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Biomedical subjects

B Lange

Publications and source records attributed to B Lange.

At least 19 recordsLinked to original sources
PubMed1999

Hypoxic upregulation of tyrosine hydroxylase gene expression is paralleled, but not induced, by increased generation of reactive oxygen species in PC12 cells.

Oxygen sensing was investigated in rat pheochromocytoma PC12 cells. They respond to hypoxia with an increased intracellular generation of reactive oxygen species (ROS), measured by oxidation of dihydrorhodamine 123. This increase is abolished by intracellular superoxide scavenging by Mn(III)-tetrakis(1-methyl-4-pyridyl)-porphyrin, and reduced or absent in the presence of the flavoprotein/complex I inhibitors, diphenyl-eneiodonium and rotenone. The same inhibitors, but neither intra- nor extracellular (superoxide dismutase) superoxide scavenging, abolish the hypoxia-induced increase in tyrosine hydroxylase (TH) gene expression. Thus, ROS production increases in PC12 cells during hypoxia, but this is not the cause of hypoxic TH mRNA upregulation that involves a flavoprotein.

Animals↗
PubMed1999

Poor treatment outcome of Philadelphia chromosome-positive pediatric acute lymphoblastic leukemia despite intensive chemotherapy.

Children with Philadelphia (Ph) chromosome positive (+) acute lymphoblastic leukemia (ALL) represent a subgroup at very high risk for treatment failure. This study included 1322 children enrolled between 1988 and 1994 on CCG risk-adjusted studies for ALL who had centrally reviewed cytogenetic data. Thirty patients had a t(9;22) and are referred to as Ph+; 1292 were Ph-. 23 of these 30 patients were treated on the CCG-1882 high risk ALL protocol. The event-free survival (EFS) outcome in CCG-1882 was significantly worse for Ph+ compared with Ph- patients, with 4-year estimates of 11.3% (SD = 9.8%) and 73.4% (SD = 2.3%), respectively (p < 0.0001).

Antineoplastic Agents↗
PubMed1998

Clinical significance of Philadelphia chromosome positive pediatric acute lymphoblastic leukemia in the context of contemporary intensive therapies: a report from the Children's Cancer Group.

BACKGROUND: Children with Philadelphia (Ph) chromosome positive (+) acute lymphoblastic leukemia (ALL) represent a subgroup at very high risk for treatment failure. In this report, the authors assessed the outcome of Ph+ ALL in a large cohort of children treated on contemporary intensive chemotherapy protocols of the Children's Cancer Group (CCG). METHODS: This study included 1322 children enrolled between 1988-1995 on CCG risk-adjusted studies for ALL who had centrally reviewed cytogenetic data. Thirty patients had a t(9;22)(q34;q11) translocation and were referred to as Ph+; 1292 were Ph negative(-). Outcome analyses used standard life table methods. RESULTS: Compared with Ph- ALL patients, Ph+ ALL patients were more likely to be black (P=0.008), age >10 years (P=0.02), and have a leukocyte count > or =50,000/L (P <0.0001). Nearly all Ph+ (96.7%) and Ph (98.3%) patients achieved remission after induction therapy, yet event free survival outcome was significantly worse for Ph+ patients compared with Ph- patients, with 4-year estimates of 20.1% (standard deviation [SD] = 9.1%) and 75.8% (SD =1.2%), respectively (P <0.0001). This difference was maintained among patients regardless of presenting leukocyte count, age, or early response to therapy. Ten Ph+ patients underwent bone marrow transplantation (BMT) at the time of first remission; six of these patients remained event free at the time of analysis, and represent the majority (six of eight) of patients surviving event free. CONCLUSIONS: The findings of the current study confirm that Ph chromosome positivity represents a significant independent adverse risk factor for childhood ALL that has not been abrogated by current intensive chemotherapy programs. BMT at the time of first remission, as well as other alternative strategies employing biotherapeutic agents, should be considered in future front-line trials for pediatric patients with Ph+ ALL.

Bone Marrow Transplantation↗
PubMed1998

Does short-term antiepileptic drug treatment in children result in cognitive or behavioral changes?

PURPOSE: To determine possible cognitive and behavioral effects of antiepileptic drug (AED) therapy by assessing children with newly diagnosed epilepsy before and after initiation of treatment. A comparison group of children with diabetes mellitus (DM) was included to control for the effects of practice, maturation, and chronic illness. METHODS: Baseline neuropsychological assessments were completed for children with epilepsy (n = 37) and children with DM (n = 26) recruited through outpatient clinics at a regional children's hospital. Children were reevaluated 6 months from baseline testing. At follow-up, children with epilepsy had therapeutic AED levels and controlled seizures. Statistical analysis included a between-group repeated measures ANCOVA with pretest scores serving as the covariate. RESULTS: Significant differences between groups were not found for any cognitive or behavioral factors, including attention (p < 0.24), immediate memory (p < 0.24), delayed memory (p < 0.10), complex motor speed (p < 0.19), or behavior problems (p < 0.89). CONCLUSIONS: Changes in performance on cognitive and behavioral measures were not different for children treated with AEDs and controls. Although adverse effects may be associated with prolonged treatment, results would not suggest adverse effects from AED monotherapy during the first 6 months of therapy.

Adolescent↗
PubMed1998

Stimulation of mitogen activated protein kinase and cellular proliferation in renal proximal tubular cells.

We have studied activation of mitogen-activated protein kinase (MAP kinase) and [3H]-thymidine uptake as a marker for cellular proliferation in a proximal tubular cell line of the American Opossum kidney (OK cells). Adrenaline, serotonin, epidermal growth factor and insulin all stimulated MAP kinase and [3H]-thymidine uptake. This stimulation of cellular proliferation was markedly reduced by an inhibitor of the MAP kinase pathway, PD 98059. Epidermal growth factor stimulated MAP kinase activity more effectively than the other agonists, but all four had similar effects on OK cellular proliferation. These data indicate that amine neurotransmitters may be of similar importance for tubular regeneration as classical growth factors.

Animals↗
PubMed1997

Features, symptoms, and neurophysiological findings in stroke associated with hyperhomocysteinemia.

BACKGROUND: Hyperhomocysteinemia has been shown to be a mild independent risk factor for premature atherosclerosis, and there is evidence of an increased rate of peripheral vascular occlusive disease, myocardial infarction, and stroke. OBJECTIVE: To evaluate clinical, biochemical, and neurophysiological findings in patients with ischemic stroke with and without hyperhomocysteinemia. SUBJECTS: One hundred twenty-five consecutive patients with a history of stroke and 60 healthy control subjects. METHODS: Patients were divided into those with and those without hyperhomocysteinemia, which was defined as blood levels beyond the mean total plasma homocysteine level plus 2 SDs of the healthy control group. History, symptoms, cause, patterns of infarction, biochemical data, continuous and transcranial Doppler sonography, and event-related potentials were recorded in all patients. RESULTS: Twenty-seven patients had hyperhomocysteinemia. Compared with the 98 patients without hyperhomocysteinemia, they had an increased rate of hypertension (odds ratio, 3.5; 95% confidence interval, 1.0-12.6), an increased level of uric acid (P < .007), an increased hematocrit (P < .02), a higher rate of microangiopathy (odds ratio, 2.8; 95% confidence interval, 1.1-7.2), and a trend to a higher rate of multiple infarction. Furthermore, the P3 latency of the event-related potential was significantly increased in hyperhomocysteinemia (P < .004). CONCLUSIONS: Hyperhomocysteinemia is probably an independent risk factor for stroke, with a prevalence of about 20% in all patients with a history of stroke; however, additional factors (eg, hypertension, hyperuricemia) may have an enhancing effect. There are significant differences in stroke patterns between patients with and without hyperhomocysteinemia, with a higher rate of lesions typical of cerebral microangiopathy and a trend to multiple infarctions in the former. Impairment of cognitive processing as measured by visual event-related potential is more pronounced in hyperhomocysteinemia.

Adult↗
PubMed1997

Alpha2-adrenoceptors in opossum kidney cells couple to stimulation of mitogen-activated protein kinase independently of adenylyl cyclase inhibition.

We have compared the effects of adrenaline on activation of mitogen-activated protein kinase (MAP kinase), cyclic AMP accumulation and [3H]thymidine uptake in OK cells, a cell line derived from proximal tubules of the opossum kidney. Effects of serotonin and the direct protein kinase C activator, phorbol-12-myristate-13-acetate (PMA), were also studied. Adrenaline transiently (peak at 5 min, return to baseline by 30 min) and concentration-dependently (EC50 between 10 and 100 nM) stimulated MAP kinase activity. Maximal stimulation was approximately 100% above basal and was similar to the effects of 1 microM serotonin or 1 microM PMA. MAP kinase activation by adrenaline was inhibited by 10 microM phentolamine or 1 microM yohimbine but not significantly affected by 100 nM prazosin or 200 nM pindolol. The selective alpha2-adrenoceptor agonist UK 14,304 (10 microM) also stimulated MAP kinase activity. Activation of the 42 and 44 kDa ERK forms of MAP kinase was demonstrated by immunoblot analysis. The effect of adrenaline and UK 14,304 on MAP kinase was inhibited by pertussis toxin pretreatment and by the MAP kinase kinase inhibitor, PD 98059 (100 microM). Stimulation of MAP kinase activity was independent of cellular cAMP levels and was not affected by protein kinase C downregulation. Adrenaline, UK 14,304, serotonin, and PMA stimulated [3H]thymidine uptake, an effect inhibited by PD 98059. We conclude that adrenaline stimulates MAP kinase activity in OK-cells via alpha2-adrenoceptors and pertussis sensitive G proteins. While this occurs independently of cellular cAMP levels and protein kinase C, it involves the MEKI form of MAP kinase kinase and the ERK forms of MAP kinase. This activation results in enhanced cellular proliferation as assessed by [3H]thymidine uptake.

Adenylate Cyclase Toxin↗
PubMed1997

Oncologic emergencies.

The prognosis for the child with cancer has improved dramatically over the past decades. With this success comes the need for recognition and proper treatment of emergencies. Respiratory or circulatory failure may arise from compression of the SVC or airway. Epidural spinal cord compression by tumor may lead to irreversible paraplegia or urinary incontinence if intervention is not rapid. Raised intracranial pressure may be a life-threatening presentation of a brain tumor. Bone marrow failure, with anemia and thrombocytopenia, is associated with malignant infiltration of the marrow. Hyperleukocytosis carries a high risk of thrombotic events if not treated promptly. Coagulation abnormalities are seen in many childhood cancers at the time of diagnosis. Life-threatening metabolic abnormalities are observed at presentation in children with leukemia and lymphoma. Hypercalcemia, although rare, may be a difficult situation to correct. Immediate attention to these emergencies and appropriate treatment may save the life of a child with cancer or make his or her subsequent course just a little smoother.

Algorithms↗
PubMed1996

Behavioral descriptors that differentiate between seizure and nonseizure events in a pediatric population.

The diagnosis and treatment of epilepsy relies heavily on descriptions of behavioral changes noted during seizure episodes. A pilot study was completed to determine the frequency of occurrence of behaviors commonly associated with seizures in a pediatric population (n = 153). Caretakers of the children (ages = 4 months to 19 years) were asked to respond to a checklist containing 40 behavioral descriptors. Thirteen descriptors were found to differentiate between seizure and nonseizure events. Twelve of these behaviors were endorsed significantly more frequently by caretakers of children with seizures including the following: does not remember what happened, moves mouth funny, drools, jerking/twitching, becomes stiff, changes in breathing, stares off, bites or chews tongue, eyes look glassy, will not respond, mumbles or slurs words, and eyes or head turn to one side. One behavior, fidgets in seat, was significantly more associated with nonseizure episodes. The behavioral descriptors may be presented in a checklist format or incorporated within a clinical interview in primary care settings for initial screening of children with possible seizure disorders.

Adolescent↗
PubMed1996

Sequential combination of radio-chemotherapy (5-fluorouracil, cis-platinum and irradiation) in the management of locally advanced head and neck cancers.

Thirty-seven previously untreated patients with advanced, inoperable head and neck were treated with a sequential courses combining hypofractionated irradiation with chemotherapy (5-fluorouracil and cis-platinum). Each course was repeated every 4 weeks. Tumor response was evaluated and for 15 patients (41%) with a partial or complete regression after 3 radio-chemotherapy courses conventional radiotherapy was added. Eleven percent of all patients were in complete remission at the end of a treatment. This tumor response rate and the 50% rate of pain subside after first course for symptomatic patients contributed for a good palliative effect in the present study. However, the median survival of 7.2 months was considered unsatisfactory.

Adult↗
PubMed1995

A phase I trial of amifostine (WR-2721) and melphalan in children with refractory cancer.

Melphalan has a steep dose-response curve, but the use of high doses results in unacceptable myelosuppression. Strategies to circumvent this dose-limiting myelosuppression would allow for the administration of higher, more effective doses of melphalan. Amifostine (WR-2721) has been shown in preclinical studies to protect the bone marrow from the myelotoxicity of melphalan, and in clinical trials, to protect from the myelotoxicity of other alkylating agents. A Phase I trial of the combination of amifostine and melphalan was performed in children with refractory cancers to: (a) define the acute toxicities of amifostine and its maximum tolerated dose (MTD); and (b) to determine whether the dose of melphalan could be safely escalated when administered in combination with amifostine. Amifostine was administered i.v. as a 15-min infusion 30 min before melphalan. The starting dose of amifostine was 750 mg/m2, with planned dose escalations in 30% increments. Melphalan was administered as a 5-min infusion using the previously defined MTD in heavily pretreated patients, 35 mg/m2, as the starting dose. The dose of melphalan was escalated by 30% increments. Nineteen patients, ranging in age from 3 to 24 years (median, 15 years), were entered on trial. The dose of amifostine was escalated to 2700 mg/m2, which is approximately 3-fold higher than the adult recommended dose, without reaching a MTD. Fifteen patients experienced nondose-limiting (< 25%), transient decreases in blood pressure after the amifostine infusion. Other nondose-limiting toxicities of amifostine included mild nausea and vomiting, flushing, anxiety, diarrhea, and urinary retention. Six patients, three each at the 2100 and 2700 mg/m2 amifostine dose levels were treated with an escalated dose of melphalan (45 mg/m2). All of these patients experienced grade 4 neutropenia (< 500/mm3), and five of six patients had grade 4 thrombocytopenia. The duration of this dose-limiting myelosuppression exceeded 7 days in four of six patients. Although no dose-limiting (grade 3 or 4) toxicity was attributed to amifostine, significant anxiety and reversible urinary retention occurred at the two highest amifostine dose levels. A dose of 1650 mg/m2 for pediatric Phase II trials is recommended. High doses of amifostine, however, do not appear to allow for escalation of melphalan beyond its single agent MTD of 35 mg/m2.

Adolescent↗
PubMed1995

A randomized, controlled trial of the efficacy of a heparin and vancomycin solution in preventing central venous catheter infections in children.

OBJECTIVE: To determine whether adding vancomycin to central venous catheter (CVC) flush solution would significantly reduce the incidence of bacteremia attributable to luminal colonization with vancomycin-susceptible organisms. STUDY DESIGN: Fifty-five children with cancer and eight children given total parenteral nutrition by the surgery or nutrition support services were randomly assigned to receive a heparin CVC flush solution (n = 31) or a heparin-vancomycin CVC flush solution (n = 32). RESULTS: During 9158 catheter days, 6.5% of the patients in the heparin group and 15.6% of the patients in the heparin-vancomycin group had bacteremia attributable to luminal colonization with vancomycin-susceptible organisms (p = 0.43). The mean rates of bacteremia attributable to luminal colonization with vancomycin-susceptible organisms were 0.6/1000 catheter days in the heparin group and 1.4/1000 catheter days in the heparin-vancomycin group (p = 0.25). There was no significant difference between the groups when the time to the first episode of bacteremia attributable to luminal colonization with a vancomycin-susceptible organism was compared by means of Kaplan-Meier survival estimates. Streptococcus viridans infection was not attributable to luminal colonization. CONCLUSION: The addition of vancomycin to heparin CVC flush solution did not reduce bacteremia with vancomycin-susceptible organisms. Bacteremia with Streptococcus viridans was not related to the use of a CVC.

Adolescent↗
PubMed1995

Congenital erythropoietic porphyria associated with nephrotic syndrome and renal siderosis.

A 9-year-old boy with typical features of congenital erythropoietic porphyria who had received more than 50 blood transfusions developed the steroid-resistant nephrotic syndrome in the presence of normal glomerular function and glucosuria. Renal biopsy showed focal segmental glomerulosclerosis and widespread iron deposits. Magnetic resonance scanning revealed advanced siderosis of liver and kidneys. During a 4 year treatment by desferrioxamine the serum ferritin level was reduced, proteinuria dropped and serum proteins increased whilst glomerular filtration decreased slowly. It is suggested that the nephrotic syndrome may be a consequence of renal siderosis amenable to iron-chelating therapy.

Anti-Inflammatory Agents↗
PubMed1995

Long-term outcome of hypothalamic/chiasmatic astrocytomas in children treated with conservative surgery.

The feasibility of radical surgery for astrocytomas of the optic chiasm/hypothalamus has been reported by several groups. Such surgery carries significant risks, however, including permanent damage to the pituitary gland, optic apparatus, hypothalamic structures, and carotid arteries. The benefits of radical surgery, both in terms of efficacy and toxicity, should, therefore, be evaluated against standard therapy, as is usually done for new chemotherapeutic protocols. To this end, a retrospective review was performed of 33 patients treated at Children's Hospital of Philadelphia between 1976 and 1991 who met criteria that would have made them eligible for radical surgery in many centers today, but were treated with either no surgery or conservative surgery (< 50% resection) or biopsy followed by adjuvant therapy with local radiation therapy (29 patients) and/or chemotherapy with actinomycin-D and vincristine (18 patients). The review encompassed all children with a globular enhancing mass of at least 2 cm in the hypothalamic/chiasmatic region, no evidence of optic nerve involvement or involvement of the optic radiations by computerized tomography or magnetic resonance imaging, and follow up of at least 3 years. All but one patient had tissue confirmation of a low-grade or pilocytic astrocytoma. Thirteen of the patients were 2 years of age or younger at diagnosis. Five individuals died: three of tumor progression, one of acute shunt malfunction, and one of intercurrent infection. The remaining 28 were alive at last follow up, a mean of 10.9 years from diagnosis. Twenty-three surviving patients have functional vision in at least one eye, 12 require no endocrine replacement, and 16 are in or have completed schooling with regular academic requirements. If radical surgery is to become standard care for children with low-grade astrocytomas of the hypothalamic/chiasmatic region, long-term survival and functional outcome will have to equal or surpass those of historical controls who were treated conservatively.

Adolescent↗
PubMed1995

A prospective, controlled evaluation of home chemotherapy for children with cancer.

OBJECTIVES: Infusion of chemotherapy at home provides an alternative to hospitalization for children with cancer. Few programs of pediatric home chemotherapy have been described or evaluated. The purpose of this work was to compare prospectively chemotherapy in the hospital to chemotherapy at home with respect to billed medical charges, out-of-pocket expenses, and quality of life. METHODS: Eligibility criteria for home therapy were defined. Parents and nurses were trained. Billed charges, loss of wages, out-of-pocket expenses, medical outcome, and quality of life of 14 patients for one course of chemotherapy in the hospital were compared with those for an identical course at home. RESULTS: Daily charges for chemotherapy were $2329 +/- 627 in the hospital and $1865 +/- 833 at home; out-of-pocket costs, $68 +/- 31 and $11 +/- 6, respectively; and loss of income, $265 +/- 233 and $67 +/- 107, respectively. Patients' independence, well-being, appetite, mood, and school work were significantly better at home, and parental time at work and with the family was greater. CONCLUSION: Administration of selected chemotherapy at home results in lower billed charges, reduced expenses, reduced loss of income for parents, and a more satisfying lifestyle for patients and parents.

Adolescent↗