[The use of bronchial fibroscopy for difficult intubations in maxillofacial surgery]

BACKGROUND

Evaluation of difficulties and modalities of tracheal intubation in maxillofacial surgery.

METHODS

DESIGN

retrospective study.

SETTING

maxillofacial operation room. 2152 patients who underwent elective maxillofacial surgery during a five-year time, from 1994 to 1998. Indications and alternative modalities of tracheal intubation through fiberoptic bronchoscope in eight patients (0.37%) with preoperatively evaluated difficult intubation due to temporomandibular ankylosis (3 patients), burns sequelae (1 patient), craniofacial congenital malformations (2 patients), unstables fractures of the cervical spine (2 patients), are discussed. Fiberoptic bronchoscope was used through nasotracheal route under topical nasal and laryngeal anaesthesia, combined with appropriate benzoanalgesia, in order to maintain spontaneous breathing. Proper positioning of tracheal tube was directly checked by fiberoptic bronchoscope, through visualization of the tracheal carina.

RESULTS

In seven patients tracheal intubation was easily performed without complications in less than 20 minutes. In the eight patients the time spent was 35 minutes, due to important nasal bleeding, which caused a change of the nostril.

CONCLUSION

Among the alternative methods of elective tracheal intubation, previously evaluated as difficult or impossible using conventional laryngoscopy, the use of fiberoptic bronchoscope seems to be safest and easiest to use, although not the cheapest.

AlphaANP, AVP, and pituitary-thyroid axis in patients with congestive heart failure and acute respiratory failure

The pituitary-thyroid axis and neurohumoral activation indexes were simultaneously investigated in 16 in-patients hospitalized for cardiac heart failure (CHF), New York Heart Association (NYHA), class II-IV, and Killip clinical scale, class II-III, to evaluate their relationship with CHF morbidity and the relative prognostic value. At entry the patients were divided into two subgroups (A and B), according to the severity of CHF. Patients were further classified into two subgroups, according to the subsequent clinical course (C, poor outcome and D, improved clinical course). Blood samples were obtained every day for the radioimmunoassay measurement of plasma alpha-atrial natriuretic peptide (alphaANP), arginine vasopressin (AVP), and thyroid hormones, and the results were compared with those of 12 control subjects. At admission, alphaANP and 3,3',5'-triiodothyronine (rT3) values were higher, while 3,3',5-triiodothyronine (T3) to rT3 (T3/rT3) ratio was lower in subgroups A and B than in controls (p<0.001), respectively, and in C than in D (p<0.001), respectively, according to the prognosis. Conversely, no differences in other thyroid indexes, nor a significant correlation between alphaANP and either rT3 or T3/rT3 ratio were present in any of the subgroups. AVP plasma levels in subgroup A were not statistically different from those of controls, whereas they were significantly decreased in subgroups B and C (p<0.05) and D (p<0.001). In conclusion, these results indicate that in CHF the pituitary-thyroid axis is not altered, that alphaANP and T3/rT3 ratio are non-invasive and reliable predictors of severity and prognosis, while AVP might be affected by the different pathological processes leading to CHF or by the concomitant use of drugs.

Clinical relevance of retroperitoneal involvement from epithelial ovarian tumors of borderline malignancy

Rota SM, Zanetta G, Ieda N, Rossi R, Chiari S, Perego P, Mangioni C. Clinical relevance of retroperitoneal involvement from epithelial ovarian tumors of borderline malignancy. Ovarian tumors of borderline malignancy have an outstanding prognosis. The need for aggressive surgical staging is questionable and the need for retroperitoneal node sampling is debated. From 1982 to 1996, 81 women underwent surgical staging including retroperitoneal sampling. Three patients (3.7%) with serous tumor had microscopic nodal involvement. Retroperitoneal metastases were found in two intraperitoneal stage I tumors and in one stage IIIA tumor. Positive nodes were found in 1/31 (3.2%) women undergoing sampling of para-aortic nodes and in 2/69 (2.8%) women undergoing sampling of pelvic nodes. With a median follow-up of 79 months we observed five recurrences, but none involved the retroperitoneum. The three patients with positive nodes remain alive without disease. Among 236 patients with diagnosis of borderline tumor but without sampling of the nodes, we observed one retroperitoneal recurrence (0.4%) in a serous tumor. There are no indications for retroperitoneal sampling of mucinous borderline tumors. For serous tumors this procedure should only be performed as a part of prospective trials. The clinical relevance of retroperitoneal involvement in borderline tumors appears minimal and does not justify routine aggressive surgery.

Effects of transdermal 17beta-estradiol on left ventricular anatomy and performance in hypertensive women

To reduce cardiovascular complications, antihypertensive therapy should not only normalize blood pressure but also induce a regression of structural abnormalities, which are the expression of end-organ damage. We investigated the effects of transdermal 17beta-estradiol, combined with standard antihypertensive therapy, on the modification of left ventricular anatomy and systolic performance in hypertensive postmenopausal women. In a randomized, double-blind, placebo-controlled study, we enrolled 169 postmenopausal women with mild or moderate hypertension. Eighty-six patients (group 1) received transdermal 17beta-estradiol (50 microg/d) and norethisterone acetate (2.5 mg/d, orally), and 83 patients (group 2) received placebo. At baseline, all women underwent M-mode and 2-D echocardiogram, which was repeated after 6, 12, and 18 months of follow-up. After 18 months of treatment, we observed a significant decrease in left ventricular diastolic septal and posterior wall thickness and mass in both groups. Furthermore, after 18 months, left ventricular mass was significantly less than in the estrogen-treated group. No significant modifications were observed in left ventricular systolic and diastolic dimensions or in systolic performance, as expressed by left ventricular fractional shortening. In conclusion, transdermal 17beta-estradiol, which is associated with antihypertensive therapy, may contribute in the reduction of left ventricular mass in hypertensive postmenopausal women.

Molecular cytogenetic analysis of the karyotype of the European Atlantic sturgeon, Acipenser sturio

A karyotype analysis was carried out on the European Atlantic sturgeon, Acipenser sturio (2n=121 +/- 3). The telomeric sequence repeat (TTAGGG)n detected by fluorescent in situ hybridization (FISH) was mostly localized at the telomeres of all chromosomes. Ribosomal DNA (rDNA) genes were detected by silver staining techniques and by FISH with digoxigenin-labelled probe for 28S rDNA. Silver staining detected active NORs in the telomeric regions of six chromosomes, and by FISH one or two additional minor sites were detected. The 5S rDNA was found in the interstitial region of a small metacentric pair. The 5S rRNA gene was completely sequenced for the first time in a sturgeon species. The A. sturio karyotype organization is discussed in relation to phylogenesis of the species within the Acipenseridae and to polyploidization events characterizing sturgeon evolution.

[Multidisciplinary management of malignant hepatic tumors in children: a recent national experience]

BACKGROUND

Malignant hepatic tumors (Mht) are rare in children. Among them hepatoblastoma (HB) is the most common.

AIM

To report the results of the multidisciplinary management in 6 consecutive children: five HB and one metastatic Wilms tumor (MWT).

PATIENTS AND METHODS

The mean age of patients was 42 months. All HB patients had elevated serum alfafetoprotein (median 150,000 ng/ml). All patients received preoperative chemotherapy: HB patients received carboplatin/doxorubicin alternating with cisplatin, and the MWT patient, vincristine alone. Surgery included two formal right and two formal left hepatectomies, one extensive central resection with partial left segmentectomy, and one lateral segmentectomy. Extracorporeal circulation was used in the child with atrial involvement. All patients received postoperative chemotherapy.

RESULTS

All tumors had variable regresion on preoperative chemotherapy. Complete resection with negative margins was achieved in all patients. The degree of tumor necrosis on histology ranged from 60% to 90%. Alfafetoprotein levels fell to under 10 ng/ml in all HB cases, one to three months after surgery. All patients survive free of disease at a median follow up of 19 months.

CONCLUSION

A multidisciplinary approach including the well timed used of chemotherapy and surgery is highly effective in the management of pediatric malignant tumors.

Local versus central assessment of venographies in a multicenter trial on the prevention of deep vein thrombosis in neurosurgery

Venography is the diagnostic method of choice for end-point measurement in multicenter trials on the prevention of postoperative deep vein thrombosis (DVT). The aim of the study was to determine the inter-observer agreement between the local and central assessment of venographies in a multicenter trial comparing enoxaparin and placebo in the prevention of DVT after elective neurosurgery. The study was run in seven centers experienced in venography trials on DVT prevention. The central and local adjudication panels were both blind with respect to the assigned treatment. The central panel was unaware of the local adjudication. Venographies were adjudicated as positive, negative or inadequate for adjudication and positive venographies as proximal or distal DVT. Inter-observer agreement was assessed according to the Cohen's inter-observer variability index (K index). All 266 venographies (8 monolateral) were considered adequate for adjudication by both the central and local panels. A disagreement was found in 25 cases; K index = 0.75. Fourteen venographies adjudicated as negative centrally were considered positive locally (3 were proximal DVT). Eleven venographies adjudicated as positive centrally (1 was a proximal DVT) were considered negative locally. Enoxaparin was found to be more effective than placebo according to both the central and local adjudication: 16.9% versus 32.6% (Relative risk, RR = 0.52; CI 95% 0.33-0.82) according to central adjudication; 18.5% versus 33.3% (RR = 0.56; CI 95% 0.36-0.87) according to local adjudication. We conclude that a good inter-observer agreement in the assessment of venography was observed between the central and local adjudication in a study on DVT prevention run in a restricted experienced study framework. The cost and work overloading of central assessment of venographies in this study framework seems not to be justified.

The replication factory targeting sequence/PCNA-binding site is required in G(1) to control the phosphorylation status of DNA ligase I

The recruitment of DNA ligase I to replication foci in S phase depends on a replication factory targeting sequence that also mediates the interaction with proliferating cell nuclear antigen (PCNA) in vitro. By exploiting a monoclonal antibody directed at a phospho-epitope, we demonstrate that Ser66 of DNA ligase I, which is part of a strong CKII consensus site, is phosphorylated in a cell cycle-dependent manner. After dephosphorylation in early G(1), the level of Ser66 phosphorylation is minimal in G(1), increases progressively in S and peaks in G(2)/M phase. The analysis of epitope-tagged DNA ligase I mutants demonstrates that dephosphorylation of Ser66 requires both the nuclear localization and the PCNA-binding site of the enzyme. Finally, we show that DNA ligase I and PCNA interact in vivo in G(1) and S phase but not in G(2)/M. We propose that dephosphorylation of Ser66 is part of a novel control mechanism to establish the pre-replicative form of DNA ligase I.

Chronic neuroborreliosis in infancy

Lyme disease is a polymorphic and multisystemic disease caused by Borrelia burgdorferi. Neurological manifestations are found in 10%-50% of cases. We present 2 cases followed for 5 and 6 years of chronic relapsing-remitting neuroborreliosis. Diagnosis of neuroborreliosis in these cases was based on serum and cerebrospinal fluid findings. We discuss clinical, neurophysiological, laboratory and instrumental aspects regarding the difficulties of reaching a correct diagnosis. Further studies, especially in the field of immunology, should help identify the mechanisms responsible for the disease becoming chronic. With this knowledge, it may be possible to design immunological therapies for relapses, and to prevent the evolution of the disease.

Fluorescent in situ hybridization with rDNA probes on chromosomes of Acipenser ruthenus and Acipenser naccarii (Osteichthyes Acipenseriformes)

The genes for 28S and 5S rDNA were physically mapped on the chromosomes of two sturgeon species, the sterlet (Acipenser ruthenus, 2n = 118 ± 4) and the Adriatic sturgeon (Acipenser naccarii, 2n = 248 ± 4) by fluorescent in situ hybridization. In the sterlet, the 28S rDNA was located on six chromosomes, four of which actively transcribed, while in the Adriatic sturgeon the 28S rDNA was located on a chromosome number ranging from 10 to 12, eight of which actively transcribed. The 5S rDNA was physically mapped on two chromosomes in the sterlet and on four in the Adriatic sturgeon. A more detailed characterization of the latter karyotype was obtained during this study. All these data are discussed in connection with the ploidy relationships among sturgeon species.Key words: karyotype, ploidy, FISH, 28S and 5S rDNA.

Nimodipine in subcortical vascular dementia trial

Vascular dementia (VaD) is a heterogeneous pathology currently regarded as the result of a variety of causes. Different types of VaD can be identified according to different criteria. This heterogeneity might be one of the causes of the controversial results observed, up to now, in clinical trials. Recently, the 10th revision of the International Classification of Diseases (ICD-10) explicitly identified subcortical VaD as a well-defined subgroup. Abnormalities of white matter are clearly detectable with computed tomography or magnetic resonance scans. The clinicoradiological association of dementia, blood hypertension, and other vascular risk factors, extensive white matter lesions, and small subcortical infarcts might be considered as a clinical univocal entity. Following the encouraging results of a preliminary pilot study, the above-mentioned criteria were followed to define a population of patients to be enrolled in a double-blind, parallel-groups, placebo-controlled clinical trial with nimodipine, which has been proposed as a drug that can improve cognitive functions in patients with VaD. The paper discusses the protocol design of this ongoing trial and its main entry criteria, with particular emphasis on the definition of the population to be enrolled. Implication for future trials in subcortical VaD are discussed further.

Neonatal screening for hearing disorders in infants at risk: incidence, risk factors, and follow-up

OBJECTIVE

To determine the incidence and risk factors for hearing disorders in a selected group of neonates and the feasibility of selective hearing screening.

SETTINGS

Multicenter prospective trial at five centers in Germany.

METHODS

Enrollment criteria: in addition to previously defined risk factors by the Joint Committee on Infant Hearing (family history of hearing loss, in utero infections, craniofacial anomalies, birth weight <1500 g, critical hyperbilirubinemia, ototoxic medications, bacterial meningitis, postnatal asphyxia, mechanical ventilation >5 days, stigmata, or syndromes associated with hearing loss), the impact of maternal drug abuse, birth weight <10th percentile, persistent pulmonary hypertension, and intracranial hemorrhage more than or equal to grade III or periventricular leukomalacia on infant hearing were evaluated. The screening procedure was performed by automated auditory brainstem response (A-ABR; ALGO 1-plus; Natus Med Inc, San Carlos, CA).

STATISTICS

univariate analyses of risk factors versus A-ABR results and a multivariate regression analysis were used; additionally, the total test time was recorded.

RESULTS

Seven hundred seventy recordings from 777 infants enrolled consecutively constitute the basis of this analysis. Mean gestational age was 33.8 +/- 4.3 weeks, birth weight 2141 +/- 968 g; 431 infants being male and 339 female; 41 (5.3%) infants exhibited pathologic A-ABR results (16 bilateral and 25 unilateral). Meningitis or sepsis, craniofacial malformations, and familial hearing loss were independent significant risk factors. Median total test time was 25 minutes. Follow-up examinations in 31 infants revealed persistent hearing loss in 18 infants (13 infants sensorineural, 5 from mixed disorders), 7 requiring amplification.

CONCLUSION

Hearing screening in high-risk neonates revealed a total of 5% of infants with pathologic A-ABR (bilateral 2%). Significant risk factors were familial hearing loss, bacterial infections, and craniofacial abnormalities. Other perinatal complications did not significantly influence screening results indicating improved perinatal handling in a neonatal population at risk for hearing disorders.

Double-blind randomized placebo-controlled study of transdermal estrogen replacement therapy on hypertensive postmenopausal women

We investigated the effects of transdermal 17beta-estradiol, combined with standard antihypertensive therapy, on the modification of the cardiovascular risk profile in hypertensive postmenopausal women. In a randomized, double-blind, placebo-controlled study, we enrolled 200 postmenopausal women with mild to moderate hypertension. Patients received 17beta-estradiol (50 microg/day, transdermal) and norethisterone acetate (2.5 mg/ day, orally) or placebo. At baseline serum total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, glucose, and fibrinogen plasma levels were measured and all subjects underwent complete M-mode and 2-D echocardiograms, which were repeated after 6, 12, and 18 months of hormonal replacement therapy. Compared with placebo, all values decreased significantly except for HDL cholesterol. In both groups, no modifications were observed in echocardiographic parameters, except for left ventricular mean diastolic and systolic wall thickness and left ventricular mass index, which showed a significant decrease in both groups. The reduction was greater in the treated group; the percentage of patients with left ventricular hypertrophy was 46% before randomization and 17.2% after 18 months of treatment (P < .0001), whereas in group II the percentage was 48% at baseline and 31.5% after 18 months (P < .05). In conclusion, transdermal 17beta-estradiol, associated with antihypertensive therapy, may contribute to the reduction of cardiovascular risk profile in hypertensive postmenopausal women.

Use of a Caco-2 cell culture model for the characterization of intestinal absorption of antibiotics

The use of cell culture models, based on human cell lines derived from the intestinal epithelium, is a promising new tool for the in vitro study of oral absorption of drugs. An assay has been developed using the Caco-2 cell line with the aim of studying the in vitro permeability of antibiotics. The reproducibility of the assay conditions have been assessed by means of the transport of two different marker molecules: 3H-mannitol and fluorescein, and transepithelial electrical resistance (TEER) value for cells monolayers. The results show that cells after 21 days of culture give significantly tighter monolayers than those after 15 days with higher reproducibility. Apparent permeability coefficients (Papp) have been measured for 13 antibiotics, known to be absorbed at different rates in humans. Papp values span from 0.18 x 10(-6) cm/s for cephaloridine to 5.79 x 10(-6) cm/s for rifampicin where the corresponding bioavailability values, known from literature, span from < 3 to 98%. A Caco-2 in vitro model appears to be suitable to investigate the transport of drugs across the intestinal epithelium. This model gives no information about the metabolic phase that follows the absorption of a drug but could provide information to investigate its pharmacokinetical behavior.

Introduction of heteroplasmic mitochondrial DNA (mtDNA) from a patient with NARP into two human rho degrees cell lines is associated either with selection and maintenance of NARP mutant mtDNA or failure to maintain mtDNA

Mitochondria from a patient heteroplasmic at nucleo-tide position 8993 of mitochondrial DNA (mtDNA) were introduced into two human tumour cell lines lacking mtDNA. The donor mitochondria contained between 85 and 95% 8993G:C mtDNA. All detectable mtDNA in the mitochondrially transformed cells contained the pathological 8993G:C mutation 3 months after transformation. These results suggest that 8993G:C mtDNA had a selective advantage over 8993T:A mtDNA in both lung carcinoma and osteo-sarcoma cell backgrounds. In contrast, two other presumed pathological mtDNA variants were lost in favour of 'wild-type' mtDNA molecules in the same lung carcinoma cell background. Taken together, these findings suggest that the transmission bias of mtDNA variants is dependent upon a combination of nuclear background and mtDNA genotype. A second phenomenon observed was a marked decrease in the growth rate of many putative transformed cell lines after 6 weeks of culturing in selective medium, and in these cell lines mtDNA was not readily detectable by Southern blotting. Restriction endonuclease analysis and sequencing of amplified mtDNA demonstrated that the slow growing cells contained little or no mtDNA. It is concluded that these cells represented transient mitochondrial transformants.

Ozonation of blood during extracorporeal circulation. I. Rationale, methodology and preliminary studies

We investigated whether exposure of blood ex-vivo to oxygen-ozone (O2-O3) through a gas exchanger is feasible and practical. We first evaluated the classical dialysis-type technique but we soon realized that semipermeable membranes are unsuitable because they are hydrophilic and vulnerable to O3. We therefore adopted a system with hydrophobic O3-resistant hollow fibers enclosed in a polycarbonate housing with a membrane area of about 0.5 m2. First we tested the system with normal saline, determining the production of hydrogen peroxide (H2O2) at O3 concentrations from 5 to 40 microg/ml. We then evaluated critical parameters by circulating swine blood in vitro; this revealed that heparin is not an ideal anticoagulant for this system. Finally, we performed several experiments in sheep and defined optimal anticoagulant dose (sodium citrate, ACD), priming solution, volume of blood flow per min, volume and concentration of O2-O3 mixture flowing countercurrent with respect to blood and the time necessary for perfusion in vivo. The biochemical parameters showed that an O3 concentration as low as 10 microg/ml is effective; this means that gas exchange and O3 reactivity are rapid and capable of inducing biological effects. The sheep showed no adverse effects even after 50 min of extracorporeal circulation at higher O3 concentrations (20 to 40 microg/ml) but the exchanger became less effective (low pO2 values) due to progressive clogging with cells.

Fluoro-Gold: An alternative viability stain for multicolor flow cytometric analysis

BACKGROUND

The viability stains propidium iodide (PI) and 7-amino-actinomycin D (7-AAD) are excited at 488 nm, as are the commonly used antibody conjugates fluorescein isothiocyanate (FITC), phycoerythrin (PE), and cyanine 5 dye covalently coupled to R-phycoerythrin (RPE-Cy5). When excited by a single laser, spectral overlap in the emission of PI and 7-AAD with RPE-Cy5 precludes the use of these viability stains for three-color immunophenotyping, particularly when evaluating low levels of marker expression in viable target cells. The ultraviolet excitable dye hydroxystilbamidine methanesulfonate (Fluoro-Gold, or FG) binds to DNA at the A-T-rich regions of the minor groove in permeabilized or dead cells. We assessed the suitability of this dye as a viability stain.

METHODS

The ability of FG to detect nonviable cells in fresh and cryopreserved human apheresed peripheral blood cells was compared with that of PI and 7-AAD. The stability of FG staining and the effects of dye and cell concentration on the discrimination of nonviable cells was determined by measuring changes in the median fluorescence of viable and nonviable cells.

RESULTS

FG labeling at dye concentrations of 2-8 microM is stable for at least 3 h over a wide range of cell concentrations (4 x 10(5) to 4 x 10(7) cells/ml). Costaining studies and linear regression analysis show that cell viability as determined by FG is strongly correlated with estimates using PI (r = 0.9636) and 7-AAD (r = 0.9879).

CONCLUSIONS

FG is a reliable, alternative viability stain that can be used in conjunction with fluorochromes including FITC, PE, and RPE-Cy5 for multicolor analysis using dual-laser instruments.

Validity of different linguistic versions of the Alzheimer's Disease Assessment Scale in an international multicentre Alzheimer's disease trial

Owing to the involvement of Italian Centres in a multicentre, German-Italian therapeutical trial with Alzheimer's dementia patients, to be assessed with the Alzheimer's Disease Assessment Scale (ADAS), it was decided that the Italian centres would use an Italian version of the scale, derived from that used by the German centres. However, the lists of words for exploring verbal memory are not merely translated from the German version, but are composed of selective Italian words chosen according to linguistic criteria. This Italian version was validated following the same procedure adopted for validating the German version. We submitted this Italian version to an interrater reliability, test-retest reliability, concurrent validity, internal consistency and sensitivity evaluation, using demented patients. Based on the results of these tests this Italian version of the ADAS proved valid and reliable. Moreover, the results were strikingly comparable to those from the validation of the German version. Our work supports the validity, reliability and transnational comparability of national versions of the ADAS constructed following definite linguistic criteria.

Speeds of actin translocation in vitro by myosins extracted from single rat muscle fibres of different types

As skeletal muscle fibres mostly express a single myosin isoform, they are a potential source of pure myosin isoforms. A technique is described that allows extraction and identification of pure myosin isoforms from single fibres, and testing of such myosins in an in vitro motility assay (IVMA). The results show that the extraction procedure does not alter myosin function and support the view that single fibres are reliable sources of purified myosin isoforms for IVMA.

Altered multidrug resistance phenotype caused by anthracycline analogues and cytosine arabinoside in myeloid leukemia

The expression of P-glycoprotein (Pgp) is often increased in acute myeloid leukemia (AML). However, little is known of the regulation of Pgp expression by cytotoxics in AML. We examined whether Pgp expression and function in leukemic blasts was altered after a short exposure to cytotoxics. Blasts were isolated from 19 patients with AML (15 patients) or chronic myeloid leukemia in blastic transformation (BT-CML, 4 patients). Pgp expression and function were analyzed by flow cytometric analysis of MRK 16 binding and Rhodamine 123 retention, respectively. At equitoxic concentrations, ex vivo exposure for 16 hours to the anthracyclines epirubicin (EPI), daunomycin (DAU), idarubicin (IDA), or MX2 or the nucleoside analogue cytosine arabinoside (AraC) differentially upregulated MDR1/Pgp expression in Pgp-negative and Pgp-positive blast cells. In Pgp-negative blasts, all four anthracyclines and AraC significantly increased Pgp expression (P =.01) and Pgp function (P =.03). In contrast, MX2, DAU, and AraC were the most potent in inducing Pgp expression and function in Pgp positive blasts (P <.05). A good correlation between increased Pgp expression and function was observed in Pgp-negative (r =.90, P =.0001) and Pgp-positive blasts (r =.77, P =.0002). This increase in Pgp expression and function was inhibited by the addition of 1 micromol/L PSC 833 to blast cells at the time of their exposure to these cytotoxics. In 1 patient with AML, an increase in Pgp levels was observed in vivo at 4 and 16 hours after the administration of standard chemotherapy with DAU/AraC. Upregulation of Pgp expression was also demonstrated ex vivo in blasts harvested from this patient before the commencement of treatment. In 3 other cases (1 patient with AML and 2 with BT-CML) in which blasts were Pgp negative at the time of initial clinical presentation, serial samples at 1 to 5 months after chemotherapy showed the presence of Pgp-positive blasts. All 3 patients had refractory disease. Interestingly, in all 3 cases, upregulation of Pgp by cytotoxics was demonstrated ex vivo in blasts harvested at the time of presentation. These data suggest that upregulation of the MDR1 gene may represent a normal response of leukemic cells to cytotoxic stress and may contribute to clinical drug resistance.

Prognosis of pediatric bone marrow transplant recipients requiring mechanical ventilation

OBJECTIVES

To assess the prognosis of pediatric bone marrow transplant recipients requiring mechanical ventilation and to identify risk factors for mortality.

DESIGN

Retrospective chart review.

SETTING

Pediatric intensive care unit (PICU), tertiary care center.

PATIENTS

Inclusion criteria were endotracheal intubation and mechanical ventilation after bone marrow transplantation; patients with perioperative ventilation were excluded. Outcome measures were extubation, PICU discharge, and 6-month survival. The 39 patients who met the inclusion criteria were ventilated on 41 occasions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Overall survival rate to PICU discharge was 44% (17 of 39 patients). Six months after PICU discharge, 14 of these children were still alive, for a medium-term survival rate of 36%. Preexisting conditions (primary disease, bone marrow engraftment, or graft-vs.-host disease) had no significant effect on survival. Multiple organ failure, especially pulmonary failure and neurologic deterioration, were significant determinants of patient survival.

CONCLUSIONS

The observed prognosis is improved over previous reports. Early initiation of aggressive intensive care treatment is warranted in this patient group. Decisions regarding intensity of treatment must be based on aspects of the acute illness rather than on the primary conditions.

Effect of the H1-histamine receptor agonist betahistine on drinking and eating behavior in pygmy goats

The effect of different doses of the H1-receptor agonist betahistine (0.9 and 2, 4 and 8 mg/kg b.wt.(0.75)) on water and food intake was investigated in 12 pygmy goats. Intraperitoneal (i.p.) injection of betahistine (2, 4, and 8 mg/kg b.wt.(0.75)) stimulated drinking in a dose-dependent manner. Food intake was decreased after the injection of 4 or 8 mg/kg b.wt.(0.75) betahistine, respectively. The increase in water intake was characterized by an increased draft size and decreased latency to drink. The decrease in food intake at the highest dose tested was characterized by an increased latency to eat and by a decreased meal frequency, and food intake associated to drinking was decreased. In line with previous studies, these results support the hypothesis that food-associated drinking is mediated by stimulation of H1-receptors of histamine in pygmy goats.