Genomic gains and losses influence expression levels of genes located within the affected regions: a study on acute myeloid leukemias with trisomy 8, 11, or 13, monosomy 7, or deletion 5q

We performed microarray analyses in AML with trisomies 8 (n=12), 11 (n=7), 13 (n=7), monosomy 7 (n=9), and deletion 5q (n=7) as sole changes to investigate whether genomic gains and losses translate into altered expression levels of genes located in the affected chromosomal regions. Controls were 104 AML with normal karyotype. In subgroups with trisomy, the median expression of genes located on gained chromosomes was higher, while in AML with monosomy 7 and deletion 5q the median expression of genes located in deleted regions was lower. The 50 most differentially expressed genes, as compared to all other subtypes, were equally distributed over the genome in AML subgroups with trisomies. In contrast, 30 and 86% of the most differentially expressed genes characteristic for AML with 5q deletion and monosomy 7 are located on chromosomes 5 or 7. In conclusion, gain of whole chromosomes leads to overexpression of genes located on the respective chromosomes. Losses of larger regions of the genome translate into lower expression of the majority of genes represented by only one allele. The reduced expression of these genes is the most characteristic difference in gene expression profiles between AML with monosomy 7 and AML with deletion 5q, respectively, and other AML subtypes. Therefore, these data provide evidence that gene dosage effects gene expression in AML with unbalanced karyotype abnormalities. Losses of specific regions of the genome determine the gene expression profile more strongly than the gain of whole chromosomes.

A comparative study of polymerization lamps to determine the degree of cure of composites using infrared spectroscopy

The aim of this study was to compare polymerization lamps of various technologies (halogen, high performance halogen, xenon, i.e. plasma arc, as well as diode lamps) to determine the degree of polymerization of composite probes using Fourier-transform infrared (FTIR) spectroscopy. To observe the light-induced curing reaction under a bracket, an attenuated total reflection (ATR)-FTIR was used. The results showed that the recommended curing times for all the polymerization lamps tested were adequate for successful polymerization of the composite used (degree of conversion approximately 60 per cent, which did not exceed 66 per cent after longer curing times). However, even after very long curing times, delayed curing of the composite must be taken into consideration as there was a decrease of approximately 10 per cent in FTIR band intensities (1637 and 3104 cm(-1)). ATR-FTIR spectroscopy showed that when bonding brackets with materials cured by light, uncured areas remain in the centre of the lowest layer of the adhesive.

Determination of Residual Vulcanization Accelerators in Natural Rubber Latex Films Using FTIR Spectroscopy

Many vulcanization accelerators are well known contact sensitizers (Type IV allergy) and therefore pose a serious problem in latex applications like gloves and condoms. In this study, a vulcanization system for NR latex based on diisopropylxanthogen polysulfide (DiPXP) and Zn-diisononyl dithiocarbamate (ZDiNC) was investigated. The thermal decomposition of DiPXP during and after the vulcanization process was assessed. FTIR methods for the determination of residual vulcanization accelerators ZDiNC and DiPXP in latex films and extracts therefrom were developed. When appropriate conditions are selected for the production of NR latex films, the accelerator DiPXP was no more detectable in extracts from the finished NR latex product. The use of thermally decomposable vulcanization accelerators is a way towards NR latex products with significantly reduced allergenic potential.

Differential adaptation of neurocognitive brain functions to recurrent hypoglycemia in healthy men

Antecedent hypoglycemia is known to attenuate hormonal and symptomatic responses to subsequent hypoglycemia. Whether this pertains also to hypoglycemia-induced cognitive dysfunction is controversially discussed. Neurocognitive adaptation might essentially depend on the type of function. Here, we compared the influence of recurrent hypoglycemia in 15 healthy men on counterregulatory hormones, subjective symptoms of hypoglycemia, short-term memory performance (word recall), and performance on an auditory attention task (oddball). The attention task was also used to record event-related brain potential (ERP) indicators of stimulus processing. In each subject, three consecutive hypoglycemic clamps were performed, two on day 1 and the third on day 2. Neurocognitive testing was performed during baseline and at two different hypoglycemic plateaus (2.8 and 2.5 mmol/l) during the first and last clamp. As expected, hormonal responses were significantly reduced to the last as compared to the first hypoglycemia indicating adaptation. Subjective symptoms also decreased in response to recurrent hypoglycemia. Short-term memory performance deteriorated distinctly on the first hypoglycemic clamp, but maintained the normal level on the last clamp (P=0.006). Likewise, the impairment in reaction time (P=0.022) and response accuracy (P=0.005) was distinctly smaller on the last than first hypoglycemia. In parallel, the hypoglycemia-induced decrease in P3 amplitude (P=0.019) and the increase in P3 latency (P=0.049) were diminished with recurrent hypoglycemia, indicating that late stages of controlled stimulus processing likewise adapted. In contrast, the distinct decrease in amplitudes of the N1 and P2 components of the ERP (preceding the P3) was closely comparable in response to the first and last hypoglycemia (P>0.3). Together results indicate an adaptation to recurrent hypoglycemia for signs of controlled stimulus processing presumably involving hippocampo-prefrontocortical circuitry, while earlier automatic stages of processing appear to be spared.

Exotic meson decay to omegapi0pi-

A partial-wave analysis of the mesons from the reaction pi(-)p --> pi(+)pi(-)pi(-)pi(0)pi(0)p has been performed. The data show b(1)pi decay of the spin-exotic states pi(1)(1600) and pi(1)(2000). Three isovector 2(-+) states were seen in the omegarho(-) decay channel. In addition to the well known pi(2)(1670), signals were also observed for pi(2)(1880) and pi(2)(1970).

Spectral encoding of the polarization state of light in multiplexed polarization-sensitive lasing structures

We report the experimental demonstration of spectral encoding of the polarization state of light by use of multiplexed distributed-feedback lasers in a dye-doped organic thin film by exploiting the pump polarization selectivity of the superimposed resonators. Measurement of the Stokes parameters of the pump light without a priori knowledge of the lasing properties of the structure is discussed.

Discrimination of chronic lymphocytic leukemia (CLL) and CLL/PL by cytomorphology can clearly be correlated to specific genetic markers as investigated by interphase fluorescence in situ hybridization (FISH)

Although interphase fluorescence in situ hybridization (FISH) is routinely used in chronic lymphocytic leukemia (CLL), differences in the chromosomal pattern with respect to morphological subtypes of CLL (typical CLL, CLL/PL, PLL) are still under debate. We studied 153 patients with CLL and correlated cytomorphology on peripheral blood stains with FISH analysis and other prognostic markers. The percentage of prolymphocytes was calculated as a continuous variable and followed published thresholds in parallel while being correlated to FISH analysis. Higher percentages of prolymphocytes were associated significantly with deletion of 17p13. Deletion of 17p13 was most frequently observed in patients with more than 30% prolymphocytes. Trisomy 12 was found mainly in cases with 6-30% prolymphocytes. The percentage of prolymphocytes did not correlate with deletions of 11q23 or with 13q14 abnormalities. In conclusion, we suggest that further research focus on the percentage of prolymphocytes in CLL. Doing so, biologically relevant thresholds for the percentages of prolymphocytes in the peripheral blood and their association to underlying genetic markers could be investigated together with other biologically and especially prognostic markers.

Traitement antibiotique oral des neutropénies fébriles en onco-hématologie

THE CONTEXT: Up until the nineties, the intravenous administration of a broad spectrum antibiotic was the classical treatment of any patient presenting with febrile neutropenia. Since then, in patients considered at low risk and with expected of neutropenia less than 7-10 days, oral antibiotherapy has become an attractive option. TWO LARGE STUDIES: A study by the antimicrobial group of the EORTC (European organisation for research and treatment of cancer) and a North American study have compared the efficacy of an oral combination of ciprofloxacine and amoxicillin/clavulanic acid with that of an intravenous antibiotherapy in low-risk patients presenting febrile neutropenia. In both studies, the success rate was the same in the group of patients treated with oral antibiotics and those treated with intravenous antibiotics. RESERVATIONS: These two studies were conducted in hospitalised patients. No conclusions can be drawn with regard to out-patient treatment. Out-patient management would only be possible after appropriate selection of patients at low risk.

Karyotype is an independent prognostic parameter in therapy-related acute myeloid leukemia (t-AML): an analysis of 93 patients with t-AML in comparison to 1091 patients with de novo AML

The aim of this study was to compare the pattern of karyotype abnormalities of therapy-related acute myeloid leukemia (t-AML) (n=93) with de novo AML (n=1091), and to evaluate their impact on prognosis. Favorable, intermediate, and unfavorable cytogenetics were observed in 25.8, 28.0, and 46.2% of t-AML, and in 22.2, 57.3, and 20.4% of de novo AML. The median overall survival (OS) was shorter in t-AML than in de novo AML (10 vs 15 months, P=0.0007). Favorable and unfavorable cytogenetics had a prognostic impact with respect to OS in both t-AML (P=0.001 and 0.0001) and de novo AML (P<0.0001 and <0.0001). To define the overall prognostic impact of cytogenetics and t-AML, a multivariate Cox's regression analysis was performed for OS with favorable cytogenetics, unfavorable cytogenetics, t-AML, age, and white blood cell (WBC) count as covariates. All parameters proved to be independently related to OS (P=0.001 for t-AML, P<0.0001 for all other parameters). Within patients with t-AML, there were significant correlations between OS and both unfavorable (P<0.0001) and favorable cytogenetics (P=0.001), while age and WBC count had no impact on OS. In conclusion, these data indicate that cytogenetics are an important prognostic parameter in t-AML. Furthermore, t-AML is an unfavorable factor independent of cytogenetics with respect to survival.

All-optical tunability of holographically multiplexed organic distributed feedback lasers

We report the fabrication and characterization of optically pumped multiple grating distributed feedback lasers in dye doped organic thin films. Each multiplexed laser structure is inscribed at a different angle in the sample plane and possesses a unique emission wavelength. The polarization sensitivity of these structures with respect to the pumping light is exploited to enable simple and high-speed switching of the device emission wavelength.

Pediatric acute lymphoblastic leukemia (ALL) gene expression signatures classify an independent cohort of adult ALL patients

Recent reports support a possible future application of gene expression profiling for the diagnosis of leukemias. However, the robustness of subtype-specific gene expression signatures has to be proven on independent patient samples. Here, we present gene expression data of 34 adult acute lymphoblastic leukemia (ALL) patients (Affymetrix U133A microarrays). Support Vector Machines (SVMs) were applied to stratify our samples based on given gene lists reported to predict MLL, BCR-ABL, and T-ALL, as well as MLL and non-MLL gene rearrangement positive pediatric ALL. In addition, seven other B-precursor ALL cases not bearing t(9;22) or t(11q23)/MLL chromosomal aberrations were analyzed. Using top differentially expressed genes, hierarchical cluster and principal component analyses demonstrate that the genetically more heterogeneous B-precursor ALL samples intercalate with BCR-ABL-positive cases, but were clearly distinct from T-ALL and MLL profiles. Similar expression signatures were observed for both heterogeneous B-precursor ALL and for BCR-ABL-positive cases. As an unrelated laboratory, we demonstrate that gene signatures defined for childhood ALL were also capable of stratifying distinct subtypes in our cohort of adult ALL patients. As such, previously reported gene expression patterns identified by microarray technology are validated and confirmed on truly independent leukemia patient samples.

New insights into the biology of acute myeloid leukemia and their impact on treatment

Acute myeloid leukemia (AML) is a heterogeneous group of disorders that can be discriminated by morphology, immunophenotyping or more recently by cytogenetic and molecular techniques. By cytogenetics two major groups of AML can be discriminated: One group with detectable chromosomal aberrations accounting for approximately 52 % of all de novo AML and the second group without cytogenetically detectable karyotype abnormalities. In the first group two major subtypes can be further distinguished. The first group comprises AML with balanced aberrations mainly consisting in t(8;21), t(15;17) and inv(16). The second group comprizes cases with unbalanced aberrations including particularly 5q-, 17q- -5 and AML with complex karyotypes. AMLs with balanced aberrations have a good prognosis with long term survival being achieved in approximately 60 %-80 % of cases. AMLs with non-balanced aberrations on the other hand have a poor prognosis with only 10 %-15 % long-term survivors. AMLs with no detectable abnormalities or other cytogenetic aberrations comprise a group with an intermediate prognosis in which long term survival is achieved in approximately 25 %-30 % of cases. Biologically, AMLs with balanced aberrations regularly involve the deregulation of transcription factors resulting in an impairment of cell differentiation and proliferation. AMLs with unbalanced aberrations are mostly characterized by a loss of genetic material resulting in an alteration of cell cycle control and DNA repair. A new view on the biology of AML has recently been made possible through the analysis of gene expression profiles. This technique is still under investigation. First results, however, already show that gene expression patterns have a high diagnostic potential and allow to detect biology subgroups with a high accuracy. Furthermore, by this technique pathways can be identified that are altered in the leukemic process. Gene expression profiling therefore opens a new and exciting perspective in leukemia biology and therapy that may have substantial impact on the improvement of diagnosis and more importantly may guide therapeutic strategies.

Karyotype instability between diagnosis and relapse in 117 patients with acute myeloid leukemia: implications for resistance against therapy

The instability of the karyotype may play a role in the development of refractoriness of acute myeloid leukemia (AML) to anti-leukemic therapy. Therefore, in the current study cytogenetic analyses were performed in 117 patients with AML both at diagnosis and at relapse. Changes in karyotype were observed in 38% (36% of initially normal karyotypes, 39% of initially aberrant karyotypes). An evolution of karyotype, ie the acquisition of further aberrations in addition to those present at diagnosis, occurred more frequently in patients with unfavorable karyotypes at diagnosis as compared to all others (60% vs 32%, P = 0.0095). The duration from initial diagnosis to relapse was significantly shorter in cases with an evolution of the aberrant karyotype as compared to cases with no changes in the aberrant karyotype between diagnosis and relapse or with solely regression of aberrations at relapse (9.2 +/- 4.4 vs14.0 +/- 8.5 months, P = 0.0081). In an additional analysis, another cohort of 120 patients with refractory and relapsed AML who were treated uniformly within the respective trial of the German AML Cooperative Group was analyzed cytogenetically at diagnosis and at relapse to further prove the prognostic impact of karyotype aberrations at relapse. Karyotypes were prognostically favorable, intermediate, unfavorable and not available in 8%, 50%, 17% and 25% at diagnosis and in 8%, 49%, 21% and 22% at relapse, respectively. Karyotype aberrations at diagnosis had no impact on response to therapy (P = 0.32) but influenced survival and event-free survival significantly (P = 0.03 and P = 0.02). In contrast, karyotype aberrations at relapse strongly influenced response to therapy (P = 0.05), survival (P = 0.01), and event-free survival (P = 0.002). These data suggest that the instability of the karyotype between diagnosis and relapse and thus karyotype aberrations at relapse in particular contribute to the refractoriness of AML to anti-leukemic therapy.

The effect of experimentally induced insulin resistance on the leptin response to hyperinsulinaemia

OBJECTIVE

Insulin is thought to be an important regulator of leptin secretion. However, increasing evidence suggests that insulin-mediated glucose uptake rather than insulin per se regulates circulating leptin concentration. Here, we hypothesised that a reduction of insulin sensitivity, ie insulin resistance, will diminish the stimulatory effect of insulin on leptin secretion as a consequence of decreased insulin-mediated glucose uptake.

DESIGN

Changes in serum leptin concentration during 30 hyperinsulinaemic-hypoglycaemic clamps were studied after induction of different levels of insulin resistance in normal-weight men. In 15 subjects insulin sensitivity was reduced by exposing them to a 2.5 h antecedent hypoglycaemia (3.1 mmol/l) induced by a high rate of insulin infusion (15.0 mU/min/kg) on the day before the proper experiment ('ante-hypo' condition). In the other 15 subjects no antecedent hypoglycaemia was induced ('control' condition). The proper experiment on both conditions was a 6 h stepwise hypoglycaemic clamp induced by a constant rate of insulin infusion (1.5 mU/min/kg).

SUBJECTS

Experiments were carried out in 30 lean healthy subjects (age, mean +/- s.e.m., 26 +/- 1 y; body mass index, 23.1 +/- 0.6 kg/m2).

RESULTS

As expected, glucose demand during the clamp was lower in the ante-hypo condition than in the control condition (gram of glucose infused per kilogram body weight, 1.52 +/- 0.16 vs 2.01 +/- 0.17 g/kg; P < 0.05). During the clamp, leptin levels increased by 25.4 +/- 4.3% in the control condition (P < 0.05), but not in the ante-hypo condition (+4.8 +/- 4.5%; P > 0.25). Thus, serum leptin response to the clamp significantly differed between the two conditions (P < 0.01). Across both conditions, the increase of leptin levels during the clamp was correlated with the amount of glucose infused (r = 0.37; P < 0.05).

CONCLUSION

Considering that insulin concentrations were identical during both clamp conditions, the data indicate that experimentally-induced insulin resistance diminishes the stimulatory effect of insulin on leptin secretion.

Hypoglycemia, but not insulin, acutely decreases LH and T secretion in men

Hypoandrogenemia is frequently associated with hyperinsulinemia in men with the metabolic syndrome. We questioned whether insulin or changes in blood glucose levels influence pituitary gonadotropin secretion or testicular steroidogenesis in healthy men. Also, the relationship between hypoglycemia-induced activation of the hypothalamus-pituitary-adrenal axis and altered steroidogenesis was examined. Euglycemic and hypoglycemic clamp experiments were performed in 30 healthy men over a period of 6 h. Half of the men were infused with insulin at a rate of 1.5 mU/min.kg; the other half were infused at a rate of 15.0 mU/min.kg. Plasma glucose was held constant during a euglycemic clamp session and was decreased stepwise in a hypoglycemic clamp session. LH and total/free T concentrations decreased under hypoglycemic conditions regardless of the rate of insulin infusion. With euglycemic conditions, LH and T levels remained unchanged. Dehydroepiandrosterone concentrations increased during hypoglycemia, but not during the euglycemic conditions. The FSH concentration was not affected by insulin or glycemic clamps. Hypoglycemia acutely suppresses T secretion, and this effect is apparently mediated by pituitary LH. Insulin is ineffective. As counterregulation to hypoglycemia begins at normoglycemic ranges in poorly controlled type 2 diabetes and probably also in patients with long-term perturbed glucose regulation in the metabolic syndrome, control of glucose-responsive neurons in the brain may contribute to hypoandrogenemia. Apart from down-regulation of hypothalamic release of GnRH, concurrent activation of the pituitary-adrenal axis (i.e. increased release of dehydroepiandrosterone) may add to the suppressive effect of hypoglycemia on gonadal steroidogenesis.

Improving influence of insulin on cognitive functions in humans

Insulin receptors have been identified in limbic brain structures, but their functional relevance is still unclear. In order to characterize some of their effects, we evaluated auditory evoked brain potentials (AEP) in a vigilance task, behavioral measures of memory (recall of words) and selective attention (Stroop test) during infusion of insulin. The hormone was infused at two different rates (1.5 mU/kg x min, "low insulin", and 15 mU/kg x min, "high insulin"), inducing respectively serum levels of 543 +/- 34 and 24,029 +/- 1,595 pmol/l. This experimental design allowed to compare cognitive parameters under two conditions presenting markedly different insulin levels, but with minimal incidence on blood glucose concentrations since these were kept constant by glucose infusion. A "no insulin treatment" group was not included in order to avoid leaving patients infused with glucose without insulin treatment. Measures were taken during a baseline phase preceding insulin infusion and every 90 min during the 360 min of insulin infusion. Compared with "low insulin", "high insulin" induced a slow negative potential shift in the AEP over the frontal cortex (average amplitude, high insulin: 0.27 +/- 0.48 microV; low insulin: 1.87 +/- 0.48 microV, p < 0.005), which was paralleled by enhanced memory performance (words recalled, high insulin: 22.04 +/- 0.93; low insulin: 19.29 +/- 0.92, p < 0.05). Also, during "high insulin" subjects displayed enhanced performance on the Stroop test (p < 0.05) and expressed less difficulty in thinking than during "low insulin" (p < 0.03). Results indicate an improving effect of insulin on cognitive function, and may provide a frame for further investigations of neurobehavioral effects of insulin in patients with lowered or enhanced brain insulin, i.e., patients with Alzheimer's disease or diabetes mellitus.

Losartan attenuates symptomatic and hormonal responses to hypoglycemia in humans

OBJECTIVE

Reduced awareness of hypoglycemic symptoms and compromised hormonal counterregulation increase the risk of severe hypoglycemia in people with diabetes mellitus. Up to the present, angiotensin 1 receptor blockers, which play an important role in controlling diabetic complications, have not been known to increase the risk of hypoglycemia. Nevertheless, we observed 3 cases of diabetic patients complaining of reduced awareness of hypoglycemic symptoms while they were under treatment with losartan in our outpatients clinic. We therefore investigated the effects of losartan on symptomatic and hormonal responses to hypoglycemia in humans.

RESEARCH DESIGN AND METHODS

We carried out a randomized, double-blind, crossover study including 16 healthy men. The subjects received losartan 50 mg/d versus placebo. Treatment periods lasted for 7 days and were followed by a stepwise hypoglycemic clamp session (4.5 to 3.8 to 3.1 to 2.4 mmol/L) with measurement of counterregulatory hormones (epinephrine, norepinephrine, adrenocorticotropin, cortisol, glucagon), symptoms, and hemodynamic parameters (blood pressure, heart rate).

RESULTS

Losartan attenuated the hypoglycemia-induced rise in plasma epinephrine (6480 +/- 490 pmol/L versus placebo 8970 +/- 790 pmol/L; P <.001) and the rise in plasma adrenocorticotropin (21 +/- 2 pmol/L versus 26 +/- 3 pmol/L; P <.01). Losartan also reduced symptom scores during hypoglycemia (P <.05).

CONCLUSION

We conclude that short-term treatment with losartan slightly attenuates symptomatic and hormonal responses to hypoglycemia. At present, for patients who are unaware of hypoglycemia and who require antihypertensive or nephroprotective treatment, we would recommend caution concerning treatment with losartan.

Fatigue and hyponatremia in a 75-year-old woman: unusual presentation of hypophysitis

A 75-year-old woman presented with general fatigue progressing to somnolence. Laboratory tests showed marked hyponatremia. TSH in the normal range, but low levels of free T3 and free T4. Evaluation of pituitary hormones and magnetic resonance imaging of the pituitary unmasked findings characteristic for hypophysitis with secondary adrenal insufficiency and secondary hypothyroidism. Hormonal substitution with hydrocortisone and levothyroxine resulted in rapid improvement of all symptoms and signs. Without additional treatment shrinkage of the pituitary gland could be documented. Our report extends the known clinical and pathological spectrum of hypophysitis and illustrates the need to include this uncommon entity in the differential diagnosis of hyponatremia even in elderly patients.

Metformin does not adversely affect hormonal and symptomatic responses to recurrent hypoglycemia

Body weight gain and severe hypoglycemia are the major adverse effects of insulin therapy in type 2 diabetic patients. Metformin has been shown to prevent insulin therapy-induced body weight gain when used in combination with insulin. However, the effects of metformin on hormonal and symptomatic responses to hypoglycemia mediating hypoglycemia awareness have not been assessed to date. Fifteen young healthy men were treated with 850 mg metformin and placebo twice daily for a 16-d period in a double blind, cross-over design. On the last 2 d of the treatment period, the subjects underwent three hypoglycemic clamp experiments, with the first and the last performed with identical patterns of plasma glucose decrease. Differences between the effects of metformin and placebo (effect of metformin) as well as between first and last hypoglycemic clamps (effect of antecedent hypoglycemia) were assessed. Antecedent hypoglycemia significantly reduced epinephrine, ACTH, cortisol, glucagon, GH, and symptomatic responses to hypoglycemia (P < 0.05 for all variables). There was no detectable effect of metformin on epinephrine, norepinephrine, ACTH, cortisol, glucagon, or autonomic symptomatic response to hypoglycemia (P > 0.05 for all comparisons), except that metformin slightly increased the response of GH to hypoglycemia (P = 0.039). The latter finding may be due to an IGF-I-reducing effect of metformin, as after 14 d of metformin treatment baseline levels of IGF-I were significantly lower than in the placebo condition (236.9 +/- 13.9 vs. 263.2 +/- 14.4 microg/liter; P = 0.015). The data indicate that metformin does not adversely affect hormonal and symptomatic responses to hypoglycemia. This finding appears to be relevant with regard to the safety of the combination of metformin with insulin therapy.

Pharmacokinetics of cisplatin and relation to nephrotoxicity in paediatric patients

BACKGROUND

Cisplatin is a highly effective and frequently used drug in the chemotherapy of solid tumours in children, but only limited data are available on the pharmacokinetics of cisplatin and its associated nephrotoxicity in paediatric patients.

METHODS

We investigated the pharmacokinetics of free platinum (Pt) in 12 children (25 courses) receiving cisplatin (75-120 mg/m2) either as a continuous 72-h infusion, prolonged single 6-h infusion or repetitive 1-h infusions. Plasma and urinary Pt concentrations were analysed using atomic absorption spectroscopy. Cisplatin-induced nephrotoxicity was determined using creatinine clearance and several glomerular and tubular marker proteins.

RESULTS

Using a two-compartment model the pharmacokinetic parameters for free Pt were: initial half-life 21.6 +/- 9.6 min, terminal half-life 25.9 +/- 16.2 h, area under the plasma concentration-time curve (AUC) 13.5 +/- 4.97 (microg/ml) x h/(100 mg/m2) and cumulative renal elimination(infinity) 41.7 +/- 6.6% of dose. Higher cisplatin delivery rates led to higher peak concentrations of free Pt in plasma and urine and to lower cumulative renal Pt elimination (P < 0.01). During all courses, increases of urinary albumin and alpha1-microglobulin excretion were documented. The creatinine clearance decreased significantly to 70% of baseline values. Correlations were found between both peak free Pt concentrations in plasma and in urine and the maximum of urinary excretions of albumin and of N-acetyl-beta-D-glucosaminidase and the nadir of the glomerular filtration rate (P < 0.05).

CONCLUSIONS

With respect to nephrotoxicity, long-term infusions of cisplatin seem to be preferable over intermittent bolus administration in paediatric patients. The best predictive pharmacokinetic parameters for cisplatin-associated nephrotoxicity in children are peak free Pt concentrations in plasma and urine.

Cisplatin nephrotoxicity in children after continuous 72-h and 3x1-h infusions

Little is known about the association between the rate of cisplatin administration and the severity of cisplatin-induced renal damage in children. The purpose of this study was to compare severity and reversibility of renal damage in children after continuous and repetitive bolus administration of cisplatin and to correlate these data with pharmacokinetic parameters. Study subjects included six children (ten courses) receiving cisplatin as 1-h bolus infusions on three consecutive days (3x40 mg/m2) and four children (eight courses) receiving 72-h continuous infusions (120 mg/m2). In all courses, signs of glomerular and tubular damage were seen, as evidenced by elevated urinary excretion of alpha1-microglobulin, albumin and N-acetyl-beta-D-glucosaminidase and decreased glomerular filtration rate (GFR). Comparing the two infusion regimens, the 1-h bolus administration of cisplatin was followed by significantly higher peak free platinum concentrations in plasma and urine (P<0.001), resulting in lower nadirs of the GFR (P<0.005). Correlations were found between both peak free platinum concentrations in plasma and urine and maxima of urinary albumin and N-acetyl-beta-D-glucosaminidase excretion. Within 12 months after completion of cisplatin therapy, children in the 1-h bolus group had recovered only partially from subclinical nephrotoxicity, with five out of six showing pathological proteinuria. The results provide clear evidence that long-term ciplatin infusions are less nephrotoxic than repetitive bolus infusions.

Efficacy of fludarabine, intermittent sequential high-dose cytosine arabinoside, and mitoxantrone (FIS-HAM) salvage therapy in highly resistant acute leukemias

Patients with refractory acute leukemias after intensive induction and salvage attempts have a particularly poor prognosis and therapeutic options are limited. In the current study, the pharmacologically based FIS-HAM regimen was applied, which included fludarabine 15 mg/m2 q 12 h (days 1, 2, 8, and 9), cytosine arabinoside as a 45-min infusion every 3 h at 750 mg/m2 per single application (days 1, 2, 8, and 9), and mitoxantrone 10 mg/m2 (days 3, 4, 10, 11). Twenty-six intensively pretreated patients [median age: 38 years; range: 22-65; 16 cases of acute myeloid leukemia (AML) and 10 of acute lymphoblastic leukemia (ALL)] were included. Of 16 patients with AML, 5 achieved a complete remission (CR, 31%), 1 a partial remission (PR, 6%), 2 were nonresponders (13%), and 8 succumbed to early death (ED, 50%). Of 10 patients with ALL, 5 achieved a CR, 1 a PR, 1 was a nonresponder, and 3 died early. Overall, the CR rate was 38%. The median disease-free survival time was 50 days and median survival 90 days. Two patients underwent allogeneic bone marrow transplantation and are alive after 27 and 28 months. Neutropenia amounted to a median of 46 days. Toxicity WHO III/IV included infection (61%), diarrhea (48%), nausea/vomiting (43%), impairment of heart function (30%), and mucositis (26%). The current data indicate a significant activity of FIS-HAM chemotherapy in advanced acute leukemias. However, due to its pronounced toxicity, this regimen should be restricted to third-line therapy for patients expecting a suitable donor for allogeneic transplantation, and supportive treatment should be optimized.

Proliferative activity of leukaemic blasts and cytosine arabinoside pharmacodynamics are associated with cytogenetically defined prognostic subgroups in acute myeloid leukaemia

The biological mechanisms responsible for the association of specific karyotypes with prognosis in acute myeloid leukaemia (AML) remain largely unclear. A prospective study was performed to evaluate how far cytogenetically defined prognostic subgroups of AML differ in their proliferative activity as a potential mechanism for differential sensitivities to S-phase-specific induction chemotherapy comprising cytosine arabinoside (AraC). One hundred and eighty-seven patients with de novo AML were included in the study; 25 patients with a favourable [inv(16), t(8;21), t(15;17)] karyotype, 99 with a normal karyotype, 29 with an unfavourable karyotype (-5, 5q-, -7, 7q-, complex aberrations) and 34 with cytogenetic aberrations of unknown prognostic significance (all others). The favourable group demonstrated the highest ex vivo proliferative activity (PA) (3.41 pmol/105 cells), significantly (P = 0.02) exceeding the unfavourable group with the lowest PA (0.72) and the group with a normal karyotype (1.06) or with karyotype of unknown significance (1.05) that both demonstrated an intermediate PA. Samples with a high PA (> median of the whole group) were more likely to produce interleukin 3, granulocyte macrophage colony-stimulating factor (GM-CSF), granulocyte CSF (G-CSF) (56%, 43% and 50%) than cells with a low PA (33%, 36% and 36%; n.s.). The effect of priming by exogenous GM-CSF or G-CSF was significantly more pronounced in samples with a low PA than in rapidly proliferating samples (P < 0.01). For the whole group, a high PA was closely associated with an increased incorporation of AraC triphosphate (AraCTP) into the DNA (P < 0.0001). Clinically, a high PA was associated with a better complete remission (CR) rate in the normal (95% versus 62%) and the unfavourable group (75% versus 33%). The significant differences in proliferative activity between cytogenetic subgroups of AML are associated with increased cytosine arabinoside pharmacodynamics and constitute one potential mechanism for the different response of cytogenetic subgroups to AraC-based induction therapy.

Phase I and pharmacokinetic study of hepatic arterial infusion with oxaliplatin in combination with folinic acid and 5-fluorouracil in patients with hepatic metastases from colorectal cancer

BACKGROUND

To determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD), and pharmacokinetics (PK) of oxaliplatin administered as hepatic arterial infusion.

PATIENTS AND METHODS

Patients with isolated hepatic metastases from colorectal cancer were treated every three weeks with increasing doses of oxaliplatin (4 hours; starting dose 25 mg/m2, escalation in steps of 25 mg/m2) in combination with folinic acid (1 hour, 200 mg/m2) and 5-fluorouracil (2 hour, 600 mg/m2).

RESULTS

Twenty-one patients (median age, 61 years) have been entered all of whom are fully evaluable. The DLT has been observed at dose level 6, i.e., at 150 mg/m2/cycle and consisted of leucopenia, obliteration of the hepatic artery, and acute pancreatitis. Overall, toxicity mainly consisted of nausea/vomiting (16 of 21 patients), anemia (16 of 21), upper abdominal pain (15 of 21), sensory neuropathy (10 of 21), diarrhea (9 of 21), and thrombocytopenia (9 of 21). The mean PK parameters were: terminal half-life of ultrafiltrable platin, 17.75 +/- 9.29 hours; renal elimination, 48.7% +/- 14.1% of the applied dose; renal clearance 135.55 +/- 45.32 ml/min. The mean area under the plasma-concentration curve (AUC) increased linearly from 3.22 +/- 0.61 microg x h/ml to 18.45 +/- 8.90 microg x h/ml through the first five dose levels (P = 0.0004). Ten of eighteen evaluable patients achieved a complete or partial response (59%).

CONCLUSIONS

The recommended dose for phase II studies is 125 mg/m2 oxaliplatin.

Hyperinsulinemia causes activation of the hypothalamus-pituitary-adrenal axis in humans

OBJECTIVE

Hyperactivity of the hypothalamus-pituitary-adrenal (HPA) axis is frequently found in hyperinsulinemic subjects, such as patients with diabetes or abdominal obesity. Here, the question has been posed as to whether hyperinsulinemia increases HPA secretory activity.

METHODS

We performed paired-euglycemic and stepwise hypoglycemic (76-66-56-46 mg/dl)-clamp experiments in two groups (each of 15 healthy men) at different insulin infusions rates, ie, 1.5 mU/min/kg (low-insulin condition) and 15.0 mU/min/kg (high-insulin condition).

RESULTS

During the euglycemic clamp, the high rate insulin infusion increased plasma ACTH levels, whereas plasma ACTH levels remained essentially unchanged during the low-insulin condition (condition by time interaction, P=0.008). Likewise, serum cortisol levels were higher during the high- vs low-insulin condition (condition by time interaction, P=0.004). During the hypoglycemic clamp, plasma ACTH levels did not differ between the low- vs high-insulin condition, while serum cortisol levels were higher during the high- vs low-insulin condition at the beginning of the clamp (plasma glucose approximately 76 mg/dl; P=0.032).

CONCLUSION

Data indicate that hyperinsulinemia acutely increases HPA secretory activity in healthy men. This finding appears to be relevant to the pathogenesis of many clinical abnormalities associated which diabetes and abdominal adiposity, often referred to as the metabolic syndrome.

Gain of an isochromosome 5p: a new recurrent chromosome abnormality in acute monoblastic leukemia

In acute myeloid leukemia (AML) close associations are known between cytomorphology and cytogenetics such as in AML M3/M3v showing a t(15;17) and in AML M4eo associated with inv(16)/t(16;16). In AML M5 a heterogenous cytogenetic pattern is observed. We describe the gain of an isochromosome of the short arm of chromosome 5 together with the gain of chromosome 8 as the sole abnormalities in two cases of acute monoblastic leukemia. In a third case of acute monoblastic leukemia we also observed the gain of an isochromosome 5p together with trisomy 8. This patient showed in addition an unbalanced translocation between the long arm of chromosome 1 and the short arm of chromosome 14 leading to a trisomy 1q. So far only two cases of AML with i(5)(p10) have been published. In no other hematological malignancy has an isochromosome 5p been reported up to now. As an isochromosome 5p can be misinterpreted as a deletion 5q, which occurs frequently in AML, fluorescence in situ hybridization with loci specific probes is a helpful method to detect this rare abnormality.

Detection and separation of the S-adenosylmethionine-decarboxylase inhibitor SAM486A in human plasma and urine by reversed-phase ion-pairing high-performance liquid chromatography

A reversed-phase ion-pairing high-performance liquid chromatography method for the detection and separation of SAM486A in human plasma and urine is described. Precipitation of proteins was used for plasma sample preparation. Enrichment of SAM486A on a 5 micro C18 column using 0.05 M NaH(2)PO(4) and 0.005 M pentan-sulfonic acid (pH 3.0) as eluent was followed by isocratic elution onto a 5 micro C18 analytical column using 0.01 M NaH(2)PO(4) and 0.005 M pentan-sulfonic acid (pH 3.0) as eluent. Analysis time was 23.0 +/- 0.1 min. The separation parameters were: capacacity factor = 6.21; plates/m = 15,002; peak tailing = 2.076. The method is linear between 5 ng/ml (detection limit) and 1000 ng/ml.

Aldehydic lipid peroxidation products derived from linoleic acid

Lipid peroxidation (LPO) processes observed in diseases connected with inflammation involve mainly linoleic acid. Its primary LPO products, 9-hydroperoxy-10,12-octadecadienoic acid (9-HPODE) and 13-hydroperoxy-9,11-octadecadienoic acid (13-HPODE), decompose in multistep degradation reactions. These reactions were investigated in model studies: decomposition of either 9-HPODE or 13-HPODE by Fe(2+) catalyzed air oxidation generates (with the exception of corresponding hydroxy and oxo derivatives) identical products in often nearly equal amounts, pointing to a common intermediate. Pairs of carbonyl compounds were recognized by reacting the oxidation mixtures with pentafluorobenzylhydroxylamine. Even if a pure lipid hydroperoxide is subjected to decomposition a great variety of products is generated, since primary products suffer further transformations. Therefore pure primarily decomposition products of HPODEs were exposed to stirring in air with or without addition of iron ions. Thus we observed that primary products containing the structural element R-CH=CH-CH=CH-CH=O add water and then they are cleaved by retroaldol reactions. 2,4-Decadienal is degraded in the absence of iron ions to 2-butenal, hexanal and 5-oxodecanal. Small amounts of buten-1,4-dial were also detected. Addition of m-chloroperbenzoic acid transforms 2,4-decadienal to 4-hydroxy-2-nonenal. 4,5-Epoxy-2-decenal, synthetically available by treatment of 2,4-decadienal with dimethyldioxirane, is hydrolyzed to 4,5-dihydroxy-2-decenal.

Observation of exotic meson production in the reaction pi- p --> eta'pi- p at 18 GeV/c

An amplitude analysis of an exclusive sample of 5765 events from the reaction pi- p-->eta'pi- p at 18 GeV/c is described. The eta'pi- production is dominated by natural parity exchange and by three partial waves: those with J(PC) = 1(-+), 2(++), and 4(++). A mass-dependent analysis of the partial-wave amplitudes indicates the production of the a2(1320) meson as well as the a4(2040) meson, observed for the first time decaying to eta'pi-. The dominant, exotic (non- qq) 1(-+) partial wave is shown to be resonant with a mass of 1.597+/-0.010(+0.045)(-0.010) GeV/c2 and a width of 0.340+/-0.040+/-0.050 GeV/c2. This exotic state, the pi1(1600), is produced with a t dependence which is different from that of the a2(1320) meson, indicating differences between the production mechanisms for the two states.

Increase in systolic blood pressure and catecholamine level during hyperinsulinemia in a placebo-controlled euglycemic clamp in healthy subjects

Hyperinsulinemia has been shown to induce vasodilation and activation of the sympathetic nervous system. Whether these effects result in changes in blood pressure (BP) is discussed controversially. We measured BP and catecholamine levels in 50 healthy subjects during a 40-min baseline phase and during a 100-min euglycemic clamp phase. In a double-blind, between-subject comparison, 30 subjects were infused with 1.5mU insulin/kg x min, 20subjects were infused with saline solution. Insulin levels increased during insulin infusion from (mean+/-SE) 23.7 0.6 pmol/l to 406.2+/-3.0 pmol/l, but remained unchanged during placebo infusion. Blood glucose levels were identical during both conditions. Systolic BP increased from 116.6+/-1.5 mmHg to 119.8+/-1.8 mmHg during insulin infusion and decreased from 116.6+/-2.3 mmHg to 114.0+/-2.4 mmHg during placebo infusion (p<0.001, for the difference between the effects of insulin vs. placebo). Heart rate was higher during insulin infusion as compared to placebo infusion (63.8+/-1.9 vs. 60.9+/-2.4 beats/min, p<0.05). Norepinephrine levels increased from 1.25+/-0.09 to 1.58+/-0.12 nmol/l during insulin infusion and remained unchanged during placebo infusion (1.24+/-0.09 vs. 1.29+/-0.11 pmol/l; p<0.001). Epinephrine levels were also higher during insulin as compared to placebo infusion (249.8+/-17.4 vs. 212.8+/-21.1 pmol/l, p<0.001). The changes did not depend on whether the subject experienced his first or second clamp. Data demonstrate reproducable increasing effects of hyperinsulinemia within the normal physiological range on catecholamine release and systolic BP in healthy humans.

Rhythms of pituitary-adrenal activity during sleep in patients with Cushing's disease

Previous studies have indicated a dependence of nocturnal pituitary-adrenal secretory activity on central nervous sleep processes in healthy humans: Under normal physiological conditions the release of ACTH/cortisol is inhibited during early sleep and becomes entrained to periods of NonREM sleep during late sleep. Here, we compared nocturnal dynamics in plasma concentrations of ACTH/cortisol in 7 patients with Cushing's disease with those of 7 healthy controls matched in age and sex with the patients. The patients in part were repeatedly tested. The total of 13 nights is composed of 7 nights of hyperpulsatile secretion pattern (5 patients) and 6 nights from hypopulsatile secretion pattern (4 patients). After an adaptation night polysomnographic sleep recordings were obtained and blood was sampled every 15 min between 23.00 and 7.00 h. Controls displayed the typical minimum in ACTH/cortisol concentrations during the early part of the night and maximum concentrations during the late part of the night, whereas ACTH/cortisol levels of Cushing patients indicated a relatively constant elevated pituitary-adrenal activity throughout the night, lacking any circadian variation. Autocorrelation functions revealed the presence of cortisol secretory rhythms with a similar period length in healthy controls (155.6+/-17.4 min) and patients with a hyperpulsatile pattern (142.4+/-6.6 min). In patients displaying hypopulsatility, no significant rhythmicity was observed. However, regardless of the type of secretory pulsatility, adrenal secretory activity started predominantly during periods of NonREM sleep (p<0.01) in healthy controls as well as in patients with Cushing's disease. This data indicates that the normal nocturnal circadian oscillation of pituitary-adrenal activity is absent in Cushing patients, whereas a link between pituitary-adrenal activity and ultradian rhythms of sleep appears to be preserved.

The melanocortin melanocyte-stimulating hormone/adrenocorticotropin(4-10) decreases body fat in humans

The control of body fat is a prominent factor in human health. Animal studies have indicated a homeostatic central nervous system regulation of body fat with particular involvement of the melanocortin receptor pathway. This study provides evidence for a similar role for melanocortins in the long-term control of fat stores in humans. Thirty-six normal weight humans were assigned to one of three experimental groups. After a 4-week baseline, one group was treated with MSH/ACTH(4-10) (MSH/ACTH(4-10)) representing the core sequence of all melanocortins. Another group received desacetyl-alphaMSH, a selective agonist of the brain melanocortin-4 receptor, which shares the 4-10 sequence with MSH/ACTH(4-10). The third group received placebo. Treatments were given intranasally twice daily for 6 weeks, at equimolar doses (MSH/ACTH(4-10), 0.5 mg; desacetyl-alphaMSH, 0.84 mg). Body weight, body composition, and plasma hormone concentrations were measured before and after treatment. MSH/ACTH(4-10) reduced body fat, on the average, by 1.68 kg (P < 0.05) and body weight by 0.79 kg (P < 0.001). Concurrently, plasma leptin levels were decreased by 24% (P < 0.02), and insulin levels were decreased by 20% (P< 0.05) after MSH/ACTH(4-10). Changes after desacetyl-alphaMSH remained nonsignificant. The finding of reduced body adiposity after MSH/ACTH(4-10) confirms and extends to the human the findings of animal models indicating an essential role of the hypothalamic melanocortin system in body weight control.

Carboplatin pharmacokinetics in patients receiving carboplatin and paclitaxel/docetaxel for advanced lung cancers: impact of age and renal function on area under the curve

PURPOSE

To further define the most appropriate way of choosing the dose of carboplatin.

PATIENTS AND METHODS

The pharmacokinetics of carboplatin were analyzed in 30 patients with advanced lung cancer receiving a total of 48 cycles of carboplatin plus paclitaxel/ docetaxel combination chemotherapy. Platin concentrations of ultrafiltrated plasma and urine samples were determined by flameless atomic absorption spectrometry. A multiple regression analysis was performed for interactions between pharmacokinetic parameters and pretreatment characteristics.

RESULTS

Using a twocompartment-model, the following parameters were obtained (mean, coefficient of variation): initial half-life, 0.903 h (48%); terminal half-life, 13.6 h (116%); maximum plasma concentration (Cmax), 38.5 microM (86%); AUC, 111.9 microM/h (86%); volume of distribution, 411 l (130%); total clearance (Ct), 579 ml/min (75%); renal clearance (Cr), 453 ml/min (80%); renal elimination, 76% of dose (17%). In the univariate analysis, age was significantly related to Cmax (P = 0.0303), AUC (P = 0.0050), Ct (P = 0.0020), Cr (P = 0.0092). Plasma creatinine (Crp) was related to Cmax (P = 0.0228), and 1/[Crp] was related to Cmax (P = 0.0015) and AUC (P = 0.0054), while body weight was related to Cmax (P = 0.0365). No interaction with the schedule of application of the two drugs was observed. In the multivariate analysis, factors significantly related to AUC were 1/[Crp] (P < 0.01) and age (P < 0.01). Crp (P < 0.05) and 1/[Crp] (P < 0.01) were significantly associated with Cmax.

CONCLUSIONS

These data stress the importance of dosing carboplatin according to renal function and age and warrant further analyses to validate this concept prospectively.

Hepatic arterial infusion with oxaliplatin, folinic acid, and 5-fluorouracil in patients with hepatic metastases from colorectal cancer: role of carcino-embryonic antigen in assessment of response

BACKGROUND

Therapy for patients with hepatic metastases from colorectal cancer (CRC) remains controversial and may be improved by regional oxaliplatin which proved to be effective when administered systemically to patients with advanced CRC.

METHODS

During the current study, which aims to determine the maximum tolerated dose, the dose-limiting toxicity, and the pharmacokinetics of oxaliplatin applied as hepatic intra-arterial infusion combined with folinic acid and 5-fluorouracil in patients with hepatic metastases from CRC, serial levels of carcino-embryonic antigen were determined and their relationship to response to therapy was assessed.

RESULTS

Toxicity mainly consisted of nausea, pain, mucositis, sensorial neuropathy, diarrhoea, and thrombocytopenia. The results of tumor marker analyses suggest that progressive disease may be detected early by increasing CEA levels and responsive disease may be characterized by low or decreasing values.

CONCLUSIONS

Further analyses are warranted to determine the role of CEA in the assessment of response as compared to imaging techniques.

Prophylactic action of oral fluconazole against fungal infection in neutropenic patients. A meta-analysis of 16 randomized, controlled trials

BACKGROUND

Fluconazole is used widely for fungal prophylaxis. Although studies with bone marrow transplantation (BMT) recipients clearly showed the usefulness of oral fluconazole, results of the studies in neutropenic patients other than BMT recipients have been inconsistent. Therefore, the authors performed a meta-analysis to evaluate the efficacy of fluconazole prophylaxis during chemotherapy-induced neutropenia.

METHODS

The authors identified reports that were not restricted to those in English and not restricted to published trials through MEDLINE, CANCERLIT, or the data base of the Pfizer company. The authors included prospective, randomized studies comparing oral fluconazole with placebo, no treatment, or oral polyenes as prophylaxis for fungal infections in neutropenic patients. Two independent authors extracted data from 16 trials with 3734 patients enrolled. The outcome measures were the development of fungal-related death, systemic and superficial fungal infections, the use of empiric intravenous amphotericin-B, and infections or colonization with fluconazole-resistant fungi. The summarized odds ratios (ORs) were calculated using the Mantel-Haenszel method and the DerSimonian-Laird method.

RESULTS

Prophylactic fluconazole was not effective in reducing fungal-related death or in reducing proven, systemic fungal infections in non-BMT patients (OR, 0.91; 95% confidence interval [CI], 0.30-2.82 and OR, 0.85; 95% CI, 0.47-1.55, respectively). However, fluconazole was very effective in reducing superficial fungal infections (OR, 0.44; 95% CI, 0.24-0.80), even when it was given in lower doses (50-200 mg per day). There was no increase in proven, systemic infection of fluconazole-resistant fungi, although colonization of those fungi increased. When the results were combined in studies in which the incidence of systemic fungal infections was > 15%, fluconazole was effective in reducing such infections (OR, 0.23; 95% CI, 0.15-0.36).

CONCLUSIONS

The current analyses failed to find an effect of fluconazole on both fatal fungal infection and systemic fungal infection in non-BMT patients. Further studies on severely neutropenic patients are warranted because prophylactic fluconazole seemed to be effective when the incidence of systemic fungal infection was expected to be > 15%.