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Biomedical subjects

B Lange

Publications and source records attributed to B Lange.

At least 55 records · Page 3Linked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

The impact of perioperative factors on subsequent intelligence quotient deficits in children treated for medulloblastoma/posterior fossa primitive neuroectodermal tumors.

BACKGROUND: Despite success in treating children with medulloblastoma/posterior fossa primitive neuroectodermal tumor (PF PNET), some children survive with significant neurocognitive sequelae. This study was performed to understand better the significance of perioperative factors on subsequent full scale intelligence quotient (FSIQ) deterioration in these children. METHODS: Twenty-eight children who underwent prospective and serial neurocognitive testing were studied. All children underwent surgery followed by radiotherapy with or without chemotherapy between 1983 and 1987 for medulloblastoma/PF PNET and were disease free when this study was conducted. IQ testing was performed before surgery and after the completion of radiation therapy. The clinical courses of the patients were correlated with changes in the corresponding intelligence quotients of each child. Factors correlating with neurocognitive declines were examined by chi-square or Fisher exact test analysis. Differences in mean IQs were examined by the t test. Factors found to be significant were analyzed by exact logistic regression analysis. RESULTS: The presence of adverse factors such as neurologic deficits, meningitis, or shunt infections, or the need for repeat surgery was correlated significantly with IQ deficits after treatment. Of the subset of children with one or more of these factors, 13 of 16 (81%) sustained decreases in FSIQ; 7 of 16 (43.8%) had decreases of 20 points of more. In contrast, only 3 of 12 (25%) of the children without the factors sustained FSIQ decreases, and no child sustained a decrease of more than 13 points. The mean FSIQ change after treatment in the group with factors was -15.7 (95% confidence interval [CI]: -24.0, -8.4), and the median was -18. The mean FSIQ change in the group without factors was 4.8 (95% CI: -0.5, 10.1), and the median was 5. The difference in mean FSIQ change between the two groups was significant (P < 0.0001). On univariate analysis, both the presence of adverse factors and an age less than six years correlated with neurocognitive deficit. On regression analysis, only the presence of adverse factors was significant (odds ratio 11.53; 95% CI, 1.65-116.58; P = 0.009), whereas age was not (P = 0.27). CONCLUSIONS: Perioperative events or complications may account for some of the neurocognitive deterioration seen in these children after treatment, especially in the very young. The occurrence of these factors is associated with a significantly greater risk of IQ deterioration. Studies of the neurocognitive effects of treatment for children with medulloblastoma/PF PNET should include an analysis of these postoperative factors.

Adolescent↗

Pyrene Metabolism in Crinipellis stipitaria: Identification of trans-4,5-Dihydro-4,5-Dihydroxypyrene and 1-Pyrenylsulfate in Strain JK364.

The isolation and identification of two novel metabolites in the fungal metabolism of pyrene are described. The plant-inhabiting basidiomycete Crinipellis stipitaria JK364 metabolized pyrene, a polycyclic aromatic hydrocarbon containing four rings, when grown in submerged cultures in a medium containing malt extract, glucose, and yeast extract. In experiments with [C] pyrene, after 7 days of incubation 40% of the labeled substrate was converted into organic solvent-extractable metabolites. Metabolites isolated from cultures grown with pyrene were identified as 1-pyrenylsulfate and trans-4,5-dihydro-4,5-dihydroxypyrene. 1-Hydroxypyrene, the precursor of 1-pyrenylsulfate, was also detected. 1-Pyrenylsulfate was isolated from mycelial extracts, whereas trans-4,5-dihydro-4,5-dihydroxypyrene was recovered from the culture filtrate. Identification of the compounds was based on their UV spectra, mass spectra, and nuclear magnetic resonance spectra. This is the first report on the detoxification of a polycyclic aromatic hydrocarbon by a plant-inhabiting basidiomycete. The occurrence of 1-pyrenylsulfate and trans-4,5-dihydro-4,5-dihydroxypyrene among fungal metabolites of pyrene is also new.

Journal Article↗

Maple syrup urine disease: clinical, EEG, and plasma amino acid correlations with a theoretical mechanism of acute neurotoxicity.

Classical Maple Syrup Urine Disease (MSUD) is a disease of infancy which is an inherited disorder of metabolism of branched-chain amino acids (BCAA). The BCAA are normally transaminated to branched-chain keto acids (BCKA). However, the enzyme required to metabolize the BCKA is deficient, resulting in elevation of both, the BCAA and the BCKA. One of the BCAA (isoleucine) produces a metabolite that causes the urine to smell like maple syrup. The elevations of the BCAA and BCKA are associated with an acute, critical neurotoxic condition often prior to the age of two weeks. The clinical state, the electroencephalogram-(EEG), and plasma BCAA levels were evaluated in 26 patients with classical and variant MSUD. Patients were seen from the time of diagnosis, often within a week after birth, and some were followed clinically for more than 20 years while on specific diet therapy. They were monitored by plasma BCAA (leucine, isoleucine and valine) levels and a total of 101 EEGs were performed during different phases of their illness. During periods of acute metabolic decompensation, there were marked clinical symptoms of neurotoxicity including opisthotonos, seizures, and coma with elevated BCAA plasma levels. The EEGs revealed spikes, polyspikes, spike-wave complexes, triphasic waves, severe slowing and bursts of periodic suppression. Occasionally paradoxical EEG arousal was noted while the patient was lethargic. During asymptomatic periods when the plasma BCAA were at low or normal levels, EEG abnormalities occurred in patients with and without residual neurological deficit. These observations included rolandic sharp waves (comb-like rhythm) which were observed in 7 of 15 patients less than two months of age. Additionally, paroxysmal spike and spike-wave response to photic stimuli were observed in 9 of 17 patients. Loading tests were performed on three patients. Clinical and EEG changes were most marked after leucine. Less dramatic EEG changes also occurred with the other two BCAA loads but without clinical manifestations. Elevation of the appropriate BCAA plasma level occurred after each load. These studies and a review of the literature suggest that one component of the pathophysiological mechanism for the acute neurotoxic effects in this disorder is related to a defect in glutamate, glutamine and gamma-aminobutyric acid (GABA) production. The BCAAs are transaminated to BCKAs. Further metabolism of the BCKAs are blocked because of enzyme deficiency required for decarboxylation.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗

Outcome for children with medulloblastoma treated with radiation and cisplatin, CCNU, and vincristine chemotherapy.

It has previously been reported in a single-institution trial that progression-free survival of children with medulloblastoma treated with radiotherapy and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), cisplatin, and vincristine chemotherapy during and after radiotherapy was better than the outcome in children treated with radiotherapy alone. To better characterize long-term outcome and duration of disease control, this treatment approach was used for 10 years and expanded to three institutions. Sixty-three children with posterior fossa medulloblastomas were treated with craniospinal local-boost radiotherapy and adjuvant chemotherapy with vincristine weekly during radiotherapy followed by eight 6-week cycles of cisplatin, CCNU, and vincristine. To be eligible for study entry, patients had to be older than 18 months of age at diagnosis and have a subtotal resection, evidence of metastatic disease, and/or brainstem involvement. Patients younger than 5 years of age and without these poor risk factors who received reduced-dose craniospinal radiotherapy (2400 cGy) were also eligible for entry into the study. Sixty-three of 66 eligible patients (95%) were entered and placed on this treatment regimen. Forty-two patients had brainstem involvement, 15 had metastatic disease at the time of diagnosis, and 19 had received a subtotal resection. Progression-free survival for the entire group at 5 years is 85% +/- 6%. Three children have succumbed to a second malignancy, and overall 5-year event-free survival is 83% +/- 6%. Progression-free survival was not adversely affected by younger age at diagnosis, brainstem involvement, or subtotal resection. Five-year actuarial progression-free survival for patients who received reduced-dose radiotherapy was similar to that for patients receiving conventional-dose radiotherapy. Patients with metastatic disease at the time of diagnosis had a 5-year progression-free survival rate of 67% +/- 15%, as compared to 90% +/- 6% for those patients with localized disease at the time of diagnosis (p = 0.037). The authors conclude that overall progression-free survival remains excellent for children with posterior fossa medulloblastomas treated with this drug regimen. Chemotherapy has a definite role in the management of children with medulloblastoma. Further studies are indicated to define which subpopulations of children with medulloblastoma benefit from chemotherapy and what regimens are optimum in increasing disease control and, possibly, in reducing the amount of radiotherapy required.

Adolescent↗

A phase II evaluation of thiotepa in pediatric central nervous system malignancies.

BACKGROUND: Both thiotepa and its active metabolite, tepa, efficiently cross the blood-brain barrier. After intravenous administration, the cerebrospinal fluid concentrations achieved are nearly identical to those in plasma. This provides a strong rationale for testing this agent against brain tumors. METHODS: Sixty pediatric patients with recurrent primary brain tumors were treated on a multiinstitutional Phase II study of intravenous thiotepa at a dose of 65 mg/m2 administered every 3 weeks. This dose is the result of a prior pediatric Phase I trial and is significantly higher than those previously recommended. RESULTS: Three of 13 assessable patients with medulloblastoma had partial responses lasting 22, 25, and 54 weeks. Although no objective responses were observed in 16 assessable patients with malignant gliomas and 14 with brain stem gliomas, 5 of 16 and 4 of 14 patients in these respective strata had prolonged periods of stable disease (SD) lasting from 12 to more than 33 weeks. Nine assessable patients with ependymoma had no objective response, but two had SD, both for more than 33 weeks. Myelosuppression was the principle toxic effect encountered and appeared to be more severe in patients who had received prior craniospinal radiation therapy or nitrosourea therapy. CONCLUSIONS: By conventional Phase II criteria, thiotepa appears to have activity in medulloblastoma. Based on several patients with prolonged SD, it also may possess some limited activity in brain stem and malignant gliomas. The steep in vitro dose-response curve of thiotepa and the long durations of response or SD observed with the dose reported here suggest that moderate-dose to high-dose thiotepa with cytokine support or autologous bone marrow rescue may be associated with an improved response rate to this agent.

Adolescent↗

Genes on chromosomes 4, 9, and 19 involved in 11q23 abnormalities in acute leukemia share sequence homology and/or common motifs.

Chromosome translocations involving band 11q23 are associated with human acute leukemias. These translocations fuse the ALL-1 gene, homolog of Drosophila trithorax and located at chromosome band 11q23, to genes from a variety of chromosomes. We cloned and sequenced cDNAs derived from transcripts of the AF-4 and AF-9 genes involved in the most common chromosome abnormalities, t(4:11)(q21:q23) and t(9:11)(p22:q23), respectively. Sequence analysis indicates high homology between the AF-9 gene protein product and the protein encoded by the ENL gene fused to ALL-1 in (11:19) chromosome translocations. AF-4, AF-9, and ENL proteins contain nuclear targeting sequences as well as serine-rich and proline-rich regions. Stretches abundant in basic amino acids are also present in the three proteins. These results suggest that the different proteins fused to ALL-1 polypeptide(s) provide similar functional domains.

Acute Disease↗

Establishment of a karyotypically normal cytotoxic leukemic T-cell line from a T-ALL sample engrafted in SCID mice.

Bone marrow (BM) cells from a child with an immature (CD3-) acute T lymphoblastic leukemia (T-ALL) bearing no chromosomal abnormalities failed to grow in long-term culture in the presence or absence of recombinant human (rh) growth factors but could be engrafted in severe combined immunodeficient (SCID) mice and induced leukemia. The leukemic cells recovered from the animal tissues could be adapted to grow in vitro in the presence of rh interleukin-2 (IL-2) and give rise to a growth factor-dependent cell line designated TALL-107. This cell line expresses T-cell-specific mature markers (CD2, CD3/T-cell receptor [TCR] alpha beta, CD8, CD56), and its growth can be inhibited by IL-4 of all the cytokines tested. Similar to the original leukemic blasts, TALL-107 cells are clonal, have rearranged TCR-beta, gamma, and delta loci, and a normal 46 XY karyotype. However, unlike the patient's BM cells, the TALL-107 cell line displays potent tumoricidal activity that is not major histocompatibility complex restricted. The magnitude of mRNA expression of perforin and serine esterases and of lytic activity depends on the doses of IL-2 added. TALL-107 cells can also be triggered by CD3- and CD2-specific monoclonal antibodies (MoAbs) to mediate reverse tumor cell lysis. In addition, this cell line produces high levels of interferon gamma and tumor necrosis factor alpha on stimulation with anti-CD3 and/or anti-CD2 MoAb both in the presence or absence of IL-2. The overall data indicate that the SCID mouse is able to support the functional maturation and expansion of a cytotoxic T-cell subset from some types of T-ALL.

Animals↗