326
|
Hughes WH, Hill MJ. Variation in distribution of inducible enzyme in pure clones of bacteria. Nature 1968; 218:766-8. [PMID: 4871056 DOI: 10.1038/218766a0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
327
|
Hill MJ, Wannamaker LW. The serum opacity reaction of Streptococcus pyogenes: general properties of the streptococcal factor and of the reaction in aged serum. J Hyg (Lond) 1968; 66:37-47. [PMID: 4869017 PMCID: PMC2130610 DOI: 10.1017/s0022172400040924] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
SUMMARYThe capacity of certain strains ofStreptococcus pyogenesto produce opacity in aged horse serum has been studied. Cells from all stages of the growth cycle are able to produce opacity. Maximal activity is reached towards the end of the exponential phase of growth.Examination of cell fractions obtained by mechanical breakage and differential centrifugation suggested that the cell-bound activity is predominantly associated with the membrane fraction. Extraction with sodium deoxycholate yields a soluble fraction of high activity.There is considerable strain variation in heat stability of the serum opacity factor. Cell-bound activity is often quite resistant to heat, whereas extracted activity is less stable.Low concentrations of divalent cations have an activating effect, whereas high concentrations inhibit the serum opacity reaction. High concentrations of uni-valent cations are without effect on the cell-free enzyme but have an activating effect on the cell-bound enzyme.For both the cell-bound and the cell-free enzyme the pH optimum was 5·8.Although sensitive to trypsin and pepsin, the serum opacity factor appears to be resistant to streptococcal proteinase. Its activity is destroyed by formaldehyde and by periodate but is unaffected by a number of reducing agents.Pre-heating of the serum or the addition of iodoacetate did not affect the serum opacity reaction. The enhanced cholesterol esterification previously described with fresh serum appears to be a secondary reaction. Even when isolated by relatively gentle methods, α-lipoprotein serves as a substrate only in the presence of crystalline serum albumin.
Collapse
|
328
|
Hill MJ, Holt DB, Unvala BA. Automatic jet thinning of GaAs for transmission electron microscopy. JOURNAL OF SCIENTIFIC INSTRUMENTS 1968; 1:301-2. [PMID: 5649282 DOI: 10.1088/0022-3735/1/3/307] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
330
|
Hill MJ, Drasar BS. Bacterial degradation of bile salts. Biochem J 1967; 104:55P-56P. [PMID: 6049892 PMCID: PMC1271305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
332
|
Hill MJ, Blane HT. Evaluation of psychotherapy with alcoholics. A critical review. QUARTERLY JOURNAL OF STUDIES ON ALCOHOL 1967; 28:76-104. [PMID: 5339893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
333
|
Hill MJ, Wilkins K. An instrument for the semi-automatic reading of film badges used in personal radiation monitoring. JOURNAL OF SCIENTIFIC INSTRUMENTS 1966; 43:517-8. [PMID: 5945257 DOI: 10.1088/0950-7671/43/8/311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
334
|
Hill MJ, Pownall DR. Modification of a Baldwin radiological densitometer to measure densities up to 7.5. Br J Radiol 1966; 39:633-5. [PMID: 5944506 DOI: 10.1259/0007-1285-39-464-633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
|
336
|
James AM, Hill MJ, Maxted WR. A comparative study of the bacterial cell wall, protoplast membrane and L-form envelope of Streptococcus pyogenes. Antonie Van Leeuwenhoek 1965; 31:423-32. [PMID: 5329494 DOI: 10.1007/bf02045921] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|