Search PubMed⌕ Search

Biomedical subjects

J Pritchard

Publications and source records attributed to J Pritchard.

At least 235 records · Page 13Linked to original sources
PubMed1983

Allogeneic bone-marrow transplantation in infantile malignant osteopetrosis.

Two infants with malignant osteopetrosis were treated by allogeneic bone-marrow transplantation after marrow ablation with busulphan and cyclophosphamide. Engraftment without graft-vs-host disease occurred in both cases. The first child established stable chimerism and is clinically well 30 months after receiving a histocompatible sibling bone-marrow graft: haematological, radiological, and biochemical features of osteopetrosis have completely resolved. The second child was non-identical with the marrow donor (his older sister) at a single HLA-B locus and received cyclosporin A as prophylaxis for graft-vs-host disease. 11 months after transplantation haematological abnormalities have resolved and radiological features have improved. The findings indicate that allogeneic bone-marrow transplantation should be considered the treatment of choice for infants with severe osteopetrosis who have histocompatible siblings.

Blood Grouping and Crossmatching↗
PubMed1983

Use of panels of monoclonal antibodies in the differential diagnosis of neuroblastoma and lymphoblastic disorders.

Panels of monoclonal antibodies offer a rapid and accurate adjunct to conventional techniques in the diagnosis of neuroblastoma, leukaemia, and lymphoblastic lymphoma. Heterogeneity of antigen expression is observed within a tumour type, and therefore a panel of reagents should be used for each malignancy investigated. Eight monoclonal antibodies which bind to neuroblastoma but not to normal bone marrow and five which bind to leukaemic and lymphoma cells but not to neuroblastoma have been selected for indirect-immunofluorescence testing of bone-marrow aspirates, frozen sections of tumours, and cells from malignant effusions. With this technique a confident diagnosis can be made within 2 h. Profiles of antibodies binding to tumour cells have been used to establish a definitive diagnosis in cases where conventional techniques have proved inadequate.

Adrenal Gland Neoplasms↗
PubMed1983

Pharmacokinetics of melphalan in children following high-dose intravenous injection.

The pharmacokinetics of high-dose IV melphalan (140 or 220 mg m-2) were studied after 12 administrations in 10 children (aged 2.5-16 years) undergoing chemotherapy for either neuroblastoma or Ewing's tumour. To assess whether a simpler and less expensive nitrobenzylpyridine (NBP) spectrophotometric assay for alkylating activity was a satisfactory alternative to high-pressure liquid chromatography (HPLC), the plasma melphalan concentration was estimated by both methods in five cases. Analysis of the disposition of melphalan gave a mean half-life of 1.3 +/- 1.0 (SD) h, clearance 18.4 +/- 9.4 l X h-1 X m-2, and apparent volume of distribution 26.3 +/- 18.0 l X m-2. These pharmacokinetic parameters were similar to those found in adults: no correlation was found between any parameter and age or glomerular filtration rate. NBP alkylating activity determinations yielded consistent results and good correlation with plasma melphalan concentration. However, concordance analysis indicated a consistent bias, the NBP assay always giving lower estimates of plasma melphalan concentration: HPLC assay therefore remains the method of choice for determining plasma melphalan pharmacokinetics.

Adolescent↗
PubMed1983

Detection of bone marrow invasion by neuroblastoma is improved by sampling at two sites with both aspirates and trephine biopsies.

Two hundred and eight serial bone marrow samples from 49 consecutively diagnosed children with neuroblastoma were studied retrospectively for evidence of tumour invasion. Bone marrow involvement was found in 24 patients at diagnosis and in four more at a later stage in their disease. Trephine biopsies were more effective than aspirates for tumour detection in 20% of the 154 paired aspirate/trephine procedures, whilst the reverse was the case in 7%. Imprints of trephines gave no additional information. Bilateral sampling (aspirates and trephines) improved the tumour detection rate by 10% over that attained by sampling a single site. There was some correlation between specific appearances in aspirate and in trephine samples, for example the hypocellular smear and the trephine biopsy showing much stromal reaction to tumour infiltration. Bilateral iliac crest bone marrow aspirates and trephine biopsies are indicated in children with neuroblastoma, both for initial staging and for monitoring of progress.

Biopsy↗
PubMed1982

The effects of radiation therapy for Hodgkin's disease in a child with ataxia telangiectasia: a clinical, biological and pathologic study.

Stage I lymphocyte-predominant Hodgkin's disease was diagnosed in a 44-month-old girl. Although immune deficiency was suspected and IgA deficiency demonstrated, the diagnosis of an ataxia-telangiectasia (AT)-like syndrome was not confirmed until eight weeks later when results of studies on the radiosensitivity of cultured skin fibroblasts were available. The child had none of the usual physical stigmata of AT. Severe acute radiation damage followed the treatment of this child with standard doses of radiation therapy. Clinical, pathologic, and radiobiologic correlations are drawn. The diagnosis of a malignant lymphoma disorder in children under the age of five should alert clinicians to the possibility of immune deficiency and, even in the absence of classical physical signs, to AT in particular. Suggestions for the management of future similar cases are put forward.

Ataxia Telangiectasia↗
PubMed1982

Alpha feta (alpha FP) monitoring of response to adriamycin in hepatoblastoma.

While emphasizing the potential of chemotherapy (particularly adriamycin) in the treatment of hepatoblastoma, Andrassy et al., omit mention of the importance of serial serum alpha FP measurements in determining response and in early detection of recurrence. Serum alpha FP was elevated (range 5,000-1,800,000 micrograms/l) in 10 of 11 children with hepatoblastoma seen at our hospital between 1970 and 1980 and is, as others have emphasized, a potentially useful "marker" for this tumor. We report here the details of one patient in whom alpha FP monitoring was crucial to early detection of pulmonary metastases; complete response to adriamycin was subsequently documented.

Carcinoma, Hepatocellular↗
PubMed1982

High-dose melphalan with autologous marrow for treatment of advanced neuroblastoma.

A group of 12 children with advanced neuroblastoma (7 Stage IV and 5 Stage III), selected by their initial response to chemotherapy with pulsed cyclophosphamide/vincristine/Adriamycin (CVA), were given consolidation therapy with high-dose melphalan (140 mg/m2) and then surgical removal of residual disease. Twenty-two high-dose melphalan procedures were combined with autologous marrow grafting to offset myelotoxicity and were well tolerated. In each of 2 additional children, procedures carried out without marrow autografting led to serious marrow and mucosal toxicity. There were no treatment-related deaths. In 7/11 patients with evaluable computerized tomographic (CT) scans there was a decrease in maximum diameter of the primary tumour after melphalan. Complete response was achieved in 6 patients, of whom 3 are well and have no evidence of disease at 35, 33 and 18 months from completion of all treatment; however, although survival (median 23 months) of all 12 autografted patients is longer than that of 28 comparable children treated between 1970-77 with conventional chemotherapy (median 14 months) the difference is not statistically significant. High-dose melphalan is a safe and tolerable treatment in children when combined with autologous marrow grafting, but further study is required to determine whether the procedure can improve prognosis for patients with advanced neuroblastoma.

Adolescent↗
PubMed1982

A biochemical and immunohistological study of collagen synthesis in Ewing's tumour.

The synthesis and localization of collagen have been studied on material from a total of 16 primary Ewing's tumours. The predominant collagen extracted from the tissues and synthesized in short-term cultures was type I. The proportion of type III collagen was relatively small and variable (0-8%) in the direct tumour extracts, but a higher proportion (29-38% of the total collagens) was synthesized in culture. Immunofluorescence studies showed that positive staining for all types of collagen tested (types I, III, IV and V) was restricted to stroma; there was no evidence of collagen either within the tumour cells or in their pericellular matrix, a finding endorsed by negative staining for reticulin in the same areas. The absence of any evidence for type IV or V collagen synthesis by Ewing's cells argues against an endothelial origin for the tumour, and indicates that collagen analysis is unlikely to be of value in the diagnosis of this particular sarcoma.

Bone Neoplasms↗
PubMed1982

Stage II neuroblastoma. Adverse prognostic significance of lymph node involvement.

Thirty-three children aged between 1 month and 16 years (median 1 year, 7 months), were treated for stage II neuroblastoma with surgery, radiotherapy, or chemotherapy, alone or in combination. After 3 years 70% were living, 6 children had died from the disease, and 4 had died as a result of treatment. Patient characteristics (age, gender) and tumour characteristics primary site, presence of lymph node involvement, catecholamine excretion, histology) were reviewed in an attempt to determine prognostic features. While age under 1 year at diagnosis was, as expected, favourable in this series, the most important prognostic variable was the presence or absence of regional lymph node involvement. No patient with uninvolved nodes died of neuroblastoma and the difference in the 3-year survival rate between these patients and those with positive nodes was statistically significant. Although this study of patients treated between 1970 and 1977 provided no clear evidence that either postoperative radiotherapy or contemporary chemotherapy was of benefit, our findings suggest that subclassification of stage II patients into 'node-positive' and 'node-negative' groups will help to define those who might benefit from improved adjuvant postsurgical treatment.

Adolescent↗
PubMed1982

Combined immunological and histochemical analysis of skin and lymph node lesions in histiocytosis X.

The immunological phenotype of the cells involved in skin and lymph node lesions from two cases of histiocytosis X (H-X) were analysed by immunofluorescence techniques using combinations of heterologous and monoclonal antisera to Ia-like antigen and human cortical thymocyte (HTA-1) determinant. These cells were also characterised by a new technique using simultaneous immunofluorescence and enzyme histochemistry for acid phosphatase (ACPase). The major cell type in the lesions was found to express the same Ia+, HTA-1+ phenotype as normal epidermal Langerhans' cells (LC) and was unreactive for ACPase. Additional cell types included Ia-, HTA-1- multinucleate giant cells and residual lymphoid populations. These findings endorse previous concepts that H-X is a proliferation of abnormal LC and emphasise the heterogeneous nature of the cells involved in the disease.

Acid Phosphatase↗
PubMed1981

Monoclonal antibody to ganglioside GQ discriminates between haemopoietic cells and infiltrating neuroblastoma tumour cells in bone marrow.

An immunological approach has been sought for the identification of minimal metastatic spread of neuroblastoma to bone marrow. Here we describe the reactivity of the monoclonal antibody A2B5 to human neuroblastoma cell lines and fresh tumour tissue. This reagent, raised against chick retinal cells, reacts with all human neuroblastoma lines assayed although quantitative differences in antigenic expression exist between cultures. Analysis of tumour cells in heavily infiltrated bone marrow aspirates indicates that only 70% of the samples reacted with A2B5, suggesting that the heterogeneity seen in the expression of antigen on cell lines is paralleled in fresh tumour material. A2B5 showed no reactivity to either a panel of human leukaemic cell lines or normal human bone marrow, although reactivity to an occasional leukaemic marrow aspirate was detected. We suggest that A2B5 could form part of a panel of monoclonal reagents necessary for detecting metastatic spread of all neuroblastoma cells to bone marrow. Such a group of reagents may be useful therapeutically in a programmed of autologous bone marrow transplantation for the removal of tumour cells prior to reinfusion of haemopoietic cells to patients receiving high-dose chemotherapy.

Antibodies, Monoclonal↗
PubMed1981

Plasma vasoactive intestinal polypeptide and other regulatory peptides in children with neurogenic tumours.

Plasma regulatory peptide levels were studied in a group of 21 children with neurogenic tumours and in 22 control children. Plasma vasoactive intestinal polypeptide (VIP) levels were significantly higher in children with neurogenic tumours than in normal children or those with other tumours (p less than 0.05). There was no significant difference between the groups in plasma levels of gastrin, pancreatic glucagon or pancreatic polypeptide. The plasma VIP level may thus be a helpful diagnostic marker for neurogenic tumours in children.

Adolescent↗
PubMed1981

Intractable diarrhoea in a patient with vasoactive intestinal peptide-secreting neuroblastoma. Attempted control by somatostatin.

A 1 1/2 year old child developed profuse watery diarrhoea, shown to be due to excessive plasma vasoactive intestinal peptide (VIP) levels, whilst on treatment for metastatic neuroblastoma. Because it was unresponsive to alternative treatment, an attempt was made to control the diarrhoea with a somatostatin infusion. The attempt failed despite the fact that serum VIP levels were substantially reduced. Possible reasons for failure are discussed and the importance of plasma VIP as a marker for maturation in neuroblastoma emphasised.

Diarrhea↗