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Biomedical subjects

J A Kohler

Publications and source records attributed to J A Kohler.

At least 19 recordsLinked to original sources
PubMed2004

Tazobactam-induced haemolytic anaemia, possibly caused by non-immunological adsorption of IgG onto patient's red cells.

A patient with pneumonia was treated with Tazocin (piperacillin/tazobactam). However, the expected haemoglobin (Hb) increment after transfusion was not achieved. Plasma bilirubin and lactate dehydrogenase were raised. The direct antiglobulin test (DAT) was positive (4+) for immunoglobulin G (IgG) only, but no RBC antibodies were demonstrable in the plasma or an eluate from the patient's RBCs. Drug-induced haemolysis was suspected. After discontinuing Tazocin administration, Hb and bilirubin levels returned to expected values. The patient's plasma gave a positive (3+) indirect antiglobulin reaction only with RBCs pretreated with tazobactam. However, random patient plasmas also gave weak (+/- to 1+) reactions, indicating non-immunological adsorption of IgG onto RBCs rather than specific anti-tazobactam antibodies. Subsequently, plasma samples with varying IgG levels (0.8-89.7 g L(-1)) were tested against RBCs pretreated with tazobactam. The amount of plasma IgG non-immunologically adsorbed onto the drug-coated RBCs was found to correlate directly with the plasma IgG level. The patient had a high plasma IgG level (41.6 g L(-1)) which explains why the antiglobulin test was stronger with the patient's plasma than with random plasma samples. Previous reports (Garratty & Arndt, (1998) British Journal of Haematology, 100, 777-783; Arndt & Garratty (2000) Transfusion, 40, 29S) suggested that non-immunological coating of RBCs with IgG may affect RBC survival; our results would support that suggestion. This is the first reported case of haemolytic anaemia associated with tazobactam.

Adolescent↗
PubMed2001

Late relapse and prognosis for neuroblastoma patients surviving 5 years or more: a report from the European Neuroblastoma Study Group "Survey".

BACKGROUND AND PROCEDURE: Most deaths from neuroblastoma occur within 2 years of diagnosis but there have been several anecdotal reports of relapse and death after much longer periods of follow up. In order to investigate and quantify the risk of late events we analysed data for patients registered with the European Neuroblastoma Study Group between 1982 and 1990. Out of a total of 1,277 children registered, 427 were alive with follow-up beyond 5 years from diagnosis (median follow-up of 8.8 years, range 5-14 years). Of these 406 were in remission with no prior recurrence, 16 were in remission having experienced a relapse prior to 5 years, and 5 were alive with progressive disease. RESULTS: For the 406 patients in remission with no prior relapse the 10 year progression free survival (PFS) was 96% (CI 94-98). For those aged over 1 year with stage 4 disease at diagnosis 10 year PFS was 88% (CI 79-96) compared to 98% (CI 97-99) for other patients combined, P< 0.001. In a multivariate analysis of all 422 patients in remission at 5 years, significant risk factors for subsequent relapse were age > 1 yr with stage 4 disease at diagnosis (relative risk 10.5, P < 0.001) and prior relapse (RR 4.2, P= 0.01). CONCLUSIONS: The results of this study emphasise the importance of longterm follow-up of patients and the need for late monitoring of clinical trials in children with neuroblastoma. They also provide a baseline for comparison with future and hopefully more effective treatment programmes.

Abdominal Neoplasms↗
PubMed2000

Effect of fatty acid supplementation on growth and differentiation of human IMR-32 neuroblastoma cells in vitro.

Polyunsaturated fatty acids play a critical role in the structure and function of the developing nervous system. It has been proposed that fatty acids may effect a variety of biologic processes through the activation of the peroxisome proliferator activated receptors (PPARs)-ligand activated transcription factors. In this report, we demonstrate that fatty acids can inhibit the proliferation of the human neuronal cell line IMR-32. The fatty acids linoleate, alpha-linoleate, arachidonate, docosahexaenoate, and oleate all inhibited [(3)H]thymidine incorporation of IMR-32 cells after 72 h. Fatty acid supplementation also led to the morphologic differentiation of the IMR-32 cells. Linoleate and arachidonate, fatty acids of the n-6 series, induced the most extensive differentiation. Furthermore, the addition of fatty acids to IMR-32 cells led to PPAR activation, suggesting that PPAR activation may be an important event in fatty acid modulation of IMR-32 cell growth. In support of this hypothesis, clofibric acid, a specific ligand of PPARalpha, also inhibited IMR-32 cell proliferation and strongly induced PPAR activation. Together these results suggest that fatty acids may play an important role in the development of neuronal precursor cells and that activation of the PPARs may be one pathway by which fatty acids modulate the growth and differentiation of neuronal precursor cells.

Cell Differentiation↗
PubMed2000

Clinical prognostic factors in 1277 patients with neuroblastoma: results of The European Neuroblastoma Study Group 'Survey' 1982-1992.

In 1982 the European Neuroblastoma Study Group (ENSG) established a prospective registry for patients with newly diagnosed neuroblastoma ('The ENSG Survey'). Clinical information was collected primarily to: (a) establish an ENSG database; and (b) investigate prognostic factors in neuroblastoma. This paper summarises the results of the survey. By 1992, 1277 patients with a median age of 26 months (range: 0-289 months), gender ratio of 1.19 M:F had been registered from 30 centres. The median follow-up of survivors is 9.7 years (range: 1-14 years). Overall 5-year survival (S) is 45% (95% CI 42-48%), and event-free survival (EFS) is 43% (95% CI 40-45%). For both survival and EFS the key established prognostic factors, stage and age, are highly significant (P<0.001). In particular, patients under 1 year of age at diagnosis, whatever the disease stage, had a more favourable prognosis than older patients; stage 2 (EFS 93% (95% (CI 85-97) versus 76% (95% CI 67-86), P=0.02), stage 3 (EFS 91% (95% CI 82-96) versus 52% (95% CI 44-60), P<0.001) and stage 4 (EFS 59% (95% CI 48-69) versus 16% (95% CI 13-19), P<0.001). Multivariate analysis established that the anatomical location of the primary tumour (i.e. abdominal versus other sites) and primary tumour volume also conferred a statistically significant difference. In stage 4 disease the 20% of patients without demonstrable bone marrow involvement had a more favourable prognosis than those with infiltrated marrow (EFS 36% (95% CI 13-19) versus 16% (95% CI 29-45), P<0.001). Urine catecholamine metabolite levels (raised versus normal), histology (ganglioneuroblastoma versus neuroblastoma) and gender had no significant effect on outcome after stage and age were accounted for. 5-year survival following first relapse is only 5.6% (95% CI 2.8-8.4). This ENSG Survey provides secure data for future comparisons with new prognostic factors and treatment programmes.

Adolescent↗
PubMed1999

Comparative genomic hybridization and histological variation in primitive neuroectodermal tumours.

The objective of this study was to test the hypothesis that chromosomal imbalances in central nervous system primitive neuroectodermal tumours (PNETs) reflect site and histology. We used comparative genomic hybridization to study 37 cases of PNET, of which four were cerebral and 31 were medulloblastomas classified histologically as classic (n = 17) or nodular/desmoplastic (n = 14). Tumour immunophenotype was characterized with antibodies to neuroglial, mesenchymal and epithelial markers. Chromosomal imbalances were detected in 28 medulloblastomas (90%), and significant associations between tumour variants and genetic abnormalities were demonstrated. Aberrations suggesting isochromosome 17q were present in eight (26%) medulloblastomas, of which seven were classic variants. None of these cases, or a further six with gain of 17q, showed immunoreactivity for glial fibrillary acidic protein. Loss on 9q was found in six cases (19%), five of them nodular/desmoplastic. Loss of 22 occurred in four (13%), all classic medulloblastomas in young patients with a poor outcome and immunoreactivity for more than one epithelial or mesenchymal marker. Different patterns of imbalance were found in the cerebral PNETs. There were no abnormalities of chromosome 17, but all three cases with imbalance showed losses of 3p12.3-p14.

Adolescent↗
PubMed1994

Therapy of human T-cell acute lymphoblastic leukaemia in severe combined immunodeficient mice with two different anti-CD7-saporin immunotoxins containing hindered or non-hindered disulphide cross-linkers.

A SCID mouse model of human T-ALL has been used to determine the in vivo therapeutic efficacy of two anti-CD7-saporin immunotoxins constructed with either a hindered (HB2-SMPT-Sap) or non-hindered (HB2-SPDP-Sap) disulphide bond between antibody and saporin. Groups of 10 SCID mice were injected intravenously (i.v.) with 2 x 10(6) human T-ALL HSB-2 cells followed seven days later by i.v. injection with either a single dose or with 3 doses of HB2-SPDP-Sap or HB2-SMPT-Sap given on alternate days. Control groups received equivalent sham injections of PBS or molar equivalent amounts of unconjugated HB2 antibody+saporin. Animals receiving a single dose of HB2-SMPT-Sap showed better survival than animals receiving a single dose of HB2-SPDP-Sap but the difference was not shown to be significant by log-rank analysis. When given as a triple dose both immunotoxins performed similarly. Comparison of single-dose with triple-dose IT therapy revealed that the therapeutic effect of a triple dose of HB2-SPDP-Sap was significantly better than that of single dose, but this was not the case with HB2-SMPT-Sap. Pharmacokinetic studies of HB2-SPDP-Sap and HB2-SMPT-Sap in normal and HSB-2 leukaemia bearing SCID mice failed to reveal any difference in clearance rates for these two IT's. We conclude from these studies that there is no therapeutic advantage to be gained from constructing the HB2-Sap IT with a hindered disulphide bond in this particular model of human T-ALL.

Animals↗
PubMed1994

Immunotoxin studies in a model of human T-cell acute lymphoblastic leukemia developed in severe combined immune-deficient mice.

The transplantation of the human T-cell acute lymphoblastic leukemia (T-ALL) cell line HSB-2 into severe combined immune-deficient (SCID) mice was found to produce a disseminated pattern of leukemia similar to that seen in humans. The iv injection of 10(7) HSB-2 cells was associated with a universally fatal leukemia. Histopathological examination of animals revealed the spread of leukemia initially from bone marrow to involve all major organs including the meninges. An immunotoxin (HB2-Sap) was constructed by conjugating the anti-CD7 monoclonal antibody (MAb) HB2 to the ribosome inactivating protein (RIP) saporin. An in vitro protein synthesis inhibition assay revealed specific delivery of HB2-Sap immunotoxin (IT) to CD7+ HSB-2 target cells with an IC50 of 4.5 pM. In an in vivo study, the IT was shown to significantly prolong the survival of SCID mice injected with HSB-2 cells compared to untreated control animals. This therapeutic effect was seen both with a single injection of 10 micrograms of IT given 7 d after the injection of HSB-2 cells, and was even more effective when IT was administered as three daily injections of 10 micrograms on d 7, 8, and 9. These results demonstrate the useful application of human leukemia xenografts in SCID mice and the potential therapeutic effect of an anti-CD7 IT in human T-ALL.

Animals↗
PubMed1994

Low dose long-term corticosteroid therapy in rheumatoid arthritis: an analysis of serious adverse events.

PURPOSE: The purpose of this study was to better define the toxicity of low dose (less than or equal to 15 mg/d prednisone or equivalent) long-term (greater than 1 year) corticosteroids in the treatment of rheumatoid arthritis (RA). PATIENTS AND METHODS: We examined an historical cohort of 112 RA patients on low dose (6.1 +/- 3.1 mg/d, mean +/- SD) long-term (6.2 +/- 4.6 years) prednisone (CS) and compared them to 112 matched RA patients not using prednisone (CO). CS were matched one-to-one with CO for sex (75% women), age (+/- 5 yrs), race (98% white), and duration of disease (+/- 5 yrs). Subjects were determined by review of unselected medical records from three distinct rheumatology practice settings. For CS, charts were abstracted from the date of prednisone start for predefined adverse events (AEs). RESULTS: Ninety-two (92) AEs were noted in CS versus 31 in CO and included: fracture (CS:21 versus CO:8), serious infections (CS:14 versus CO:4), gastrointestinal (GI) bleed or ulcer (CS:11 versus CO:4), and cataracts (CS:17 versus CO:5). At time of first AE, CS prednisone average dose was 7.0 +/- 2.6 mg with a duration of 4.9 +/- 3.9 years. Stepwise multiple logistic regression analysis was used to create a model which included all clinically relevant variables and all parameters significantly different at the cohort inception. Prednisone average dose of greater than 10 to less than or equal to 15 mg/d correlated most strongly with the development of an AE (Odds Ratio (OR) = 32.3, 95% Confidence Interval (CI) 4.6, 220). Average prednisone 5 to 10 mg (OR = 4.5, 95% CI 2.1, 9.6), RA nodules (OR = 3.9, 95% CI 1.9, 8.0), and bony erosions (OR = 2.4, 95% CI 1.2, 4.7) also entered the final model. Kaplan Meier survival curves for the development of the first AE showed a dose-response relationship between prednisone and AE occurrence, independent of rheumatoid nodules. Subset analyses utilized a nested case control design for the development of three serious AEs: fractures, serious infections, and GI events. These analyses revealed possible relationships between prednisone use and the development of each specific AE (prednisone use OR: fracture 3.9, 95% CI 0.8, 18.1; infection 8.0, 95% CI 1.0, 64.0; and GI event 3.3, 95% CI 0.9, 12.1). CONCLUSIONS: Although disease severity is an important confounding factor, low dose long-term prednisone use equal to or greater than 5 mg/d is correlated with the development of specific adverse events in a dose-dependent fashion.

Adult↗
PubMed1994

Effectiveness of HB2 (anti-CD7)--saporin immunotoxin in an in vivo model of human T-cell leukaemia developed in severe combined immunodeficient mice.

The transplantation of the human T-cell acute lymphoblastic leukaemia (T-ALL) cell line HSB-2 into severe combined immunodeficient (SCID) mice was found to produce a disseminated pattern of leukaemia similar to that seen in man. The intravenous injection of 10(7) HSB-2 cells was associated with a universally fatal leukaemia. Histopathological examination of animals revealed the spread of leukaemia initially from bone marrow to involve all major organs including the meninges. An immunotoxin (HB2-Sap) was constructed by conjugating the anti-CD7 MAb HB2 to the ribosome-inactivating protein saporin. An in vitro protein synthesis inhibition assay revealed specific delivery of HB2-Sap immunotoxin (IT) to CD7+ HSB-2 target cells with an IC50 of 4.5 pM. When SCID mice were injected with 10(6) HSB-2 cells and then treated 8 days later with a single intravenous dose of 10 micrograms of immunotoxin there was a significant therapeutic effect evidenced by the numbers of animals surviving in the therapy group compared with untreated controls (chi 2 = 5.348, P = 0.021). These results demonstrate the useful application of human leukaemia xenografts in SCID mice and the potential therapeutic effect of an anti-CD7 immunotoxin in human T-ALL.

Animals↗
PubMed1992

Energy intake and basal metabolic rate during maintenance chemotherapy.

Energy intakes and basal metabolic rates were determined in 26 children receiving chemotherapy in remission from acute lymphoblastic leukaemia or solid tumours and 26 healthy controls matched for age and sex. Body weight and height on the two groups were comparable, although one patient was stunted (height for age) and three others wasted (weight for height). Energy intake in the patients at 7705 kJ/day (1842 kcal) and controls at 7773 kJ/day (1866 kcal)) and basal metabolic rate (BMR) in the patients at 4873 kJ/day (1172 kcal) and controls 4987 kJ/day (1196 kcal) for the two groups were not significantly different. Although the energy intake:BMR ratio for both groups was 1.59, the range of values for the patient group was large (0.96-2.73) and appeared to be greater than that observed in the control group (1.23-2.46). These results demonstrated that during this period of chemotherapy there was no evidence of raised energy expenditure at rest or reduced energy intake in the patient group. No indication of undernutrition in the patients as a group was evident, although some individuals might require further clinical nutritional assessment.

Adolescent↗
PubMed1990

Erythrocyte fatty acid profiles in childhood malignancy.

The erythrocyte fatty acid composition was determined for 79 children using gas chromatography. The stearic:oleic acid ratio (SOR) was significantly lower in those children with newly diagnosed malignancies than in a reference group of healthy children. However, a control group of children with chronic, non-malignant conditions were also found to have a low SOR. These results suggest that the erythrocyte SOR cannot be used as a tumour marker in children.

Adolescent↗
PubMed1990

Adverse experience with methotrexate during 176 weeks of a longterm prospective trial in patients with rheumatoid arthritis.

Adverse experience occurred with a high frequency in a longterm (greater than 3 years), prospective, double blind, followed by an open trial of methotrexate (MTX) therapy in 45 patients with rheumatoid arthritis (RA). Adverse experiences occurred in 96% of patients, and the discontinuation rate was 44% over 176 weeks. No hepatic or pulmonary fibrosis occurred. Unusual toxicities included weight loss (2 patients), systemic fungal infections (2 patients), and transient noncirrhotic ascites (1 patient). Baseline white blood cell counts and creatinine may help predict adverse experiences. The full dose-toxicity spectrum of MTX RA is not yet fully defined.

Arthritis, Rheumatoid↗
PubMed1987

Anterior ischemic optic neuropathy. VII. Incidence of bilaterality and various influencing factors.

A prospective study was conducted in 438 patients with anterior ischemic optic neuropathy (AION). There were 388 patients with nonarteritic AION and 50 with arteritic AION. The risk of bilaterality in patients with arteritic AION was found to be 1.9 times the risk in patients with nonarteritic AION (P = 0.0118). The cumulative incidence curve, considering the time taken to develop bilateral AION for nonarteritic cases was significantly (P = 0.0103) different from that for arteritic cases. The estimated 25th-percentile time to development of bilateral AION was much shorter in patients with arteritic AION (0.4 month) than in those with nonarteritic AION (32.4 months). In arteritic AION, unilateral as well as bilateral AION had almost invariably developed before systemic steroid therapy was started and not after, indicating that this therapy is effective in preventing the development of AION in giant cell arteritis. In nonarteritic AION, the risk of bilaterality was significantly greater in men (P = 0.0113) and in young (less than 45 years old) patients with diabetes (P = 0.0245), with no significant difference attributable to the other age groups or other associated systemic diseases. In this study, it was found that young diabetic men have a risk of AION developing in the second eye that is 1.56 times the risk in young diabetic women, 2.56 times the risk in women who either are nondiabetic or are not young, and 1.64 times the risk in both older men and nondiabetic men.

Adolescent↗