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Biomedical subjects

A May

Publications and source records attributed to A May.

At least 253 records · Page 14Linked to original sources

Peritonitis and abdominal free air due to intraperitoneal bladder perforation associated with indwelling urethral catheter drainage.

Perforation of the bladder related to long-term indwelling Foley catheter drainage is a rare and serious complication. We report 2 cases of bladder perforation leading to generalized peritonitis and free intraperitoneal air. These cases re-emphasize the importance of considering bladder perforation in the differential diagnosis of the acute abdomen and of performing a complete abdominal exploration when the site of perforation is not easily detectable.

Abdomen↗

Separation of malignant plasma cells from the bone marrow of patients with myelomatosis.

Complement-mediated lysis of bone marrow cells from patients with myelomatosis using a rabbit antiserum raised against normal peripheral blood mononuclear cells was found to greatly enrich the abnormal plasma cells. Cellular morphology was good and the cells were able to synthesize and secrete paraprotein. This was found to be a quick and useful method of preparing myeloma plasma cells for further studies of their metabolic properties.

Bone Marrow↗

Globin chain synthesis ratios in sideroblastic anaemia.

Globin synthesis ratios were measured on reticulocytes from nine patients with primary acquired sideroblastic anaemia (SA), four patients with hereditary or congenital SA, two patients with secondary acquired SA and three patients with iron deficiency (ID). Ten of the samples from patients with SA and all the samples from patients with ID had normal ratios. Samples from three patients had significantly abnormal ratios, one from a patient with SA and acquired Hb H disease (alpha/beta 0 X 26), one from a patient with secondary acquired SA (alpha/beta 0 X 88), and one from a patient who went on to develop acute myeloblastic leukaemia (alpha/beta 1 X 36). Globin synthesis was stimulated by 100 microM haem similarly in normal, SA and ID reticulocytes. Any limitation of globin synthesis in SA and ID is therefore not easily reversible by adding haem. Inhibition of haem synthesis in nonsideroblastic reticulocytes using 4 mM isonicotinic acid hydrazide for 1 h incubation affected neither total globin synthesis nor the alpha/beta ratio. These results contradict the view that decreased haem synthesis decreases globin chain synthesis and decreases the alpha/beta globin chain synthesis ratios in human reticulocytes. Previously reported findings that haem could reverse globin chain synthesis inhibition in SA were good evidence for a primary deficiency of haem synthesis in the erythroblasts of these patients. Our inability to substantiate these findings emphasizes the need for a re-evaluation of the aetiology of sideroblastic anaemia.

Anemia, Sideroblastic↗

Enrichment of erythroblasts from human bone marrow using complement-mediated lysis: measurement of ferritin.

Sequential lysis of human bone marrow cells with a monoclonal antibody directed against myeloid cells (TG1) and a rabbit antiserum raised against peripheral blood mononuclear cells gave preparations in which 78-97% of the nucleated cells were erythroid, with a 24-77% recovery. Viability was high, morphology was good and the cells were able to divide and differentiate in culture. No metabolic experiments were carried out but the ferritin content of the erythroblasts was measured in four experiments and found to be about 200-2000 times higher than that found in normal erythrocytes. The H/S ratio was high in both erythroblasts and erythrocytes. Fractionation on the basis of density of two erythroblast preparations, one from a patient with sideroblastic anaemia and one from a patient with megaloblastic anaemia, showed that the most immature erythroblasts contained the highest content of ferritin and that this fell with maturation. The H/S ratio stayed the same or fell with maturation. It was concluded that this method would be valuable for the study of the role of erythroblast ferritin in normal and pathological situations.

Anemia, Megaloblastic↗

[Isolated ethmoid meningioma. Apropos of a case].

A case of meningioma confined to the ethmoid region is reported. After emphasizing the rare nature of these primary localizations, and their clinical latency, a brief summary is given of the embryologic origin of these tumors. Comparison of the long-term course of double-sac meningiomas and those developing primarily in the ethmoid region showed improved prognosis for the latter, following total surgical excision, the former having a very marked tendency to recur.

Adult↗

A two-step procedure for obtaining normal peripheral blood T-lymphocytes using continuous equilibrium density gradient centrifugation on percoll.

Equilibrium centrifugation of either peripheral blood mononuclear cells or of pure lymphocytes (obtained by carbonyl iron or glass bead adherence removal of monocytes) on a continuous density gradient of Percoll yielded lymphocyte fractions containing between 92 and 99% T lymphocytes as shown by sheep red blood cell rosetting. B lymphocytes with surface immunoglobulin were found in the regions of low density (1.03-1.065 g/ml) and T lymphocytes in the regions of higher density (1.06-1.08 g/ml). TM lymphocytes with their characteristic positive 'dot' pattern of staining for non-specific esterase were also found mainly in regions of high density. It was concluded that Percoll continuous equilibrium density gradient centrifugation can be used to obtain T lymphocytes in high yield, with high viability and without metabolic changes which may occur after contact with sheep red blood cells. The esterase staining suggested that there was also some separation of T lymphocyte subsets.

Cell Separation↗

Anaemia in patients with myelomatosis.

Twenty-four untreated patients with myelomatosis were studied in order to characterize their anaemia, using standard haematological and ferrokinetic techniques, together with measurements of circulating erythropoietin, erythropoietin sensitivity of marrow cultures and in vitro measurements of haem synthesis. There is a reduction in total erythroid output by the marrow, together with a minor degree of plasma expansion. In patients with normal renal function there is an appropriate increase in erythropoietin in response to anaemia, but in a few cases there may be reduced response of CFU-E to the hormone in vitro. No abnormality of iron status or haem synthesis was found. One case of folate deficiency was discovered.

Adult↗

Erythroblast iron metabolism in sideroblastic marrows.

The uptake of iron by bone marrow erythroblasts and its intracellular distribution have been studied in 23 patients with primary sideroblastic anaemia (SA), five patients with secondary SA and one patient with only non-ringed sideroblasts. EM of erythroblasts from 18 cases showed both mitochondrial iron deposits and cytoplasmic ferritin aggregates in all cases except the patient with only non-ringed sideroblasts. Iron uptake by erythroblasts in whole bone marrow was normal but there was a decreased incorporation into haem and an increased incorporation into cell stroma. Age matching of erythroblasts using Percoll density gradient centrifugation indicated that stromal iron incorporation was high at all stages of erythroblast development even before haem synthesis had become a major metabolic activity and in intermediate and late erythroblasts a real decrease in haem synthesis appeared less certain. These observations, together with the inability to correct the abnormality in vitro with either pyridoxal phosphate or delta amino-laevulinic acid suggest that the primary defect in SA may be an abnormality of mitochondrial iron metabolism rather than an abnormality of haem synthesis.

Adult↗

Spontaneous bacterial peritonitis presenting as a perforated viscus.

A young man with severe nephrotic syndrome and symptoms suggestive of peptic ulcer disease treated with steroids developed symptoms and signs of peritonitis and pneumoperitoneum. Laparotomy and ascitis fluid culture revealed B. fragilis peritonitis without any perforation, suggesting a diagnosis of spontaneous primary peritonitis.

Adult↗

Transferrin-bipyridine iron transfer mediated by haemoproteins.

Rabbit reticulocyte cytosol was able to mediate transferrin-bipyridine iron transfer in the presence of ATP. The cytoplasmic factor responsible for the mediation of iron transfer was identified as haemoglobin. Other cytoplasmic proteins and the membrane fraction were ineffective. Human alpha and beta subunits and human myoglobin were over three times more effective than human haemoglobin A. Carbon monoxide strongly inhibited the mediation of iron transfer. Oxidation of haemoglobin abolished it but methaemoglobin could be reactivated with NADH, even when azide was bound to the haem iron. Neither globin nor haem alone were able to mediate iron transfer, even when NADH was present. Together, the reconstituted methaemoglobin A could be reactivated wtih NADH. Although the physiological significance of this pehnomenon is not clear, the involvement of haemoproteins in intracellular iron metabolism seems likely.

2,2'-Dipyridyl↗