Effect of thyroidectomy and adrenalectomy on changes in liver glutathione and malonaldehyde levels after acute ethanol injection

At low concentrations ethanol is metabolized largely by alcohol dehydrogenase to acetaldehyde, while at higher concentrations a microsomal ethanol oxidising system (MEOS) is involved, namely cytochrome P450 IIE1, which also probably generates free radical species. In hyperthyroidism hepatic glutathione stores are depleted and net superoxide anion production occurs. In contrast, in hypothyroidism hepatic glutathione may be increased and thus renders the liver less sensitive to alcohol generated free radical production. Steroid hormones inhibit lipid peroxidation. Sixty male Wistar rats either underwent thyroidectomy, adrenalectomy, or sham procedures. Twenty control animals were pair fed with thyroidectomized animals, whilst another twenty fed ad libitum. An intraperitoneal injection of alcohol (75 mmol/kg) was given 2.5 h prior to sacrifice to half the animals in each group, the remainder receiving saline. The total hepatic glutathione contents of the pair fed and the ad libitum groups were not different, but were significantly increased by thyroidectomy (p = <0.001). This effect was significantly reduced by alcohol (p < 0.01). The sham procedures and dietary restrictions had no effect. The ethanol alone reduced total hepatic glutathione, but this only reached statistical significance in the thyroidectomized and sham-adrenalectomized groups. Hepatic malonaldehyde (MDA) levels were significantly reduced in the thyroidectomy group but alcohol had no effect on them. We conclude that hypothyroidism increased hepatic glutathione status, presumably by reducing radical production by enzyme systems, which would otherwise consume this important scavenger. Long term exposure to ethanol with induction of MEOS is probably required for it to generate toxic levels of free radical species.     

PROTEOLIPID PROTEIN: SYNTHESIS AND ASSEMBLY INTO QUAKING MOUSE MYELIN

The incorporation of radioactive glycine into the major myelin proteolipid protein isolated from whole brain and from purified myelin of Quaking mice and normal littermates was compared. In a typical experiment, four Quaking mice and four littermate controls were injected intracranially with 250 μCi [2-³H]glycine and 25 μCi [U-¹⁴C]glycine respectively. Three hours later, the eight mice were killed and their brains combined. Equivalent portions were taken for (1) chloroform-methanol (2:1) extraction followed by ether precipitation of proteolipid from the brain and (2) myelin preparation. The ^3H/¹⁴C ratios for the microsomes:, the major myelin proteolipid as well as the other non-myelin proteolipids extracted from whole brain was approx 3.0. while the ³H/¹⁴C ratio for proteolipid protein in myelin was near 0.4. These findings were consistent for ages studied between 18 and 90 days. The results indicate that the synthesis of the major myelin proteolipid protein in the whole brain of Quaking mouse, as seen previously in our studies on basic protein, proceeds at a normal rate relative to microsomes but its incorporation into myelin is depressed. A working hypothesis of myelin membrane assembly is presented to account for the defect in the incorporation of these proteins into Quaking myelin.     

The inhibitory effect of ethanol on ethanol production by Zymomonas mobilis

Summary In an effort to establish the reasons for the limitations in the final ethanol concentration of Zymomonas mobilis fermentation, the effects of CO₂ and ethanol on the fermentation were investigated using continuous and fed-batch cultivation systems. The nucleation and stripping out of CO₂ from the fermenter using diatomaceous earth or nitrogen gas or both exhibited a profound effect on the glucose uptake rate during the early stages of fed-batch fermentation, but did not improve final ethanol yields. The addition of ethanol together with above mentioned experiments confirmed conclusively that ethanol inhibition is responsible for the final ethanol concentration obtainable during Zymomonas mobilis fermentation. The final concentration lies between 90 and 110 gl⁻¹ or approximately 12–15% (v/v) ethanol.     

A semimechanistic mathematical model for growth of Rhizopus oligosporus in a model solid-state fermentation system

A Semimechanistic mathematical model is developed which describes the growth of Rhizopus oligosporus in a model solid-state fermentation system. Equations are presented for the release of glucoamylase, the diffusion of glucoamylase, the hydrolysis of starch, the generation and diffusion of glucose, and the uptake of glucose and conversion into new biomass. Good agreement of the model with the experimental data was obtained only after the glucoamylase diffusivity and the maximum specific glucose uptake rate were altered from their originally determined values. The model recognizes the distributed nature of the solid-state fermentation and therefore is able to predict the concentration profiles of the system components within the substrate. The model provides an insight into the possible rate-limiting steps in solid-state fermentation-the generation of glucose within the substrate and the resulting availability of glucose at the surface.     

Spirits and spiritist therapy in Southern Brazil: A case study of an innovative,syncretic healing group

This paper examines the treatment of patients by a group of Spiritist healers in southern Brazil. After describing and analyzing a healing session, the practices are shown to be deviant from conventional Spiritism in two directions: (1) they employ a technique, called apometry, that they claim makes possible the transportation of a part of the patient's body to the astral world where it is treated by disincarnate doctors who do past life regressions; and (2) although a conventional Spiritist disobsession is performed, the healers invoke rival Afro-Brazilian spirits who often are shown to have caused the patient's symptoms.Building on the work of Csordas (1983), 1 hypothesize that the discourse employed by the healers moves the patient to a new reality or phenomenological world in which s/he is healed not in the sense of being restored to the state in which s/he existed prior to the onset of illness, but in the sense of being rhetorically moved into a state dissimilar from both pre-illness and illness reality... (Csordas 1983:346). The new state, in this case, is the world of Spiritism. Unlike the Catholic Pentecostals Csordas studied who already were members of a primary group of believers, however, the patients treated by the Brazilian healers are mostly unaffiliated individuals who face the increasing uncertainty and insecurity of life in disorganized, anomic, urban Brazil. By encompassing modern science on the one hand, and aspects of the Afro-Brazilian traditions on the other, this healing group appeals to the often distraught white middle and lower-middle classes, providing them with therapeutic meaning that in many cases leads to healing, conversion, and the sense of security and safety that often accompanies identifying with and belonging to a religious group.     

The araC regulatory gene mRNA contains a leader sequence

Summary An estimation of the size of the araC gene in Escherichia coli B/r was made by sub-cloning restriction fragments of the araC-containing hybrid plasmid pTB1 into the plasmid pBR322. Plasmids which contained a functional araC gene were identified by genetic complementation tests. DNA sequence analysis of the promoter-proximal region of the araC gene revealed that araC mRNA contains a 150 nucleotide leader.     

Dihydrofolate reductase from a methotrexate-resistant Escherichia coli: Proton magnetic resonance studies of complexes with folate and methotrexate

Proton magnetic resonance studies of 1:1 complexes of E. coli dihydrofolate reductase with folate and methotrexate were performed. A resonance at 1850 Hz in 1:1 enzyme-folate was assigned as the C-7 proton of bound folate by comparison with the spectra of enzyme complexed with folate specifically deuterated at C-7. The first order rate constant for folate dissociation was calculated to be less than 110 sec^?1. Four of the five histidine residues exhibited the same pK's and chemical shifts in the two complexes with pK values of 8.0, 7.3, 6.5 and ～5. However, one histidine increased its pK by 0.7 units (6.25→6.95) and its C-2 proton resonance shifted upfield 50 Hz when folate was substituted for methotrexate. Comparison of these results with those of chemical modification and ultraviolet difference spectroscopy experiments suggests that this histidine may be in the folate binding site — possibly near the pteridine portion of that site.     

Lipopolysaccharide and serum synergistically stimulate ornithine decarboxylase in Chinese hamster ovary cells

Lipopolysaccharide (LPS), the active component of bacterial endotoxin, caused no significant increase in ornithine decarboxylase (ODC) activity in serum-starved, Chinese hamster ovary fibroblasts. However, concurrent addition of LPS with 10% fetal bovine serum caused a synergistic 30 to 40-fold increase in enzyme activity as compared to the 10 to 20-fold increase seen after addition of serum alone. This synergism was not due to an alteration in the time course of enzyme induction after serum addition. The LPS-induced synergy of ODC induction by serum was inhibited by the concurrent addition of the specific LPS-antagonist, Polymyxin B.