A phase I study of cranial radiation therapy with concomitant continuous infusion paclitaxel in children with brain tumors

BACKGROUND

The prognosis of children with high-grade astrocytomas of the central nervous system is grim and has not been substantially improved by conventional chemoradiotherapy. We performed a multi-institutional phase I study to determine the toxicities and tolerance of concurrent external beam radiation of the brain and a unique dose-schedule of paclitaxel as a radiation sensitizer.

PROCEDURE

Paclitaxel was delivered intravenously as a continuous 24 h/day, 7 days/week infusion during the entire 6-week course of fixed schedule standard radiation therapy. The dose of paclitaxel was escalated in patient cohorts in standard phase I design.

RESULTS

Eleven patients (eight brain stem gliomas, one glioblastoma multiforme, and two gliomatosis cerebri) were treated. Dose-limiting toxicity was encountered in the two patients treated at 6 mg/(m(2)/24 h), both of whom developed severe obstipation requiring prolonged hospitalization.

CONCLUSIONS

We have shown in this first study of its kind that paclitaxel can be administered safely to children as a 6-week continuous infusion concurrent with cranial irradiation. The maximally tolerated and recommended phase II dose is 4 mg/(m(2)/day). The benefits of taxanes as clinical radiation sensitizers for children with high-grade gliomas, if any, remain to be determined.

Lack of ETV6 (TEL) gene rearrangements or p16INK4A/p15INK4B homozygous gene deletions in infant acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) occurring in infants less than 1 year of age differs clinically and biologically from that observed in older children. Cytogenetically, 11q23 translocations are detected in approximately 50% of infant ALLs and fuse the 11q23 gene HRX with a variety of partner chromosomal loci. Overall, HRX rearrangements are detected molecularly in 70-80% of infant ALLs as compared to 5-7% of ALLs arising in older children. Two recently described molecular abnormalities in childhood ALL are ETV6 gene rearrangements and homozygous deletions of p16(INK4A) and/or p15(INK4B). Each of these abnormalities occurs in 15-20% of all childhood ALLs, and neither can be accurately identified by routine cytogenetic analyses. The incidence of these genetic abnormalities and their potential relationship to HRX gene status in infant ALL is unknown. Using Southern blot analyses, we determined ETV6 and p16(INK4A)/p15(INK4B) gene status in a cohort of infant ALLs. No ETV6 rearrangements or homozygous deletions (n=69) or homozygous p16(INK4A) and/or p15(INK4B) gene deletions (n=54) were detected in any of the infant ALLs. Therefore, ETV6 and p16(INK4A)/p15(INK4B) do not play a significant role in the pathogenesis of infant ALL, further emphasizing the distinctive biology of this subset of leukemias.

Therapeutic trial for infant acute lymphoblastic leukemia: the Pediatric Oncology Group experience (POG 8493)

PURPOSE

Despite improved event-free survival of older children with acute lymphocytic leukemia (ALL), infants <1 year of age continue to have a very poor prognosis. A new therapy designed specifically for infants with ALL was initiated.

PATIENTS AND METHODS

From 1984 until 1990, 82 eligible infants <1 year of age were entered on a Pediatric Oncology Group (POG) protocol 8493 for infant ALL. Compared to older patients, infants at diagnosis had more overt CNS leukemia (26%), higher initial WBC count (56% >50,000/microl), and a higher likelihood of CD-10 (CALLA) negative lymphoblasts (55%). A translocation involving chromosome 11 at band q23 was detected in 27 of 64 cytogenetically informative cases. Treatment was based upon two institutional pilot studies utilizing chemotherapy doses based upon body weight. Important components included remission induction with cyclophosphamide (Ctx), vincristine (Vcr), cytosine arabinoside (Ara-C), and prednisone (Pred) (COAP); consolidation therapy with teniposide (VM-26) and Ara-C; and continuation therapy with alternating pulses of COAP with VM-26/Ara-C separated by a methotrexate (Mtx) and 6-mercaptopurine (6-MP) backbone plus CNS therapy consisting of standard triple intrathecal therapy (TIT) (Mtx/hydrocortisone/Ara-C), which avoided the use of radiotherapy in this population.

RESULTS

Seventy-six infants achieved a complete remission (93%). Fifty patients have relapsed: 35 isolated marrow relapses, five isolated CNS relapses, eight combined marrow and CNS relapses, and two other relapses. Actuarial event-free survival was 28% (SE = 5%) at 4 years. Infants >274 days (9 months) at diagnosis had a better outcome than those <274 days.

CONCLUSIONS

This study represents a modest outcome improvement in comparison to previous experience with ALL for infants treated on POG trials. More effective therapy is still needed for infants with ALL.

Incidence of childhood and adolescent cancer in Texas

Population-based data from the Texas Cancer Registry were used to describe the incidence of cancer in 1990 among Texas residents younger than 20 years. A total of 788 primary malignant neoplasms were diagnosed. Higher incidence of all cancers was observed among Texas Anglo children compared with Hispanics or African-Americans, and lower rates of central nervous system (CNS) neoplasms were seen among Hispanics. Compared with national data, significantly fewer cases of all cancers combined, non-Hodgkin's lymphoma, neuroblastoma, and CNS neoplasms were seen in Texas Hispanics. The overall incidence of leukemia and acute nonlymphocytic leukemia (ANLL) was highest in Hispanics compared with other Texas children, and a three-fold statistically significant excess of ANLL was evident in Hispanic females compared with national whites. In summary, the incidence of cancer in Texas Hispanic children and adolescents differs from that seen in other racial and ethnic groups. Incidence data for Texas provide additional insight into the descriptive nature of childhood and adolescent cancers.

Ethnicity and cure rates of Texas children with acute lymphoid leukemia

BACKGROUND

Ethnic differences in the survival of children treated for acute lymphoid leukemia (ALL) have been described in several locations. Children of African, Polynesian, Native American, and Mexican ancestry had a less favorable outcome than children of European ancestry when treated in a similar manner by the same physicians and nurses.

METHODS

We reviewed the medical records of the 94 European-American (E-A) and 84 Mexican-American (M-A) Texas children registered and treated in national collaborative ALL therapy trials at the M. D. Anderson Cancer Center in Houston between 1974 and 1985 and followed through June 1994. Information was collected regarding age, sex, presenting clinical features, risk for relapse grouping, protocol assignment, event free survival, and the financial status of their families. Cure was defined as initial continuous complete remission for more than seven years and cessation of therapy for more than four years. Presenting characteristics of E-A and M-A children were compared, and then related to cure rates by univariate and multivariate analyses. Event free survival rates of E-A and M-A children were determined together and by sex.

RESULTS

Comparing presenting features, financial status as identified by pay code was significantly less for M-A children. Other features were not significantly different. By univariate analysis, an age of 2 to 6 years, female sex, initial white blood cell count below 10,000/microL, low risk grouping, registration on the most recent protocol, and full pay status were significantly associated with higher cure rates. By multivariate analysis, male gender, high risk group, and registration on earlier protocols were found to be significantly associated with a low cure rate. Event free survival and cure rate were lower for M-A children, but the differences were not statistically significant.

CONCLUSIONS

Further study of larger numbers of patients, including contemporary immunophenotypic and genotypic characterization of ALL, is needed for better definition of possible ethnic differences. Ethnicity and financial status should be included in the analysis of clinical trials of ALL therapy.

Frequency and prognostic significance of HRX rearrangements in infant acute lymphoblastic leukemia: a Pediatric Oncology Group study

Chromosome band 11q23, the location of the HRX gene, is a site of recurrent translocations in human malignancies. Infants with acute lymphoblastic leukemia (ALL) commonly have 11q23 translocations and have an especially poor prognosis despite intensive chemotherapy. We analyzed 96 cases of infant ALL treated on three consecutive Pediatric Oncology Group protocols to determine the frequency and prognostic significance of molecular rearrangements of HRX. Overall, 78 cases (81%) had HRX rearrangements detected by Southern blot analysis performed with a single HRX cDNA probe, whereas 18 cases (19%) had germline HRX. Of the 78 cases with HRX rearrangements, only 50 had abnormalities of 11q23 detected cytogenetically. Molecular abnormalities of HRX were associated with early treatment failure and a very poor outcome. Estimated event-free survival for patients with HRX rearrangements was 19% (SE, 7%) at 3 years, compared with 46% (SE, 17%) for patients with germline HRX (P = .033 by the two-sided logrank test). Therefore, infants with ALL and molecular abnormalities of HRX represent a group with an extremely high rate of failure who clearly need innovative or experimental treatment. Furthermore, cytogenetic analysis alone failed to detected 36% of HRX rearrangements, suggesting that molecular analysis be performed on all infants with ALL to identify this group of high-risk patients.

Clinical characteristics and treatment outcome of children with acute lymphocytic leukemia and Down's syndrome. A Pediatric Oncology Group study

Of 2947 children with acute lymphocytic leukemia (ALL), treated during three consecutive studies of the Pediatric Oncology Group (1974-1986), 52 (1.8%) had Down's Syndrome (DS). Comparison of clinical and laboratory characteristics showed no significant differences in leukocyte count, racial distribution, sex ratio, platelet count, incidence of mediastinal mass, lymphadenopathy or hepatosplenomegaly, or percentage of blood or bone marrow blasts for children with ALL with or without Down's Syndrome (DS-ALL or NDS-ALL, respectively). However, children with DS-ALL were slightly older at the time of presentation and had higher hemoglobin values. The relative frequency of each major immunophenotype (early pre-B, pre-B, T, or B) was also comparable for patients with or without DS. For this report, treatment regimens were categorized as either conventional (no consolidation therapy) or intensive. Cox regression analysis revealed that the presence of DS, a higher leukocyte count, black race, or age older than 10 years was independently associated with a poorer event-free survival (EFS) for children treated with conventional chemotherapy. However, for the cohort of children who received intensive chemotherapy, DS was no longer an independent risk factor. In fact, event-free survival (EFS) was markedly improved to a level comparable with that observed in the children diagnosed as having NDS-ALL. On the other hand, serious toxicity, requiring interruption of treatment, was significantly more frequent in the intensively treated children with DS compared with similarly treated patients with NDS-ALL, although deaths resulting from toxicity occurred infrequently.

Clinical characteristics and treatment outcome of childhood acute lymphoblastic leukemia with the t(4;11)(q21;q23): a collaborative study of 40 cases

The t(4;11)(q21;q23) chromosomal abnormality was identified in 40 (2%) of 1,986 children with newly diagnosed acute lymphoblastic leukemia (ALL). This translocation was associated with female sex (63%), age less than 1 year (60%), hyperleukocytosis (median leukocyte count, 156.5 x 10(9)/L), CD10-/CD19+ B-precursor cell immunophenotype, and myeloid-associated antigen (CD15) expression (63%). Nearly all cases had at least some CD24- blast cells. The CD10-/CD15%/CD19+/CD24/+ phenotype was found in 20 of the 32 t(4;11) cases tested. None of the 40 cases had the cytogenetic finding of hyperdiploidy greater than 50, which is a favorable prognostic feature. For clinical comparison, the t(4;11) cases were divided into three groups according to age at diagnosis: less than 1 year (n = 24), 1 to 9 years (n = 8), and greater than or equal to 10 years (n = 8). Compared with older patients, infants were more likely to have initial central nervous system leukemia (P = .05) and less likely to have pre-B-cell ALL (P = .05). Complete continuous remission has been maintained in only 7 of 24 infants and 2 of 8 patients aged greater than or equal to 10 years, in contrast to 7 of 8 children in the intermediate age group (P = .048). These findings suggest that the t(4;11) is an adverse prognostic feature in these two age groups.

Factor XIII deficiency and intracranial hemorrhages in infancy

We report an infant with Factor XIII deficiency who had 2 seemingly spontaneous intracranial hemorrhages. It is important to consider Factor XIII deficiency as a possible cause of unexplained intracranial hemorrhages in infancy. Ongoing factor replacement therapy is recommended to prevent further bleeding episodes.

Treatment of systemic fungal infections with liposomal amphotericin B

Forty-six patients with systemic fungal infections were treated with liposomal amphotericin B. Twenty-one patients had disseminated candidiasis, 19 had aspergillosis, and the rest had a variety of other fungal infections. Forty patients failed to respond to conventional amphotericin B therapy, and 6 patients were given liposomal amphotericin B because conventional amphotericin B caused severe side effects. Twenty-four patients had a complete response, and 22 patients failed to respond. No short- or long-term toxic reactions were observed. The acute side effects such as fever, chills, and potassium loss were infrequent and milder than those commonly observed with conventional amphotericin B. No chronic renal, hematologic, or central nervous system side effects were observed. Liposomal amphotericin B therapy was effective and less toxic than conventional amphotericin B therapy.

Aplastic crisis in occult hereditary spherocytosis caused by human parvovirus (HPV B19)

We have reported a case of aplastic crisis occurring in an 11-year-old black boy with occult hereditary spherocytosis. An etiologic diagnosis of human parvovirus (HPV) B19 infection was confirmed serologically. The Coulter Model S + IV proved useful for both diagnosis and treatment monitoring through serial histograms. The relationship of HPV infection and aplastic crisis is discussed.

Neuropsychological effects of childhood cancer treatment

The potential neuropsychological effects of treatment were investigated in 124 childhood cancer patients. Children were classified into groups on the basis of treatment modality and treatment status. All patients received systemic chemotherapy. Other treatment modalities included intrathecal chemotherapy and intrathecal chemotherapy plus central nervous system radiation therapy. Treatment status was determined by whether children were newly diagnosed patients in active treatment or long-term survivors of cancer. This classification resulted in five groups; group 1 (n = 29)--children with newly diagnosed disease who were receiving intrathecal chemotherapy; group 2 (n = 21)--children with newly diagnosed disease who were receiving systemic chemotherapy without central nervous system treatment; group 3 (n = 24)--long-term survivors who had received intrathecal chemotherapy; group 4 (n = 25)--long-term survivors who had received intrathecal chemotherapy plus cranial radiotherapy; and group 5 (n = 25)--long-term survivors who had received systemic chemotherapy only (no specific central nervous system treatment). Groups were compared by using multivariate analysis of variance on sets of neuropsychological test variables that represent major cognitive domains. Results of comparisons indicated significant group differences for most dependent-variable sets. Follow-up pairwise comparisons showed that the group of long-term survivors who had received intrathecal chemotherapy plus cranial radiotherapy consistently obtained lower test scores than the other four groups. These findings are consistent with results of previous studies, thus indicating that intrathecal chemotherapy plus cranial radiotherapy is associated with significant effects on neuropsychological performance. Comparisons among newly diagnosed and long-term groups of patients who did not receive cranial radiotherapy yielded null results on measures of higher-order cognitive functions. However, significant group differences were observed on measures of fine-motor and visual-motor skills; newly diagnosed groups obtained lower scores than the nonirradiated long-term survivor groups. Findings were attributed to chemotherapy-induced peripheral neuropathy that differentially affected the newly diagnosed groups.

Treatment of hepatosplenic candidiasis with liposomal-amphotericin B

Nine patients with hematologic malignancies developed fungal infections, predominantly involving the liver and spleen. Eight patients had biopsy-documented progressive candidiasis and one had an unclassified fungus. The patients were treated with liposomal-amphotericin B (L-AmpB) after their fungal infection progressed during treatment with standard intravenous (IV) AmpB (Fungizone; E. R. Squibb & Son, Princeton, NJ) and/or other antifungals. Eight patients (88.8%) were cured of their fungal infection, and one showed improvement after treatment. Minor acute toxicity and no chronic toxicity were associated with the administration of L-AmpB. L-AmpB is a safe and effective therapeutic method for treating fungal infections that have invaded the liver and spleen even when they are refractory to conventional anti-fungal therapy.

Ag-NOR staining in human chromosomes: differential staining in normal and leukemic bone-marrow samples

A silver staining technique developed by Goodpasture and Bloom (1975) stains a specific protein associated with the activity of ribosomal cistrons during the preceding interphase. By counting the number of chromosomes with darkly stained nucleolus organizer regions (NORs), the number of active NORs per metaphase can be determined. A comparison of NOR activity in bone-marrow cells from leukemic patients in different stages of disease with that of bone marrow from normal, healthy individuals was conducted and differential NOR activity was detected. The control group showed significantly lower NOR activity when compared with a group of patients with acute lymphocytic leukemia (ALL). These preliminary data indicate that this simple cytochemical technique can be effectively used to differentiate between normal and ALL bone-marrow samples.

Diagnostic value of surgical testicular biopsy after therapy for acute lymphocytic leukemia

Inasmuch as several cooperative research groups currently require routine testicular biopsy in boys with acute lymphocytic leukemia before cessation of therapy, we performed bilateral open wedge biopsies in 38 boys aged 4 1/2 to 18 years, all of whom were completing 3 years of therapy, were apparently in complete remission, and had palpably normal testes. Biopsy specimens from two other patients were examined during therapy for specific clinical indications. Among the 40 patients, one biopsy revealed leukemia bilaterally; 39 patients had negative biopsy results, three of whom had overt, biopsy-proved testicular relapse 6 weeks to 17 months after normal biopsy. All four patients with testicular relapse are in complete remission six to 50 months after testicular irradiation. We conclude that random sampling during routine testicular biopsies may fail to demonstrate occult leukemia, and that the high rate of complete remissions following retrieval therapy after overt testicular relapse makes routine biopsies before cessation of therapy unnecessary.

Evaluation of AMSA in children with acute leukemia. A Pediatric Oncology Group study

One hundred four children with advanced leukemia in relapse (74 with acute lymphocytic leukemia [ALL] and 30 with acute nonlymphocytic leukemia [ANLL]) received AMSA (4'-(9-Acridinylamino) methanesulfon -m-anisidide) at a dose of 120 mg/m2/day for 5 days (Regimen I) or 60 mg/m2/day for 10 days (Regimen II). Children with ALL were randomized between Regimens I and II (31 and 36 evaluable patients, respectively). All 29 evaluable patients with ANLL were treated on Regimen I. Eighty-eight percent of evaluable patients experienced severe or life-threatening toxicity, with no statistical differences between Regimens I and II. Bacterial or fungal infections (considered life-threatening or fatal) occurred in 17 children with ALL and in 7 with ANLL. Fatal cardiac toxicity occurred in one patient. Complete or partial response occurred in 25.0% (SE = 8.8%), 28.1% (SE = 8.0%), and 25.9% (SE = 8.4%) of evaluable patients on ALL Regimen I, ALL Regimen II, and ANLL, respectively. However, responses were of short duration (16-91 days). There was no significant difference in the duration of survival from treatment start for the two ALL regimens (P = 0.46). The median duration of survival for ANLL patients was significantly longer (P = 0.004) than that of ALL patients treated on Regimens I and II combined. Eighty-two percent of the complete or partial responses (18 of 22) occurred after the first course of AMSA. At the dose schedules investigated, and in a heavily pretreated patient population, AMSA had activity in childhood leukemia. However, the high incidence of severe, life-threatening, or fatal infections meant that the quality and quantity of responses and survival was not commensurate with the toxicity, and that it would be difficult to incorporate this drug into combination chemotherapy with other myelosuppressive agents.

Mezlocillin pharmacokinetics in pediatric oncology patients

The pharmacokinetics of mezlocillin were studied in 31 children (age, 2 to 19 years) with malignancies and normal renal and hepatic functions. Mezlocillin was administered intravenously over 30 min every 4 h at doses ranging from 12.2 to 125 mg/kg. Blood samples were obtained over one dosage interval at steady state. For all patients, the mean clearance was 0.21 +/- 0.11 liter/h per kg, the mean distribution volume was 0.26 +/- 0.13 liter/kg, and the mean elimination half-life was 0.97 +/- 0.51 h. Trough concentrations were 23.0 +/- 29.9 mg/liter before the dose was administered and 20.4 +/- 27.5 mg/liter at the end of the dosing interval. Peak concentrations averaged 245 +/- 90.4 mg/liter, and average concentrations for the dosing interval were 83.7 +/- 40.4 mg/liter. There were no apparent effects of sex, malignancy, age, or dose on either the kinetic parameters or plasma concentrations. Overall, the disposition parameters for mezlocillin in this patient group were comparable to those reported in adults.

Antimicrobial therapy of febrile children with malignancies and possible sepsis

A prospective study of 100 pediatric patients (2 months to 17 years of age) who had malignancies and fever was conducted. Gentamicin or netilmicin and a beta-lactam antibiotic were administered as initial empiric treatment. Before therapy profound granulocytopenia (fewer than 500 polymorphonuclear leukocytes/microliter) was present in 66% of children and persisted to the end of therapy in 42% of children. Of the 40 children with microbiologically documented infections, 38 (95%) responded to therapy. The aminoglycoside dosing regimen of 2 mg/kg/dose intravenously over 60 minutes every 6 hours produced antibiotic concentrations in serum of 5.8 +/- 0.3 microgram/ml at the end of the infusion in the netilmicin group and 1.5 +/- 0.1 microgram/ml 6 hours after the infusion and of 6.2 +/- 0.2 and 0.9 +/- 0.1 microgram/ml for the two time periods in the gentamicin group. The serum half-lives, volumes of distribution and the total body clearance rates were comparable for netilmicin and gentamicin. No accumulation of netilmicin or gentamicin was noted. Seven patients had renal compromise, five before institution of antibiotic therapy and two while on therapy. Four episodes of ototoxicity were not related to antibiotic therapy. Superinfection occurred in five children. The combination of either gentamicin or netilmicin with a beta-lactam antibiotic produced excellent results for episodes of fever in neutropenic children with cancer. In children with severe underlying disease and/or granulocytopenia, antibiotic combinations have achieved an optimal efficacy. Future emphasis should be placed on prevention, immunoregulation and nonbacterial pathogens.

High-dose methotrexate as part of remission maintenance therapy for childhood acute lymphocytic leukemia: a Pediatric Oncology Group pilot study

Seventeen children with acute lymphocytic leukemia (ALL) in remission were treated with parenteral high-dose methotrexate (HDM) pulses every eight weeks during standard 6-mercaptopurine and methotrexate (MTX) oral maintenance therapy. MTX (1,000 mg/m2) was infused over one hour followed by one hour of intravenous hydration for the purpose of achieving plasma and cerebrospinal fluid (CSF) levels greater than 10(-6) M for a period of 24 hours. Leucovorin (15 mg/m2) was administered orally six, 12, and 18 hours after completion of the HDM. Plasma and CSF concentrations of MTX were evaluated serially in the first 48 hours. During the first 24 hours, the plasma MTX level was maintained at greater than 10(-6) M. The patients receiving intrathecal MTX at a dose of 15 mg/m2 had an adequate, sustained MTX level in the CSF, but when no intrathecal MTX was administered, the CSF levels were less than 10(-6) M. For that reason, intrathecal MTX in a low dose (6 mg/m2) was injected intrathecally one hour after the HDM infusion, allowing the MTX level in CSF to approximate 10(-6) M over the 24 hours. The toxicity of this therapy was minimal. Due to the facts that the plasma and CSF MTX levels could be sustained above the desired concentrations and this regimen could be given in the outpatient clinic, this program has been incorporated into an ongoing study in an effort to prolong complete remissions.

Pelvic and ovarian extramedullary leukemic relapse in young girls: a report of four cases and review of the literature

Currently attention is focused on the testicle as a site of leukemic relapse. Leukemic involvement of the ovary has been described in several autopsy series with an incidence of 11-50% in patients with bone marrow relapse, but has rarely been reported during the clinical course of leukemia. In this report, four girls with childhood acute lymphocyte leukemia (ALL) who relapsed with a pelvic mass are presented. Three had marked ovarian infiltrates and the fourth had a presacral mass without ovarian disease. Involvement was also present in abdominal and pelvic lymph nodes, mesentery, omentum, and serosal surfaces. Two patients had infiltrates of the fallopian tubes and one had uterine involvement. Two patients had central nervous system disease and one patient has renal involvement at the time of relapse. Relapse occurred late in the course of disease. All patients had been in complete continuous remission prior to relapse. Retreatment was instituted in all patients and follow-up ranges from 18-135 months from the time of pelvic relapse. All patients have maintained continuous bone marrow remission from the time of initial diagnosis, and one patient died 18 months after ovarian relapse with significant extramedullary disease but no marrow involvement. This represents the first series of pelvic extramedullary leukemic relapse in females, an area of involvement that may be encountered more frequently in the future.

Bioavailability of allopurinol oral and rectal dosage forms

The bioavailability of allopurinol from orally administered tablets and rectally administered suppositories is reported. Two types of rectal suppositories (cocoa butter and polyethylene glycol) were compounded and contained 300 mg allopurinol (from oral tablets). Five healthy volunteers received 300 mg allopurinol orally from tablets or rectally from suppositories in a randomized, three-way crossover design. Serial blood samples were drawn for 72 hours following administration and were analyzed by high-pressure liquid chromatography for allopurinol and its metabolite, oxipurinol. The interaction between allopurinol and PEG was studied in vitro using a dialysis method. Serum allopurinol levels following oral administration of tablets peaked at 1.5 +/- 0.23 microgram/ml at 5.20 +/- 0.65 hours. Allopurinol was not detectable after administration of cocoa butter/allopurinol suppositories; oxipurinol peaked at 0.34 +/- 0.14 microgram/ml at 13 +/- 11 hours. The bioavailability of allopurinol from the cocoa butter suppository, relative to the tablet, was 5.77 +/- 2.5%. Neither allopurinol nor oxipurinol was detectable (less than 0.1 microgram/ml) in the sera of persons following administration of PEG suppositories. Dialysis studies showed decreased loss of allopurinol from the dialysis sac as PEG concentration increased. The rectal suppositories of allopurinol used in this study did not appear to be an efficient means of administering this drug.

Systemic mycosis due to Trichosporon cutaneum: a report of two additional cases

Two additional cases of systemic mycosis due to Trichosporon cutaneum are reported and are compared with the previously published case of Rivera and Cangir. Both patients (a four-year-old male and a 57-year-old female) had acute leukemia for which they were receiving chemotherapy, and both presented with fever that was unresponsive to conventional antibiotics. Both had positive blood cultures for Trichosporon cutaneum. The disease was further documented in the four-year-old male by renal biopsy and by bone marrow culture; he was treated with apparent success with amphotericin B. However, the 57-year-old female died shortly after the begining of similar treatment, and autopsy demonstrated involvement of the left kidney, spleen, bone marrow, and liver. The organism in both these cases, as well as the case of Rivera and Cangir, exhibited both hyphal and yeastlike forms in tissue sections. We believe that the therapeutic success in the case of the four-year-old male was primarily related to his remission from leukemia.

Amikacin pharmacokinetics in pediatric patients with malignancy

The pharmacokinetics of amikacin were evaluated in 50 pediatric patients (1 to 17 years of age) with malignancies and normal renal function. Dosage regimens of 5 mg/kg per dose were administered intravenously (i) over 30 min every 8 h, (ii) over 60 min every 8 h, and (iii) over 60 min every 6 h. Administration of amikacin over 30 min produced concentrations in serum of 29.3 +/- 5.7 micrograms/ml at the end of the infusion and subtherapeutic concentrations 4 h after the infusion. The regimen of 20 mg/kg per 24 h, divided into doses given every 6 h infused over 60 min, achieved concentrations in serum at the end of the infusion of 17.2 +/- 1.7 micrograms/ml and at 6 h of 1.2 +/- 0.3 microgram/ml. The serum half-life was 1.24 +/- 0.09 h, volume of distribution was 0.26 +/- 0.02 liter/kg, and total body clearance rate was 131 +/- 10 ml/min per 1.73 m2. No accumulation of amikacin was noted, and no significant side effects could be attributed to the drug. This study suggests that the optimal initial dosage regimen of amikacin in children is 20 mg/kg per 24 h administered in equal doses every 6 h over 60 min; however, optimal therapy requires individualization of dosage based on measured serum concentrations and susceptibility data on bacterial pathogens isolated.

Multiple-dose amikacin kinetics in pediatric oncology patients

Amikacin kinetics was studied in 8 pediatric oncology patients who received the drug by intravenous infusion over 30 or 60 min at a dose of 5 mg/kg every 6 or 8 hr. This regimen is recommended but, due to patient variability, patients should be monitored. Dosing intervals during 1 or 2 and 3 or 4 days of therapy were studied with serum samples collected before and at the end of the infusion and serially to the end of the dosing interval. The data appeared consistent with and were analyzed according to 1-compartment model. An equation describing serum concentration with time for the multiple-dose case was fit to each patient's multiple-interval data with nonlinear regression. Half-life averaged 1.2 hr. volume of distribution 0.24 l/kg, and total body clearance 109 ml/min/1.73 m2 or 2.51 ml/min/kg. The volume of distribution and the clearance are greater than reported for adults and probably account for the larger dose needed to achieve and maintain therapeutic levels. Although the total daily dose was greater than previously reported, there were no signs of toxicity, although therapuetic concentrations were maintained.

Soft tissue ameloblastoma in a 92-year-old woman

Ameloblastoma is a rare epithelial neoplasm that most commonly is found within the bony structure of the jaw. Soft tissue ameloblastomas are rarer. Only nine well-documented cases are found in the reviewed world's literature. It is our purpose to report the clinical and morphological features of a gingival ameloblastoma in a 92-year-old woman.

Preferential solvation of Co2+ and Ni2+ ions in mixed solvents: n.m.r. methods

A method for the study of preferential solvation in the outer coordination spheres from paramagnetic broadening of solvent proton n.m.r. signals was proposed by Frankel, Stengle, and Langford. It is now extended to determinations of the relative concentrations of water and dioxane, dimethylformamide, or dimethylsulfoxide in the inner coordination spheres of Co2+ and Ni2+ ions in the binary solvent mixtures. The assumptions of the analysis are cross-checked by a new method based on the contact shifts experienced by protons on solvent molecules in the coordination spheres of paramagnetic ions. The second method depends upon assumptions independent of the first. Three cases are presented as tests of these n.m.r. approaches. It is clear that highly precise solvation sphere populations will be difficult to obtain but that useful and significant information can be obtained in situations to which alternative methods are almost totally inapplicable.The results indicate that dimethylsulfoxide and dimethylformamide are good competitors for coordination sites but that dioxane is excluded by water.