Search PubMed⌕ Search

Biomedical subjects

D C Brown

Publications and source records attributed to D C Brown.

At least 109 records · Page 6Linked to original sources
PubMed1989

The prognostic significance of immunophenotype in high-grade non-Hodgkin's lymphoma.

The prognostic value of immunophenotyping lymphomas was assessed by studying 51 cases of high-grade non-Hodgkin's lymphoma for which long term clinical follow-up (14-28 years) was available. Using antibodies which identify T- and B-cell-related antigens in formalin-fixed, paraffin-embedded material, 43 were shown to be of B-cell and eight of T-cell phenotype. In terms of survival, cases of high-grade T-cell lymphoma fared significantly worse (P less than 0.05) than cases of high-grade B-cell subtype. These findings support the belief that T-cell lymphomas have a more aggressive clinical course than their B-cell counterparts.

Antibodies, Monoclonal↗
PubMed1989

Outcome and benefits of upper gastrointestinal endoscopy in the elderly.

Presenting symptoms, physical findings and treatment were reviewed in 70 patients over 65 years old who underwent oesophago-gastro-duodenoscopy in the Royal Victoria Hospital, Belfast, during an 18-month period. Most frequent indications for the procedure were epigastric pain, retrosternal pain or haematemesis. Physical signs were present in only 54%. Abnormal endoscopic findings were detected in 97%. The majority of patients responded to subsequent treatment. It was not possible to identify clinical features associated with major gastrointestinal pathology, which aided selection of those subgroups of elderly patients who would most benefit from endoscopy.

Aged↗
PubMed1989

A retrospective review of the effects of one year of triamcinolone acetonide aerosol treatment on the growth patterns of asthmatic children.

Retrospective growth data were evaluated for 82 asthmatic children (59% dependent on oral corticosteroids) receiving triamcinolone acetonide aerosol for 1 year. Two-thirds of the steroid-dependent patients discontinued oral steroids. Triamcinolone acetonide did not adversely affect height or weight gain, although steroid-dependent asthmatics gained less weight than predicted, probably due to diminished fluid retention and appetite associated with decreased oral steroid doses and resolution of cushingoid features.

Adolescent↗
PubMed1989

Diagnosis of myelomonocytic and macrophage neoplasms in routinely processed tissue biopsies with monoclonal antibody KP1.

A new monoclonal antibody, KP1, against the CD68 antigen, which labels macrophages and other members of the mononuclear phagocyte lineage in routinely processed tissue sections, has been used to stain a range of lymphoid, histiocytic, and myelomonocytic proliferations. All 20 neoplasms of myeloid, myelomonocytic, and presumed macrophage derivation reacted with antibody KP1. None of the 22 cases of T cell neoplasia had positive reactions. Although 14 of 41 B lineage lymphomas and leukaemias were stained by antibody KP1, staining was usually confined to small dots of reactivity, in contrast to the strong and extensive cytoplasmic staining seen in the neoplasms of myeloid and macrophage/monocyte origin. Furthermore, positive B cell neoplasms were almost all small cell proliferations, which are unlikely to be confused with myelomonocytic malignancies. It was concluded that antibody KP1 is a valuable addition to a panel of monoclonal antibodies for phenotyping lymphomas, particularly in routinely fixed tissues. It should assist the pathologist in the recognition of extramedullary presentation of leukaemia, aid in the diagnosis of suspected cases of true histiocytic neoplasia, and allow for quantitation of macrophages infiltrating lymphomas and other solid tumors.

Antibodies, Monoclonal↗
PubMed1989

Immunocytochemical analysis of cytocentrifuged fine needle aspirates. A study based on lung tumors aspirated in vitro.

The value of Cytospin preparations of fine needle aspiration (FNA) biopsy material for immunocytochemical analysis was investigated using aspirates obtained from 23 resected human lung tumors. The results were compared with those on cryostat sections from the same tumors. The Cytospin preparations of the FNA biopsies gave the best immunostaining reactions and enabled a comprehensive range of monoclonal antibodies (MAbs) to be utilized. The quality of the Cytospin immunostaining compared favorably with that on cryostat sections of the same tumors and generally yielded a similar immunophenotype. However, the Cytospin preparations were not suitable for staining with MAb Ki67, which detects an antigen associated with cellular proliferation. With Ki67, conventionally prepared smears were much superior and enabled an assessment of tumor growth fraction that concurred with the growth fraction calculated from cryostat sections in most cases.

Antibodies, Monoclonal↗
PubMed1988

Use of an intraruminal soluble glass bolus containing melatonin for early lamb production.

The use of melatonin to advance the onset of seasonal oestrus is potentially useful for early lamb production. A number of delivery systems for melatonin have been developed and this study evaluates an intraruminal soluble glass bolus under field conditions. Anoestrous, non-lactating mule and Dorset cross mule ewes were treated in late June with two types of bolus of different solubilities (melatonin 1, 'slow release' and melatonin 2, 'extra slow release'). Rams were introduced in mid-August for a target lambing pattern in mid-January. The percentage pregnancy/lambing rates were 80/78, 97/92 and 100/100 in the control, melatonin 1 and melatonin 2 groups, respectively. The number of lambs born per ewe put to the ram was significantly increased by treatment with melatonin 2 (P less than 0.05) from 1.17 to 1.64 in the mule ewes and 1.64 to 1.72 in the Dorset cross mule ewes. The melatonin containing soluble glass bolus is a novel and convenient method of reducing the number of barren ewes in an early lambing flock.

Animals↗
PubMed1988

An investigation into the nature of giant cells in cardiac and skeletal muscle.

In an immunohistochemical study of six cases of giant cell myocarditis, the typical giant cells have been shown to express up to four different macrophage-associated antigens, but not desmin, the intermediate filament protein characteristic of muscle cells. These results support the view that the giant cells have a macrophage rather than a myogenic origin. In contrast, the giant cells found in regenerating skeletal muscle have the immunophenotype of muscle cells and not of macrophages supporting their muscle origin.

Adult↗
PubMed1988

Carcinoma of the cervix uteri: an assessment of tumour proliferation using the monoclonal antibody Ki67.

Thirty-one cervical biopsies of invasive carcinoma have been studied by immunohistochemical means using the monoclonal antibody Ki67 to determine tumour cell proliferation rates. A wide range (10-50%) in the extent of Ki67 staining (expressed as the percentage of labelled tumour cells) was observed indicating considerable variation on tumour growth rates. There was no significant relationship between the percentage of positive cells and conventional histological parameters such as cell type or tumour differentiation. Immunostaining with monoclonal antibody Ki67 therefore provides a new approach to the assessment of cervical tumour biopsies which will require long term clinical follow-up to establish its prognostic significance.

Adenocarcinoma↗
PubMed1988

Ganciclovir pharmacokinetics during renal impairment.

Limited information is available concerning the use of ganciclovir (GCV) in patients with severe renal impairment. The pharmacokinetics of GCV were studied in a heart transplant recipient requiring hemodialysis. The total body clearance was calculated to be approximately 5% of that previously reported for patients with normal renal function. GCV was removed by hemodialysis; a single 4-h procedure decreased the concentration in plasma by approximately 50%. GCV can be safely administered to patients with renal insufficiency if concentrations in plasma are monitored.

Acyclovir↗
PubMed1988

Total pancreatectomy for chronic pancreatitis.

The operation of total pancreatectomy is performed rarely. Its role in the management of patients with chronic pancreatitis remains to be elucidated. We have reviewed our series of 29 total pancreatectomies for benign disease [14 women median age 39 years; 15 men median age 34 years]. Twelve underwent standard total pancreatectomy, in 17 duodenum preserving total pancreatectomy (DPTP) was performed. There was one death (mortality 3.4%). In no patient was the total pancreatectomy the first operative procedure. The patients were compared with age and sex matched diabetic control subjects selected on a best fit basis from the diabetic clinic database. The aetiology of the pancreatitis was idiopathic nine, pancreas divisum nine, alcohol eight and other causes three. The indication for surgery was pain 27, acute pancreatitis one and cholangitis with pancreatitis one. The complications of the procedures were mainly caused by infection [wound three, chest six and central line sepsis four] and in two there was a leak from the duodenum; no patient required re-operation. The postoperative stay [standard total, median 21 days (range 13-98) DPTP median 31 days (range 17-49)] has lengthened over the period due to greater attention to analgesic, diabetic and enzyme deficiency control before discharge. In standard total pancreatectomy there were five major hypoglycaemic episodes with only two in 17 DPTP patients. The per cent ideal body weight, the insulin requirement and the HbAl compared less well in standard total pancreatectomy group compared with controls than did DPTP. With both groups large doses of enzyme replacement were required, and this proved of importance in diabetic control. Our experience with total pancreatectomy suggests that pain will be improved in over 80% of patients and that the results of surgery will improve with prolonged follow up provided attention is given to analgesic abuse, enzyme deficiency and diabetes.

Adult↗
PubMed1988

Interleukin-1 is an astroglial growth factor in the developing brain.

The immunomodulator interleukin-1 (IL-1) is found to be an astroglial growth factor during development of the mammalian brain. In vitro studies indicate that ameboid microglia, a class of brain mononuclear phagocytes, are the likely source of IL-1. Examination of different brain regions during development shows IL-1 production only after the appearance of ameboid microglia. These observations suggest that brain mononuclear phagocytes secrete growth factors that regulate normal growth and development of the CNS.

Animals↗
PubMed1987

Hematuria. When is it cause for alarm?

The urine of less than 3% of healthy persons shows more than three red cells per high-power field, which is about the limit of sensitivity of test strips for occult blood. Even minimal hematuria may herald serious problems and must be investigated. Common causes include infection, urethritis, and urethrotrigonitis (25%); stone (20%); and tumor (15%). Although hematuria may be caused by coagulopathy, patients with anticoagulant-induced hematuria must be examined for anatomic defects. Hematuria may originate from the kidney or the urinary tract; red cell casts and dysmorphic red cells suggest a renal source. Hematuria arising from the kidney is classified as glomerular (eg, various forms of glomerulonephritis) or nonglomerular (eg, polycystic kidney disease, cancer). If the urine is pigmented but test strips are negative, or test strips are negative but no red cells are seen, pseudohematuria must be considered.

Hematuria↗
PubMed1987

Interleukin 1 release by human monocytes treated with liposome-encapsulated lipopolysaccharide.

Liposome therapy offers a unique method of delivering antifungals, antiprotozoans, and macrophage-activating factors directly to reticuloendothelial cells. Although liposomes are entering clinical trials, their effect on Il 1 synthesis and release has yet to be determined. The beneficial, as well as possible pathological, effects of liposome therapy may be due to IL 1 released by reticuloendothelial cells. This study examined the effects of multilamellar phospholipid vesicles on the synthesis and release of IL 1 from human peripheral blood monocytes. Liposomes consisting of phosphatidylcholine and phosphatidylserine in molar ratio of 7:3 did not stimulate IL 1 release, and did not diminish the level of IL 1 release when monocytes were subsequently stimulated with LPS or Staphylococcus aureus. Surprisingly, LPS encapsulated in liposomes failed to stimulate IL 1 release from monocytes. This defect was limited to the release of IL 1, because monocytes stimulated with liposomes containing LPS had control levels of intracellular (cytosolic) and membrane IL 1. By contrast, LPS associated with lyophilized liposomes induced the secretion of IL 1 and behaved similarly to free LPS. These findings indicate that LPS activation of monocytes may involve not only the synthesis of IL 1 but activation of the secretory mechanism for IL 1, and that these two events could be independent, that the density of LPS molecules at the surface of the liposome may influence the degree of monocyte activation as measured by intracellular IL 1 synthesis, membrane accumulation, and secretion into the medium, and that intracellular lipids may not interfere with the secretory mechanism, because liposomes made with phospholipids differing in acyl chain length or the headgroup behaved identically.

Cell Membrane↗
PubMed1987

Subcellular localization of human monocyte interleukin 1: evidence for an inactive precursor molecule and a possible mechanism for IL 1 release.

IL 1 activity, as assayed by the proliferation of responsive mouse thymocytes and a human astrocytoma cell line, was detected on the membrane of 1% paraformaldehyde-fixed activated human monocytes. Resting, unactivated monocytes did not display IL 1 activity. Maximum induction of membrane IL 1 was obtained from monocytes treated with polyclonal activators, such as LPS or Staphylococcus aureus, whereas adherence was a weak inducer of membrane IL 1. Isolated cell compartments as plasma membranes, crude lysosomes, and crude cytosol from activated human monocytes expressed significant IL 1 activity, whereas the endoplasmic reticulum showed no IL 1 activity. Exposure to trypsin of either fixed, activated human monocytes or cell compartments from unfixed monocytes, revealed biologically active IL 1 in the membrane, crude lysosome, and crude cytosol, but not in the endoplasmic reticulum. The IL 1 activity in the purified cytosol, prepared by extraction with digitonin, was considerably increased by the trypsin treatment, whereas the increase in IL 1 activity within crude lysosomes and plasma membranes was less. The cell compartments from nonactivated monocytes did not express active IL 1 and trypsin treatment revealed no active IL 1, suggesting the absence of a pool of the trypsin-sensitive form of IL 1. The data confirm the presence of membrane-bound IL 1 in activated human monocytes and indicate that an inactive precursor molecule can be found in the cytosol of such cells. Furthermore, the absence of IL 1 activity either in its active form or as the inactive precursor in the endoplasmic reticulum suggests that IL 1 is not a conventionally secreted protein. Because IL 1 was found in the cytosol as a precursor and in the lysosomal fractions in an active form, these data suggest that after the synthesis and processing of the cytosolic precursor, the 17-kda IL 1, is released via lysosomal vesicles.

Cell Membrane↗
PubMed1987

Liposomes expressing IL 1 biological activity.

We determined the activity of IL 1, obtained from various human monocyte subcellular compartments, when associated with liposomes. Soluble IL 1, bound to the outer surface of lyophilized liposomes, stimulated responsive target cells. However, this activity was not preserved when soluble IL 1 was incorporated into the inner chambers of classical liposomes. In contrast, monocyte plasma membranes that exhibited IL 1 activity had the same level of activity when presented on lyophilized liposomes and when incorporated inside the classical liposomes. However, monocyte plasma membranes bound to the outer surface of the liposomes exhibited greater activity than the monocyte membrane IL 1 itself in its soluble form. This suggests that membrane IL 1 is an integral membrane protein, readily integrated into the lipid bilayers. Like soluble IL 1, the expression of IL 1 activity present in the cytosol of activated monocytes was decreased by incorporation into liposomes, but was high and active when presented on lyophilized liposomes. The best artificial cell reconstitution was obtained with lyophilized liposomes in association with monocyte cytosol and plasma membranes. When an unactivated monocyte compartment was mixed with one from an activated monocyte, the signal was equal to that of the activated cell compartment alone. The IL 1 activity of activated cell fractions associated with lyophilized liposomes was determined, and an increase of IL 1 activity for both plasma membranes and cytosol was observed, whereas a decrease of the signal was obtained for the lysosomal compartment. Endoplasmic reticulum showed no IL 1 activity, even after trypsin treatment. The highest activity after trypsin treatment was recovered in the cytosol associated with lyophilized liposomes, suggesting that molecules obtained after this treatment were able to bind tightly to the lipid bilayers.

Cell Compartmentation↗