Introduction of a Micrococcus plasmid in Escherichia coli

A 6-MDa plasmid (pMQV10), carrying cholesterol hydroxylase and streptomycin-resistance genes, from a gram-positive strain of Micrococcus sps., (RJ6) has been successfully transformed in gram-negative Escherichia coli K12 C600. pMQV10 is maintained stably and expresses its drug resistance in the new host.     

Effect of short-chain organic acids on macromolecular synthesis in Escherichia coli

Incubating cultures of Escherichia coli with propionic acid (5 mmol/l) or formic acid (10 mmol/l) at pH 5.0 produced bacteriostasis lasting 30 and 120 min respectively. During this time rates of RNA, DNA, protein, lipid and cell wall synthesis were reduced. Growth resumed after continued incubation in the presence of acid, but cells from acid-treated cultures were larger than controls. DNA synthesis was particularly sensitive to the presence of the propionic or formic acid.     

Denatured proteins are degraded more rapidly than abnormal proteins in cell-free extracts ofSaccharomyces cerevisiae

Abnormal proteins synthesized in the presence of ethionine were degraded more rapidly than the normal ones in cell-free extracts of ethanol-grown yeast. The denatured proteins, however, were degraded in preference to their native counterparts which were either normal or abnormal. Participant of the UNESCO course “On Modern Problems in Biology and Microbial Technology”.     

Fine needle aspiration cytology of alveolar soft-part sarcoma. A case report

A fine needle aspiration specimen from a mass in the thigh of a 25-year-old woman was submitted for cytologic examination. Malignant cells were found singly and in well-defined nests, resulting in an alveolar pattern. Individual cells were large, with moderate amounts of granular cytoplasm and vesicular nuclei with prominent nucleoli. The aspiration cytology findings plus the clinical setting suggested an alveolar soft-part sarcoma. Histologic and electron microscopic examination of the tumor mass confirmed the diagnosis.     

COMPARATIVE PROLIFERATIVE KINETICS OF CELLS FROM NORMAL HUMAN EPIDERMIS AND BENIGN EPIDERMAL HYPERPLASIA (PSORIASIS) IN VITRO

Proliferation kinetics of epidermal cells from normal human skin and lesions of psoriasis (benign epidermal hyperplasia) were studied in vitro. Epithelial out-growths were obtained from skin explants and the cell cycle studied using the conventional method of following two successive curves of labeled mitoses after an initial pulse with ³H thymidine. The length of T_c was 59 hr and 53.5 hr respectively for normal and psoriatic cells. The shorter T_c for psoriasis was due to a shorter duration of S. The growth fraction was 66% and 74% for normal and psoriatic cells respectively as determined by continuous labeling with ³H thymidine. Under the conditions of the present experiments, therefore, normal and psoriatic epidermal cells showed no significant difference in proliferative capacity.     

Factors affecting lipase production in Syncephalastrum racemosum

Syncephalastrum racemosum grown as a static culture showed maximum lipase production at 30°C in 2d at pH 8.0. When the medium was supplemented with fructose, maximum production of lipase per unit of growth was achieved, followed by raffinose, sucrose, ribose, galactose, maltose, lactose, mannitol and glucose. Amongst the nitrogen sources tested, corn steep liquor at 8% (v/v) produced maximum enzyme; there was evidence of catabolite repression by glucose when groundnut protein, soybean meal, milk casein or wheat bran were the sources of nitrogen. Calcium, potassium and sodium citrates, each at 0.1% (w/v), increased the yield of lipase.     

Cardiac Monitoring in a Regional Hospital

The first 18 months'' experience in a self-contained, 9-bedded cardiac monitoring unit in a regional general hospital is reported. Of 667 admissions, 373 (56%) had acute myocardial infarction. Of these, 61 (16%) patients suffered cardiac arrest(s), and 11 were successfully resuscitated. The overall mortality was 13.4%, which compares favourably with other series reported.     

Solution Structures of Rat Amylin Peptide: Simulation, Theory, and Experiment

Amyloid deposits of amylin in the pancreas are an important characteristic feature found in patients with Type-2 diabetes. The aggregate has been considered important in the disease pathology and has been studied extensively. However, the secondary structures of the individual peptide have not been clearly identified. In this work, we present detailed solution structures of rat amylin using a combination of Monte Carlo and molecular dynamics simulations. A new Monte Carlo method is presented to determine the free energy of distinct biomolecular conformations. Both folded and random-coil conformations of rat amylin are observed in water and their relative stability is examined in detail. The former contains an α-helical segment comprised of residues 7-17. We find that at room temperature the folded structure is more stable, whereas at higher temperatures the random-coil structure predominates. From the configurations and weights we calculate the α-carbon NMR chemical shifts, with results that are in reasonable agreement with experiments of others. We also calculate the infrared spectrum in the amide I stretch regime, and the results are in fair agreement with the experimental line shape presented herein.