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Biomedical subjects

S R McCann

Publications and source records attributed to S R McCann.

125 records · Page 7Linked to original sources

Ichthyosis and marrow involvement in malignant histiocytosis of the intestine.

It has recently been suggested that a number of small bowel lymphomas arise from histiocytic cells in the intestine. This has been referred to as malignant histiocytosis of the intestine (MHI) (Isaacson et al, 1979). Three such patients with small bowel malabsorption had the following features: subtotal villous atrophy of the jejunum, generalized ichthyosis, fever and lymphopenia are described. In all three, the bone marrow appearances were similar to those seen in histiocytic medullary reticulosis (HMR) (Scott & Robb-Smith, 1939). A tumour was present in the small bowel and/or mesentery of all patients and the histological lesion was similar to that described as MHI. Two patients had a response to combination chemotherapy. One patient had a complete remission of his disease but this relapsed after 1 year and proved refractory to chemotherapy. A second patient died following chemotherapy with gastro-intestinal perforation and septicaemia and the third patient died shortly after diagnosis and before chemotherapy could be commenced. It is suggested that the combination of signs, symptoms and pathological features described may reflect a specific clinical entity which has not previously been described.

Adult↗

Congenital dyserythropoietic anaemia type II (HEMPAS): a family study.

A family having two affected siblings with congenital dyserythropoietic anaemia type II (HEMPAS) is described. The proband was diagnosed after referral for investigation of haemolytic anaemia. Clinical evaluation and in vivo red cell (RBC) survival and the sequestration studies in the proband indicated that the anaemia was due to a combination of ineffective erythropoiesis and premature destruction of RBCs in the spleen. Scanning electron microscopic examination of peripheral RBCs was undertaken and is reported. The polypeptide composition of RBC membranes was also examined using polyacrylamide gel electrophoresis after solubilisation in sodium dodecyl sulphate. These results are also reported.

Anemia, Dyserythropoietic, Congenital↗

G6PD (Dublin): chronic non-spherocytic haemolytic anaemia resulting from glucose-6-phosphate dehydrogenase deficiency in an Irish kindred.

A new variant of G6PD associated with chronic non-spherocytic haemolytic anaemia (CNSHA) in an Irish male is described. This variant is unique in that it has a normal electrophoretic mobility, Michaelis constant for G6P and NADP, and a normal pH optimum, together with a marked increase in utilisation of the substrate 2 deoxy glucose-6-phosphate. It is also relatively heat stable when compared with the normal (B) variant. These characteristics distinguish this variant from previously reported variants associated with CNSHA and we have called it G6PD Dublin.

Adult↗

Successful pregnancy during combination chemotherapy for Hodgkin's disease.

Hodgkin's disease commonly presents in young adults and can be cured or brought into prolonged remission by radiotherapy, chemotherapy or a combination of both. An increasing number of women are therefore liable to become pregnant during or following treatment for the disease. We describe a patient in whom pregnancy was successful in spite of treatment with chemotherapy during the latter half of the antenatal period.

Adult↗

Acute myeloid leukaemia occurring in untreated chronic lymphatic leukaemia.

A case of acute myeloid leukaemia (AML) occurring in a patient with untreated chronic lymphatic leukaemia (CLL) is presented. The diagnosis of two simultaneous leukaemic processes is based on morphological, cytochemical and immunological findings. The significance of the development of AML in patients with CLL is discussed.

Aged↗

Intracellular lambda light chain inclusions in chronic lymphocytic leukaemia.

A case of chronic lymphocytic leukaemia (CLL) with intracytoplasmic crystalline inclusions in peripheral blood lymphocytes is presented. The inclusions were identified as crystals of lambda (lambda) light chain and were present in bone marrow derived (B-cells) lymphocytes. The occurrence of light chain crystals in CLL may reflect a more primitive defect in immunoglobulin (Ig) synthesis, intracellular transport or secretion than has previously been reported.

Aged↗

Increased membrane binding of erythrocyte catalase in hereditary spherocytosis and in metabolically stressed normal cells.

Normal red blood cell (RBC) membranes were compared with (1) RBC membranes from six patients with hereditary spherocytosis (HS), (2) normal membranes after hemolysis of the RBC in the presence of calcium, or (3) normal membranes after incubation of RBC for 24 hr in phosphate-buffered saline containing calcium without added glucose. When compared with normal controls, polyacrylamide gel electrophoresis with sodium dodecyl sulfate (PAGE SDS) of all three preparations showed an increase in membrane binding of globin and protein band 4.5 (60,000 molecular weight). In an attempt to identify band 4.5, 14 enzymes were assayed in the RBC membranes. Of these, catalase and lactate dehydrogenase were increased in membranes from HS RBC and from normal cells exposed to calcium. Only catalase, however, was present in sufficient quantity and had the correct subunit molecular weight on PAGE SDS and calcium-dependent membrane binding to account for an appreciable portion of 4.5. Caralase was further identified with a component of band 4.5 by double immunodiffusion using a specific anti-catalase antibody.

Calcium↗

IgM pyroglobulinemia with erythrocytosis presenting as hyperviscosity syndrome. I. Clinical features and viscometric studies.

The hyperviscosity syndrome is described in a patient with erythrocytosis and an immunoglobulin M with kappa light chain (IgMK) macroglobulinemia. Viscometric studies were carried out on whole blood and demonstrated the contribution of both the increased hematocrit value and the macroglobulinemia to the whole blood viscosity. Clinical improvement followed phlebotomy and was accompanied by a decrease in whole blood viscosity. Continued treatment with chlorambucil has been associated with a long symptom-free period. The macroglobulin was characterized as a monoclonal IgMK pyroglobulin which retained its thermoprecipitability was reduced to 7S monomers. The presence of IgMK aggregates in the serum may have contributed to the increase in blood viscosity.

Aged↗

IgM pyroglobulinemia with erythrocytosis presenting as hyperviscosity syndrome. II. Biochemical properties and mechanisms of pyrogel formation.

An immunoglobulin M with kappa light chains (IgMK) pyroglobulin from a patient with hyperviscosity syndrome, erythrocytosis and coagulation defects has been studied for its immunochemical properties. At physiologic temperatures the purified macropyroglobulin showed a striking tendency to aggregate in the pentamer as well as in the monomer form. This property was also observed in its H chains. Aggregate formation of the pentamers may have contributed to the blood viscosity and coagulation defects. Formation of pyrogel at 56degreesC was observed with pentamers as well as monomers, but not with separated H or L chains. Amino acid analysis showed quantitative abnormalities of aspartic acid, glycine, cystine and leucine within the H chains. Solubility of the pyrogel in sodium dodecyl sulfate, the pyroglobulin's tendency to aggregate and the cystine deficit of H chains implicate conformational changes leading to hydrophobic bonding at 56degreesC in the formation of pyrogel.

Amino Acids↗

Study of a kindred with hereditary spherocytosis and glyceraldehyde-3-phosphate dehydrogenase deficiency.

A patient with hereditary spherocytosis (HS) was found to have glyceraldehyde-3-phosphate dehydrogenase (G3PD) deficiency by electrophoresis of the isolated red cell membranes on polyacrylamide gels with sodium dodecyl sulfate (PAGE SDS) as demonstrated by a diminished band 6 (G3PD) and confirmed by specific enzyme assay. Thirteen members of his family were studied: four were normal, two had HS alone, three had G3PD deficiency alone, and four had both HS and G3PD deficiency. G3PD deficient kindred members were probably heterozygous, since their red cell enzyme, while qualitatively normal, was present in half normal amounts. The G3PD deficiency alone was asymptomatic, and there was no evidence that the combination of HS with G3PD deficiency increased the clinical severity of the disease. However, G3PD deficiency, when combined with HS, was associated with an increase in protein band 4.5 on PAGE SDS. This band was also increased by incubation of normal red cells without glucose, and appeared to be a protein absorbed to the membrane as a consequence of metabolic stress. Hence, red cells with the combined abnormalities of both HS and G3PD deficiency showed signs of the exceptional metabolic stress to which they were exposed.

Adult↗

Spinal cord disease in hereditary spherocytosis: report of two cases with a hypothesized common mechanism for neurologic and red cell abnormalities.

Two unrelated patients with hereditary spherocytosis developed idiopathic spinal cord dysfunction. This coincidence, combined with similar individual case reports in the older European literature, suggests that abnormalities may exist in constituents common to red cell membranes and nerve tissue. A similar conclusion has been proposed to explain red cell membrane abnormalities in some of the muscular dystrophies.

Aged↗

Autologous stem cell transplantation in myeloma: the St James's Hospital experience, 1997-2003.

BACKGROUND: High-dose treatment with autologous stem cell transplantation (ASCT) has become the standard of care for patients with myeloma below the age of 65 years. AIMS: We report an audit of 60 patients (median age: 52.5 years) who underwent ASCT in the National Bone Marrow Transplant centre in St James's Hospital in Dublin between 1997 and 2003 inclusive. METHODS: Clinical and laboratory data were retrieved from patient medical records and hospital information management systems. RESULTS: Thirty-six patients had IgG, 11 IgA, 1 IgD, 9 light chain and 3 non-secretory MM. Fifty-seven (95%) patients received anthracycline-corticosteroid combination chemotherapy prior to autografting. There was no transplant-related mortality (TRM). Complete (CR) and Partial Responses (PR) were seen in 16 (29.6%) and 29 (53.7%) of those evaluable (n = 54 (90%)). The actuarial Progression-Free (PFS) and Overall Survival (OS) rates at five years are 13% and 55% respectively. CONCLUSION: Centre outcome is comparable to published international series and supports the use of ASCT in the treatment of this malignancy.

Aged↗

Bacteraemia in neutropenic patients.

Empirical antibiotic therapy in febrile neutropenic patients should reflect local patterns of microbial isolates and antibiotic resistance. The aim of this study was to review blood culture isolates and antibiotic resistance from neutropenic cancer patients over a four year period as a guide to empiric antimicrobial therapy. All positive blood culture isolates from a mixed haematology/oncology unit between 1988 and 1991 were evaluated retrospectively. Episodes of bacteraemia rose from 9% in 1988 to 13.7% in 1991. Gram-positive organisms accounted for between 61.3% and 72.7% in each of the four years. Isolates of Gram-negative organisms were between 23.6% and 31.5% of which a significant proportion are due to a heterogeneous group of hydrophilic, non-fermentative organisms. Fungal blood culture isolates accounted for between 3% and 4% each year. All Gram positive isolates were sensitive to vancomycin. Piperacillin was the least active B-lactam antibiotic and tobramycin the least active aminoglycoside reflecting the widespread usage of these agents in the unit. In conclusion, bacteraemic episodes are increasing in this patient population and are mainly due to Gram-positive organisms probably as a result of the extensive use of surgically implanted venous access devices.

Anti-Bacterial Agents↗