possibility of such a hydrogen bond formation is excluded in vitamin E acetate, which binds loosely through the normal hydrophobic interaction. The model for lipid-vitamin interaction explains the in vitro decomposition of H₂O₂ by α-tocopherol. α-Tocopherol in conjuction with H₂O₂ can also act as a free-radical scavenger in the lipid phase. The incorporation of α-tocopherol and vitamin E acetate in DPPC vesicles enhances the permeability of lipid bilayers for small molecules such as sodium ascorbate.     

Studies in antifertility agents — Part XLI: Secosteroids — X: Syntheses of various stereoisomers of (±) 2,6β-diethyl-7α-ethynyl-3-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol

The syntheses of (±) 2α,6β-diethyl-7α-ethynyl-3α-($\text{p}$-hydroxyphenyl)-$\text{trans}$-bicyclo[4.3.0]nonan-7β-ol ($\text{8}$), (±)2β,6β-diethyl-7α-ethynyl-3β-($\text{p}$-methoxyphenyl)-$\text{trans}$-bicyclo[4.3.0]nonan-7β-ol ($\text{12}$) and (±) 2α,6β-diethyl-7α-ethynyl-3β-($\text{p}$-hydroxyphenyl)-$\text{trans}$-bicyclo[4.3.0]nonan-7β-ol ($\text{18}$) and their derivatives, which are essentially B-seco-steroids having $\text{cis-anti-trans}\text{,}\text{cis-syn-trans}$ and $\text{trans-anti-trans}$ geometries have been carried out. A study of their antiimplantation activities (AI) and receptor binding affinities (RBA) show that $\text{trans-anti-trans}$ compounds are biologically most potent, followed by the corresponding $\text{cis-anti-trans}$ and $\text{cis-syn-trans}$ compounds. The most potent compound $\text{18}$ is active at 1 mg/kg in rats. Introduction of 7α-ethynyl group increases their AI activity; however, no significant effect on their RBA is observed.     

Amino acid sequence of the active site of human pseudocholinesterase

The usualE ₁ ^u and atypicalE ₁ ^a human pseudocholinesterases (acylocholine acylhydrolase, EC 3.1.1.8) were purified to homogeneity. The active-site serine residue was conjugated with diisopropyl fluorophosphate and digested with trypsin. The tryptic peptide containing the active site was isolated by gel filtration followed by two-dimensional paper chromatography and electrophoresis. The amino acid sequence of the active site peptide obtained from the usualE ₁ ^u enzyme was found to be Gly-Glu-Ser-Ala-Gly-Ala-Ser-Ala-Val-Ser-Leu. A remarkable structural homology exists between the human and the horse enzymes in their active sites. From the difference in electrophoretic mobility of the active-site peptides obtained from the usual and atypical enzymes, the probable structure of the atypical human enzyme was deduced as Gly-His-Ser-Ala-Gly-Ala-Ser-Ala-Val-Ser-Leu.     

Increased osmotic tolerance of some Aspergilli isolated from ‘Usar’ (alkaline) soils — A possible indication of ecological specialization

Studies on the osmotic optima for growth of some Aspergilli isolated from Indian Usar (alkaline) soils have revealed the occurrence of four osmophilic and twenty-five other species which can be categorised as facultative tolerant on the basis of their osmotic concentration optima. In addition, the Usar soil strains possess a comparatively greater osmotic tolerance than their fertile soil counterparts which may be attributed to the relatively hypertonic conditions prevailing in Usar soils.     

Effect of apholate and hempa on nucleic acid and protein syntheses in the yellow-fever mosquito

The growth curve, nucleic acid and protein content of the various life stages of Aedes aegypti were studied. The larvae of this mosquito were treated with sterilizing doses of the chemosterilants apholate and hempa, and their effects on the above parameters were also investigated. The body-weight increased gradually in the earlier instars and showed a sharp rise from late-fourth instar to the pupa. Adults weighed less than the pupae. Females weighed more than the males. In the controls, DNA and RNA content generally followed the growth curve. RNA content was more than DNA up to the late-fourth instar and the ratio reversed in the later stages. Protein content also followed the growth curve except in adult female, where it was more than in the pupa. In general the treatment with the chemosterilants, apholate and hempa did not seem to alter RNA, DNA and protein content in the whole insect.

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Zusammenfassung Wachstumskurve, Nukleinsäure- und Eiweißgehalt verschiedener Entwicklungsstadien der Gelbfieber-Mücke, Aedes aegypti, wurden untersucht. Die Larven dieser Mücke wurden mit sterilisierenden Dosen der Chemosterilantia Apholate und Hempa behandelt und ihre Wirkungen auf die genannten Parameter geprüft. Das Körpergewicht nahm in den frühen Stadien allmählich zu und zeigte vom Ende des 4. Stadiums bis zur Puppe einen steilen Anstieg. Adulte wogen weniger als die Puppen, Weibchen mehr als Männchen. In den Kontrollen folgte der DNS- und RNS-Gehalt im allgemeinen der Wachstumskurve. Der RNS-Gehalt war bis zum späten 4. Stadium größer als der DNS-Gehalt, in den späteren Stadien kehrte sich das Verhältnis um. Der Eiweißgehalt folgte ebenfalls der Wachstumskurve mit Ausnahme bei den Weibchen, wo er höher war als in der Puppe. Im allgemeinen schien die Behandlung mit den Chemosterilantien Apholate und Hempa den RNS-, DNS- und Eiweißgehalt im ganzen Insekt nicht zu verändern.