Search PubMed⌕ Search

Biomedical subjects

M Hughes

Publications and source records attributed to M Hughes.

At least 235 records · Page 13Linked to original sources
PubMed1979

Intracellular localization of 55Fe after serum-mediated uptake by human erythropoietic cells.

Marrow cells of 3 patients with normoblastic erythropoiesis and 1 with sideroblastic erythropoiesis were incubated with serum-bound 55Fe Cl3 and studied by the technique of electron microscope autoradiography. In the 3 normoblastic marrows, both the mean grain counts and the percentages of grains situated over the cytoplasm (excluding the mitochondria) were higher in the early erythroblasts than in the intermediate and late erythroblasts. The percentages of autoradiographic grains situated over the mitochondria of early intermediate and late erythroblasts were 11.9-27.4, 56.5-61.1 and 65.3-65.9, respectively. Although the mean grain counts over these three cell classes in the sideroblastic marrow were similar to those in the normoblastic marrows, the proportions of grains over the mitochondria were higher, particularly in the early erythroblasts. In all 4 cases (1) some grains were situated at the junction between heterochromatin and euchromatin and (2) a few of the 55Fe-labelled immature-looking cells did not display the ultrastructural features usually attributed to pronormoblasts.

Adult↗
PubMed1978

High resolution autoradiographic studies of RNA, protein and DNA synthesis during human eosinophil granulocytopoiesis: evidence for the presence of RNA on or within eosinophil granules.

Human bone marrow cells which had been incubated with [3H]uridine or [3H]leucine for I h were studied using the technique of electron microscope-autoradiography. The autoradiographs revealed the presence of newly-synthesized RNA and protein molecules within or on a proportion of (I) the primary and secondary granules in all classes of eosinophil precursors and (2) the secondary granules in eosinophil granulocytes. It is suggested that the granule-associated RNA molecules may be concerned with the synthesis of at least some of the new protein molecules which were incorporated into the limiting membrane or substance of eosinophil granules long after the immature primary granule stage. Studies of eosinophil precursors which had been incubated with [3H]thymidine for I h showed that the eosinophil granules do not label with this DNA precursor.

Autoradiography↗
PubMed1978

Capacity of ringed sideroblasts to synthesize nucleic acids and protein in patients with primary acquired sideroblastic anaemia.

Bone marrow cells from two patients with primary acquired sideroblastic anaemia were studied using the technique of electron microscope autoradiography. Whereas a significant proportion of erythroblasts containing small to moderate quantities of intramitochondrial deposits incorporated [3H]thymidine into DNA, the majority of cells containing large quantities of intramitochondrial deposits did not. These results are consistent with the idea that several of the early polychromatic cells with large quantities of deposits become arrested in their progress through the cell cycle. The data also revealed that the accumulation of increasing quantities of iron-containing material within the mitochondria of an erythroblast was frequently (but not invariably) associated with and was possibly responsible for (I) a depression of RNA synthesis and (2) a more marked depression of protein synthesis. A small proportion of the erythroblasts showing a depression of protein synthesis also displayed various non-specific ultrastructural abnormalities indicative of cellular injury such as the presence of intranuclear clefts, nuclear membrane-associated myelin figures and lipid-laden intracytoplasmic vacuoles.

Aged↗
PubMed1978

Some features of bone marrow macrophages in patients with homozygous beta-thalassaemia.

The bone marrow macrophages of patients with homozygous beta-thalassaemia were frequently situated adjacent to collagen fibres and sometimes formed intrasinusoidal cytoplasmic protrusions. They also appeared to phagocytose processes of erythroblast cytoplasm (at times containing precipitated alpha-chains) which projected into them from neighbouring erythroblasts. The cytoplasm of the macrophages included large numbers of heavily-iron-loaded secondary lysosomes of various sizes and shapes in addition to phagocytosed erythroblasts, erythrocytes and extruded erythroblast nuclei. Numerous ferritin molecules were found in the cytoplasmic matrix but there were hardly any in the mitochondria, endoplasmic reticulum or golgi saccules. A small number of ferritin molecules were present within the nucleus. Electron microscope autoradiographs of marrow fragments which had been incubated with [3H]leucine for 1 h revealed the presence of newly-synthesized protein molecules in all types of secondary lysosomes. Light microscope autoradiographs showed the [3H]thymidine labelling index of the bone marrow macrophages was less than 1% and suggested that only a very small proportion of these cells were actively preparing for division.

Bone Marrow↗
PubMed1978

Electron microscope autoradiographic studies of the erythroblasts of a case of congenital dyserythropoietic anaemia, type II.

The bone marrow cells of a patient with congenital dyserythropoietic anaemia, type II, were incubated with 3H-thymidine, 3H-uridine or 3H-leucine for 1 h and studied using the technique of electron microscope autoradiography. Several of the erythroblasts which either displayed the characteristic subsurface double membranes or showed various non-specific abnormalities of the nuclear membrane were found to be actively engaged in DNA, RNA and protein synthesis. Both members of some pairs of erythroblasts which were joined together by a spindle bridge were found to be engaged in DNA synthesis, indicating that some spindle bridges persist for a period longer than the duration of the G1 phase. A small proportion of mononucleate and binucleate late (non-dividing) erythroblasts showed a marked depression or arrest of protein synthesis and some or all of such cells were presumably destined to be phagocytosed by the bone marrow macrophages.

Anemia↗
PubMed1978

Strain related infectivity of Neisseria gonorrhoeae for the guinea-pig subcutaneous chamber and the variability of the immune resistance in different breeds of guinea-pig.

The ability of gonococci to infect the subcutaneous chamber in guinea-pigs is strictly strain related. This ability was usually present in prototrophic strains and auxotrophs requiring proline only which were obtained from patients with uncomplicated gonorrhoea, but it was invariably absent in Neisseria gonorrhoeae auxotypes requiring arginine, uracil, and hypoxanthine, or arginine only for growth. All the strains obtained from disseminated gonococcal infections (all dependent upon arginine, uracil, and hypoxanthine) were unable to infect the guinea-pig chamber. Hence, the high invasiveness of N. gonorrhoeae for man and its infectivity for guinea-pig chambers appear to be unrelated properties. Although guinea-pigs of the same origin (Dunkin-Hartley) were used throughout, the degree of immune resistance was found to differ between the lines supplied by various breeders--that is, after a standard immunisation schedule using whole cell gonococcal vaccines, the homologous immune resistance to challenge varied from weak or non-existent in some lines, to highly resistant in others.

Animals↗
PubMed1975

Glenohumeral joint replacement and postoperative rehabilitation.

Prosthetic replacement of the humeral head in patients with severe fractures that detach or crush the articular surface and in patients with glenohumeral arthritis has been done at the Columbia-Presbyterian Medical Center since 1953. Recently, a revised prosthesis for the articular surface of the head of the humerus has been used in combination with a polyethylene glenoid component. This method of total shoulder replacement has been used in patients with rheumatoid arthritis and in other conditions where the glenoid fossa is abnormal. Postoperative physical therapy management is especially important in this unique joint and is explained in detail.

Arthroplasty↗