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Biomedical subjects

J Pritchard

Publications and source records attributed to J Pritchard.

At least 91 records · Page 5Linked to original sources
PubMed1998

Multivariate analysis of risk factors in stage 4 neuroblastoma patients over the age of one year treated with megatherapy and stem-cell transplantation: a report from the European Bone Marrow Transplantation Solid Tumor Registry.

PURPOSE: The European Bone Marrow Transplantation (EBMT) Solid Tumor Registry (STR) contains detailed information on children with advanced neuroblastoma who, after standard-dose induction chemotherapy and surgery, received myeloablative megatherapy (MGT) followed by stem-cell transplantation (SCT). This data base was analyzed to identify factors that predict event-free survival (EFS). PATIENTS AND METHODS: Eligibility criteria were stage IV neuroblastoma, age over 1 year at diagnosis, and no relapse before MGT/SCT. Between February 1978 and July 1992, 549 patients were registered by 36 European transplant centers. The median age at diagnosis was 36 months (range, 13 to 216 months) and the male-female ratio was 1:45. Before MGT, 157 patients were in complete remission (CR), 156 in very good partial remission (VGPR), and 208 in partial remission (PR), whereas 24 had had only a minor response (MR). One hundred ten of 546 patients had undergone two successive MGT procedures. The median observation time was 60 months (range, 12 to 187 months). RESULTS: Actuarial EFS is 26% at 5 years. Multivariate analysis by the Cox proportional hazards regression model included 529 patients with complete data sets. After adjustment for treatment duration before MGT and double MGT procedures, two adverse, independent risk factors that influenced EFS were identified: (1) persisting skeletal lesions before MGT as defined by technetium (99TC) scans and/or meta-iodobenzylguanidine (mIBG) scans (P = .004) and (2) persisting bone marrow involvement before MGT (P = .03). CONCLUSION: After induction treatment, persisting skeletal disease as defined above and persisting bone marrow involvement may be predictive of a particularly poor outcome. Physicians may consider this an additional important tool to decide the patient's management.

Adolescent↗
PubMed1998

Plasma adrenal, gonadal, and conjugated steroids before and after long-term overfeeding in identical twins.

An analysis of the data collected in the Quebec Overfeeding Study of identical twins was undertaken to determine any evidence of a genotype effect on plasma levels of adrenal and gonadal steroids arising from long term positive energy balance. Plasma levels of sex hormone-binding globulin (SHBG), testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEA-S), androsterone glucuronide, androstane-3 alpha, 17 beta-diol glucuronide (3 alpha-DIOL-G), and cortisol were measured in 12 pairs of young, sedentary, male monozygotic twins before and after 100 days of overfeeding. The dietary energy excess of 4.2 MJ/day (1000 Cal), 6 days a week, resulted in a total positive energy balance of 353 MJ (84,000 Cal). Overfeeding induced significant changes (P < 0.0001) in body weight and other measures of body composition. Within-twin pair resemblance was observed at baseline in all steroids, except cortisol [intraclass correlation range: DHEA-S, 0.50 (P < 0.05); DHT, 0.77 (P < 0.001)] and was lost with overfeeding, except for DHT and SHBG (P < 0.05). SHBG levels fell and 3 alpha-DIOL-G rose with the gain in body fatness. The change in testosterone was a significant correlate of the change in upper body fat (r = -0.48; P < 0.05). The change in 3 alpha-DIOL-G correlated positively with increases in all measures of central adiposity (r = 0.52; P < 0.01). A decrease in DHEA-S occurred with a higher, but not with a lower, gain in abdominal visceral fat (P < 0.05). Thus, analysis of adrenal and gonadal steroids and of conjugated metabolites before and after overfeeding in monozygous twins supports the idea that there is a genotype effect on steroid circulating steroid levels and that these blood levels are correlated with the pattern of body fat distribution. Moreover, the baseline within-twin pairs similarity in steroid levels was attenuated by prolonged positive energy balance and body fat gain.

Adipose Tissue↗
PubMed1997

Diabetes insipidus associated with Langerhans cell histiocytosis: is it reversible?

Fourteen of 58 (24%) children with Langerhans cell hisiocytosis (LCH) currently attending the Hospital for Sick Children (London) developed thirst and polyuria during the course of their disease. Three had single-system disease confined to bone, and 11 had multisystem disease. The median age at presentation of LCH was 2 years 0 months, and polyuria/polydipsia developed at a median age of 3 years 9 months (range 1 month before diagnosis of LCH to 4 years after diagnosis). Each child had a water deprivation test with measurement of urinary arginine vasopressin (AVP) to document diabetes insipidus. The doses of 1-desamino-8-D arginine vasopressin (DDAVP) required to control symptoms were compared at diagnosis and at a mean follow-up of 7 years 8 months. Local and systemic treatment was recorded. Ten of 14 children were shown to have "complete" diabetes insipidus, whilest the other four had "partial" diabetes insipidus. Seven children were treated with irradiation. with or without systemic chemotherapy, six with systemic chemotherapy only, and one with DDAVP replacement only. No child, including two with partial diabetes insipidus irradiated within 4 weeks of the onset of symptoms, lost symptoms of polyuria/polydypsia and none was able to discontinue DDAVP replacement. One child treated with Etoposide showed a temporary rise in urinary AVP level to within the normal range but still needed DDAVP to control her symptoms. The mean doses of DDAVP at onset of diabetes insipidus and at follow-up were 9.3 micrograms and 18 micrograms daily, respectively. We conclude that the most appropriate treatment for reversing diabetes insipidus complicating Langerhans cell histiocytosis is yet to be determined. Precise documentation of posterior pituitary dysfunction, including measurement of urinary AVP levels, is essential if the effects of new forms of treatment are to be assessed accurately.

Child↗
PubMed1997

Contemporary classification of histiocytic disorders. The WHO Committee On Histiocytic/Reticulum Cell Proliferations. Reclassification Working Group of the Histiocyte Society.

Pathologists and pediatric hematologist/ oncologists of the World Health Organization's Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

Cell Lineage↗
PubMed1997

Markedly improved survival in malignant sacro-coccygeal teratomas--16 years, experience.

AIM OF STUDY: To see the impact of cisplatin- and carboplatin-based protocols on survival in malignant sacrococcygeal teratomas (SCT). METHODS: Twenty infants and children with malignant SCT were treated at the Hospital for Sick Children, Great Ormond Street, London, over a 16-year period from 1979 to 1994. There were 5 males and 15 females, age ranged from 1 day to 3.5 years (mean 18 months). RESULTS: Twelve patients (60%) had distant metastasis: 9 lung metastasis, 2 liver involvement, 2 bony metastases, 1 cerebral metastasis and 1 bilateral inguinal lymph node deposits. From 1982 to 1986, patients received the BEP chemotherapy protocol which included cis-platinum, bleomycin and etoposide (VP 16). After 1986, cis-platinum was replaced with carboplatin in the new JEB protocol. Patient 1 did not receive any chemotherapy, Patients 2-4 received varying protocols (2 deaths), Patients 5-8 received the BEP regime (1 death) and Patients 9-20 received JEB (1 death). The first three deaths were due to uncontrolled local disease and/or metastasis, while the latter death was due to bleomycin toxicity. Overall, 9 of 12 (75%) patients with distant metastasis survived as opposed to 7 of 8 (88%) patients with localised disease. Of the 12 patients who received the JEB protocol, 11 (92%) survived, including 7 patients with metastatic disease and 2 with local recurrence. Seven patients (35%) had relapse while on treatment or follow-up, 4 of these are disease-free with further therapy. In 6 of these children, serum AFP rose before there was clinical or radiological evidence of relapse. In 2 other patients, further chemotherapy was recommenced solely on the basis of rising serum AFP, these patients did not subsequently develop overt metastasis. CONCLUSIONS: We conclude that the treatment of choice for malignant SCT is the JEB regime, to be given for 4 courses or to be continued for 2 courses beyond documented Complete Response (CR). Excision of the primary tumour and coccyx should be done in all cases even if a CR has been documented. Metastases not responding to chemotherapy would need appropriate surgery, radiotherapy is hardly ever needed. An overall cure rate exceeding 90% can be expected.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Malignancies in UK children with HIV infection acquired from mother to child transmission.

By April 1995, 302 cases of vertically acquired HIV infection had been reported through the British Paediatric Association Surveillance Unit. Over 50% of these children had developed an AIDS indicator disease, including nine malignancies (seven cases of non-Hodgkin's lymphoma (NHL) and two of Kaposi's sarcoma). There were two other malignancies that were not AIDS indicator diseases. In children less than 5 years of age the incidence of NHL was approximately 2500 times greater than expected in the UK child population. Three children presented with NHL as their AIDS indicator disease and four developed NHL at a median of 14 (range 10-19) months after the initial diagnosis of AIDS. Six of the seven children died at a median of 6.5 (range 2-14) months after the diagnosis of NHL. The seventh child responded to treatment and is alive nearly four years later. Histology was available in five cases, of which four were of B cell and one of T cell origin. Epstein-Barr virus was detected in all three patients with NHL where it was sought; all had B cell lymphomas. Although comparatively rare, malignancies occur in children infected with HIV and may be the presenting illness. Paediatricians now need to consider HIV infection as a predisposing cause of childhood cancer, especially NHL.

Child, Preschool↗
PubMed1997

Honeydew sugars and osmoregulation in the pea aphid Acyrthosiphon pisum

Pea aphids, Acyrthosiphon pisum, containing their symbiotic bacteria (untreated aphids) and experimentally deprived of their bacteria by treatment with the antibiotic rifampicin (antibiotic-treated aphids) were reared on the plant Vicia faba. The sugars in the honeydew produced by untreated aphids comprised predominantly the monosaccharides glucose and fructose, while the honeydew of antibiotic-treated aphids contained considerable amounts of oligosaccharides of up to 16 hexose units. The honeydew and haemolymph of the aphids were iso-osmotic, and their osmotic pressure was significantly lower in untreated aphids (0.91&shy;0.95 MPa) than in antibiotic-treated aphids (1.01&shy;1.05 MPa) (P<0.05). For insects reared on chemically defined diets containing 0.15&shy;1.0 mol l-1 sucrose (osmotic pressure 1.1&shy;4.0 MPa), the osmotic pressure of the aphid haemolymph did not vary with dietary osmotic pressure, but was regulated to approximately 1.0 MPa in untreated and 1.3 MPa in antibiotic-treated aphids. The sugars in the aphid honeydew varied with dietary sucrose concentration; with monosaccharides dominant at low concentrations and oligosaccharides dominant at high concentrations of dietary sucrose. The lowest dietary sucrose concentration at which honeydew oligosaccharides were detected was 0.2 mol l-1 for the antibiotic-treated aphids and 0.3 mol l-1 for untreated aphids. These data indicate that the aphid, and not its associated microbiota, mediates the synthesis of oligosaccharides when the osmotic pressure of the ingesta is high.

Journal Article↗
PubMed1996

Liver transplantation for Langerhans' cell histiocytosis--a case report and literature review.

Langerhans' cell histiocytosis (LCH) is a rare disorder of unknown etiology and pathogenesis. End-stage chronic liver disease is one presentation and orthotopic liver transplantation (OLT) has been reported in 17 cases, with variable resolution of LCH lesions postoperatively. We report a case of multisystem LCH with end-stage liver disease treated by OLT and review the overall results of OLT for children with LCH.

Child, Preschool↗
PubMed1996

Neurological sequelae of the dancing eye syndrome.

UNLABELLED: Fifty-four patients with dancing eye syndrome (DES), presenting over a 25-year period, were reviewed retrospectively. One third of them were on active follow up at the time of the study. Malignancy was uncommon, diagnosed in only 4 patients, neuroblastoma in 3 cases and acute lymphoblastic leukaemia (ALL) in 1. An intercurrent illness preceded onset of DES in 51% of the children and was of equivocal significance. There was no clear temporal relationship to immunization. The acute phase of the illness was severe and caused total immobilization in 88% of patients. A favourable initial response to treatment with prednisolone or corticotrophin gel was observed in all patients. Although corticotrophin seemed to produce a more rapid response, overall improvement was similar with both treatments. Long-term neurological morbidity was a major problem with 91% of children suffering either persisting symptoms or repeated relapses. A persisting disability was found in 88% and was considered severe in 61% of patients. No features prognostic of neurological severity or outcome were identified. CONCLUSION: Demonstrable malignancy is uncommon in the dancing eye syndrome. The neurological legacy of DES is often evident well into adult life.

Brain Damage, Chronic↗
PubMed1996

Growth, water relations and solute accumulation in osmotically stressed seedlings of the tropical tree Colophospermum mopane.

Root and hypocotyl elongation, water status and solute accumulation were studied in osmotically stressed seedlings of the tropical tree, Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Léonard, which grows in hot arid areas of southern and central Africa. Seeds were imbibed for 24 h and then subjected to a polyethylene-glycol-generated osmotic stress of -0.03 (control), -0.2, -0.8, -1.6 or -2.0 MPa for 60 h. Seedlings subjected to moderate water stress (-0.2 MPa) had higher root growth rates (2.41 +/- 0.24 mm h(-1)), greater final root lengths (111 +/- 3.8 mm) and longer cells immediately behind the root elongation zone than control seedlings (1.70 +/- 0.15 mm h(-1) and 93 +/- 3.9 mm, respectively). Root lengths of seedlings in the -0.8 and -1.6 MPa treatments were similar to those of control seedlings, whereas the -2.0 MPa seedlings had significantly shorter roots. Both root and hypocotyl tissues exhibited considerable osmotic adjustment to the external water potential treatments. Seedlings in the -0.03, -0.2, and -0.8 MPa treatments had similar cell turgor pressures (0.69 +/- 0.10, 0.68 +/- 0.07 and 0.57 +/- 0.04 MPa, respectively), whereas the -2.0 MPa treatment lowered cell turgor pressure to 0.17 +/- 0.04 MPa. Root vacuolar osmotic pressures were generally similar to sap osmotic pressures, indicating that the increased root elongation observed in moderately water-stressed seedlings was not caused by increased turgor pressure difference. Neutral-fraction solute concentrations, including the osmoticum pinitol, increased approximately two-fold in root sap in response to a low external water potential. In hypocotyl sap of seedlings in the -2.0 MPa treatment, pinitol more than doubled, sucrose increased from about 2 to 75 mol m(-3) but glucose and fructose remained unchanged and, as a result, total sugars increased only slightly. The benefits of rapid early root elongation and osmoticum accumulation under conditions of water stress are discussed in relation to seedling establishment.

Journal Article↗
PubMed1996

Langerhans cell histiocytosis and hypercalcemia: clinical response to indomethacin.

PURPOSE: Hypercalcemia is a known complication of childhood malignancies but has never been reported to be associated with Langerhans cell histiocytosis (LCH) in a pediatric patient. PATIENTS AND METHODS: We describe an infant with multisystem LCH who developed hypercalcemia on two occasions. After being placed on indomethacin, the hypercalcemia did not recur despite disease progression. CONCLUSION: Hypercalcemia may complicate LCH. If it is demonstrated, indomethacin should be considered as a treatment.

Cyclooxygenase Inhibitors↗
PubMed1996

Secondary amenorrhoea after total body irradiation in pre-puberty.

Bone marrow transplant (BMT) has been used as part of the overall treatment of refractory malignant diseases. High dose cyclophosphamide and total body irradiation (TBI) are frequently used as conditioning for BMT. Initial regimens included a single fraction of TBI, with doses varying from 7.5-10 Gy, but this was associated with a high incidence of late sequelae including multiple endocrinopathies. A fractionated irradiation course over 3-4 days of a higher total dose, 12-15 Gy, of TBI is now used. Successfully treated patients with childhood cancer have an increased risk, of developing second tumours. We describe a patient successfully treated for AML who developed multiple endocrine dysfunction and a second benign ovarian tumour.

Acute Disease↗