Fatty acid composition of membranes of L-forms ofStreptococcus faecalis andProteus mirabilis cultured at different osmolalities

The fatty acid composition of membranes of L-forms ofStreptococcus faecalis andProteus mirabilis cultured at different osmolalities and in different osmotic stabilizers was examined.S. faecalis L-forms cultured with sucrose in the medium showed a decrease in the unsaturated fatty acid C₁₈₁ and an increase in the C₁₈ fatty acid and C₁₉ cyclopropane fatty acid. Fatty acid composition ofS. faecalis L-forms cultured in medium containing 1.8% NaCl was similar to the fatty acid composition of L-forms cultured in brain-heart infusion broth (BHI) without osmotic stabilizer and was between the composition of fatty acids of L-forms in BHI with sucrose and that in BHI without 0.5 M sucrose. InProteus mirabilis L-forms, there were differences between L-forms cultured with and without sucrose, but these differences were not comparable to the changes observed inS. faecalis L-forms.P. mirabilis L-forms cultured with and without NaCl in the medium had similar fatty acid compositions.     

Epidémie de dysentérie bacillaire.

An outbreak of bacillary dysentery in 1978 affecting 928 persons, most of whom were living in the village of St-Jacques, PQ, is described. An epidemiologic study suggested the water supply as the source of the infection, and it was established that the water carried by the municipal aqueduct was contaminated by feces containing the causal agent, Shigella sonnei. This epidemic, the largest mentioned in he Canadian medical literature, demonstrates how contagious this infection is.     

The usefulness of the analytical electrofocusing in a thin-layer polyacrylamide gel (PAG) in the histochemistry of enzymes cleaving peptide bonds

Summary The usefulness of the analytical electrofocusing in a thin-layer polyacrylamide (PAG) plate is shown on the basis of experiments with 10%–20% homogenates of various rat, rabbit and human organs as well as in lysates of isolated human lymphocytes and leucocytes in 2% Triton X100. 0.1–0.3 l of 12000 g supernatants were applied on LKB Ampholine PAG plates pH range 3.5–9.5 and subjected to electrofocusing. Afterwards portions of PAG plates were processed in optimized histochemical media for the demonstration of enzymes cleaving peptide bonds using various substrates. The same media were used in the histochemical detection of enzymes in sections on slides or semipermeable membranes. Electrofocused zymograms display species and organ differences. Ala-MNA, Leu-MNA and Met-MNA furnish similar zymograms. Bands obtained with Ala-MNA are most intense. Zymograms with Gly-Pro-MNA and Lys-Pro-MNA at pH 7.2 are not entirely identical. The majority of bands is more intense when Gly-Pro-MNA is used as the substrate and is due to the activity of DAP IV. The anodal band(s) focusing around pH 4.9 (rat) or 5.5 (man) is (are) much stronger with Lys-Pro-MNA and DAP II is responsible for it (them). Zymograms with His-Ser-MNA and Lys-Ser-MNA are similar. However, they differ form those revealed with Gly-Pro-MNA and Lys-Pro-MNA. Zymograms of lysates of leucocytes obtained with naphthol AS-D-chloroacetate and Ac-Ala-l-naphthyl ester are not identical showing that more than one enzyme is responsible for the bands. Results obtained with closely related substrates such as Ac-Ala-l-naphthyl ester and Ac-Met-l-naphtyl ester are not identical either. Zymograms of lysates of human lymphocytes revealed with Gly-Pro-MNA at pH 7.2 and Lys-Ala-MNA or Lys-Pro-MNA at pH 5.5 or 5.3 respectively show clearly the presence of DAP IV and DAP II in these cells. The analytical electrofocusing in PAG plates is a very useful tool in the histochemistry (and biochemistry) of enzymes cleaving peptide bonds. It helps very much in the evaluation of the substrate specificity, choosing of the discriminating substrate and enables a quick and reliable testing of the quality of various batches of commercially supplied substrates, diazonium salts and other reagents. The correlation of zymograms with the in situ pattern helps in the elucidation of the origin of individual bands in zymograms and suggests different molecular forms of peptidases in different localizations.     

Vitamin A toxicity and hypercalcaemia in chronic renal failure.

Serum vitamin A concentrations were measured in 38 patients undergoing haemodialysis, 24 of whom were taking multivitamin preparations containing vitamin A. Vitamin A concentrations were significantly higher in patients undergoing haemodialysis than in 28 normal controls (p less than 0.001). Patients taking vitamin A supplements had significantly higher vitamin A concentrations than those not taking them (p less than 0.05), and hypercalcaemic patients had higher concentrations than normocalcaemic patients (p less than 0.005). Withdrawal of vitamin A supplements in seven patients caused significant falls in serum vitamin A concentrations and plasma calcium concentrations (p less than 0.01 at two and three months in both cases) and in plasma alkaline phosphatase concentrations (p less than 0.01 at two months). Vitamin A toxicity can contribute to hypercalcaemia in patients undergoing haemodialysis, probably by an osteolytic effect. Multivitamin preparations containing vitamin A should therefore be prescribed with caution in these patients.     

Nutritional and karyotypic characterization of a haploid cell culture ofDaucus carota

Summary The purpose of this study was to optimize growth conditions for a strain of haploid carrot callus and to follow its karyotypic changes in a long span of time. The strain has been maintained in liquid suspension since September 1977. It has remained predominantly haploid in its karyotype since that time. The original explant was initiated and subsequently subcultured in Gamborg's B5 medium. The components of the B5 medium were omitted one at a time and sequentially added back to determine their minimum, optimum, and maximum nontoxic concentrations. These changes were made in the original formula: the addition of an organic buffering agent and an increase in the iron and other micronutrient concentrations. Using this slightly modified B5 medium, we assessed the effect on growth by single additions of amino acids, different carbon sources, growth regulators, and vitamins. No improvement in plating efficiency resulted from addition of any of these compounds. We conclude that there are factors limiting the plating efficiency of the haploid cells other than these tested, or that single additions will not make a discernible difference, or that growth promoting factors cannot be exogenously supplemented to cultured cells.     

Structure of rigid-layer of Rhizobium cell wall. I. Purification on the peptidoglycan from the cellulose microfibrils

The bag shaped peptidoglycan layer of Rhizobium cell wall was isolated from intact cells after treatment with sodium dodecylsulfate and trypsin, chymotrypsin or pepsin digestion. Results of chemical analysis of acid hydrolyzed peptidoglycan revealed beside two amino sugars: glucosamine and muramic acid, three major amino acids; alanine, glutamic acid and 2,6-diaminopimelic acid and also significant amount of glucose. Evidence were provided that the polyglucose found in peptidoglycan preparations of three strains of Rhizobium trifolii, one of Rhizobium leguminosarum and one of Rhizobium meliloti consist of cellulose microfibrils. The content of cellulose present in Rhizobium peptidoglycans ranged from 60 to 80%. Methods of peptidoglycan purification from the cellulose microfibrils are described.     

Ethanol production from sugar cane segments in a high solids drum fermentor

Summary A successful yeast fermentation for the production of relatively high concentration of ethanol (9% w/v) was carried out using sugar cane segments. Extraction of sugar from segments occurred simultaneously with ethanol formation. The beer produced was transferred to a fresh batch of sugar cane segments and the fermentation cycle was repeated successively three times with the same beer. A high cane to water ratio was obtained in a rotating drum fermentor which allowed for a minimal amount of liquid to be used during the fermentation process.     

Effect of an exercise run to exhaustion on cAMP in the rat heart

The purpose of this investigation was to determine whether adenosine 3',5'-cyclic monophosphate (cAMP) content is increased in vivo in the heart as a result of exercise at a time when there is rapid cardiac glycogen utilization. Rats were run to exhaustion on a treadmill for a period of 164.5 +/- 9.5 min. Blood norepinephrine and epinephrine were significantly elevated approximately 2.5-fold above resting levels at the end of the treadmill run. Myocardial glycogen was reduced by 54.7% at exhaustion compared with control values. Myocardial cAMP was significantly elevated 88% above control levels as a result of the run. Associated with the depletion of myocardial glycogen and the elevation of cAMP was an activation of phosphorylase to its a form. These data suggest that myocardial glycogen metabolism during exercise is, in part, mediated by hormonal influences that are associated with increases in cAMP.     

Crucisoma bernardi n.g., n.sp. (Crustacea: Copepoda) parasitic in a deep-sea mollusc Cuspidaria filatovae Bernard, 1979 (Bivalvia: Anomalodesmata)

Summary Crucisoma bernardi, a copepod parasitizing a deepsea mollusc, Cuspidaria filatovae (Bivalvia: Anomalodesmata) off the coast of Oregon, is described and illustrated. A definitely poecilostomatoid copepod, belonging to a new genus, this species is treated by the author as incertae sedis, although there are many reasons why it should provide grounds for the erection of a new family. ac]19810127     

Desmosines in human urine. Amounts in early development and in Marfan''s syndrome.

Desmosines from 24 h human urine samples were isolated, characterized and quantified. The desmosines are in peptidyl form (1000--1500 molecular weight), and their amount is decreased by two-thirds between 7 and 25 years of age. Patients with Marfan's syndrome have significantly lower urinary amounts of desmosines than do comparable controls during the early development period.