Interleukin-3 promotes proliferation and differentiation of human hematopoietic stem cells but reduces their repopulation potential in NOD/SCID mice

In the present study we explored systematically the influence of human interleukin-3 (IL-3) on the cord blood (CB) cell-derived production of human hematopoietic cells in the bone marrow, blood, and spleen of chimeric nonobese/severe combined immunodeficient mice ((NOD/SCID) mice. CB mononuclear cells and MACS-enriched CB CD34(+) cells were injected into irradiated NOD/SCID mice. The mice were additionally transplanted with a stably transfected rat fibroblast cell line expressing the human IL-3 gene (Rat-IL-3) constitutively, or with the nontransfected rat fibroblast cell line as a control (Rat-1). Rat-IL-3 mice displayed a higher engraftment of human hematopoietic cells in bone marrow, spleen, and peripheral blood compared with mice with Rat-1 cotransplantation. When we transplanted their total bone marrow cell population into secondary mice, surprisingly, mice transplanted with bone marrow cells from Rat-1 mice displayed a higher proportion of human hematopoietic cells compared with Rat-IL-3 mice. As expected, bone marrow cultures (BMCs) from Rat-IL-3 mice contained a higher proportion of human cells than Rat-1 bone marrow cells. However, when BMCs were passaged to new flasks, we observed a higher proportion of human cells in BMCs from Rat-1 mice compared with BMCs from Rat-IL-3 mice. IL-3 promotes the proliferation and differentiation of hematopoietic stem cells in chimeric bone marrow. In addition, IL-3 may play a role in the depletion of hematopoietic stem cells in chimeric bone marrow. In the absence of IL-3, the hematopoietic stem cells may remain in a quiescent state and proliferation can be induced by stimuli, including secondary transplantation or cell passage.     

Ran's C-terminal,basic patch,and nucleotide exchange mechanisms in light of a canonical structure for Rab,Rho, Ras,and Ran GTPases

Proteins comprising the core of the eukaryotic cellular machinery are often highly conserved, presumably due to selective constraints maintaining important structural features. We have developed statistical procedures to decompose these constraints into distinct categories and to pinpoint critical structural features within each category. When applied to P-loop GTPases, this revealed within Rab, Rho, Ras, and Ran a canonical network of molecular interactions centered on bound nucleotide. This network presumably performs a crucial structural and/or mechanistic role considering that it has persisted for more than a billion years after the divergence of these families. We call these 'FY-pivot' GTPases after their most distinguishing feature, a phenylalanine or tyrosine that functions as a pivot within this network. Specific families deviate somewhat from canonical features in interesting ways, presumably reflecting their functional specialization during evolution. We illustrate this here for Ran GTPases, within which two highly conserved histidines, His30 and His139, strikingly diverge from their canonical counterparts. These, along with other residues specifically conserved in Ran, such as Tyr98, Lys99, and Phe138, appear to work in conjunction with FY-pivot canonical residues to facilitate alternative conformations in which these histidines are strategically positioned to couple Ran's basic patch and C-terminal switch to nucleotide exchange and effector binding. Other core components of the cellular machinery are likewise amenable to this approach, which we term Contrast Hierarchical Alignment and Interaction Network (CHAIN) analysis.     

Pericardial Disease in Pregnancy

Background: There is no evidence that pregnancy affects susceptibility to pericardial disease. However, when such a condition occurs, its proper diagnosis and management may be crucial for the outcome of the pregnancy. Incidence and Diagnosis: Hydropericardium is the most frequent form of pericardial involvement in pregnancy. It is typically a small, clinically silent pericardial effusion present in the third trimester in approximately 40% of healthy pregnant women. Small amounts of fetal pericardial fluid (< 2 mm in echocardiography, in diastole) can be detected after 20 weeks of gestation. Larger effusions should raise clinical concern for hydrops fetalis, Rh disease, hypoalbuminemia, and infectious or autoimmune disorder. Wide varieties of etiologic forms of pericardial diseases occur sporadically in pregnant women. Significant symptoms, electrocardiographic changes, or physiologic impairment warrant hospitalization. Treatment: Most pericardial disorders are managed during pregnancy as in nonpregnant patients (i.e., nonsteroidal antiinflammatory drugs for acute, antibiotics and drainage for purulent pericarditis, and corticosteroids for systemic autoimmune disorders). However, colchicine is contraindicated in pregnancy, and pericardiocentesis should be performed only for very large effusions causing clinical signs of cardiac tamponade or if presence of suppurative, tuberculous or neoplastic pericardial effusion is suspected. Echocardiographic guidance of pericardiocentesis is preferred to fluoroscopic guidance in order to avoid fetal X-ray exposure. Pericardiectomy should be reserved for significant pericardial constriction and resistant bacterial infections. Delivery of normal infants in term after pericardiocentesis or pericardiectomy is expected, whenever natural history of causative disease allows. Pericardiectomy itself is not a contraindication for subsequent successful pregnancies. Zusammenfassung. Hintergrund: Hinweise dafür, dass eine Schwangerschaft zur Entstehung von Perikarderkrankungen prädisponiert oder deren Ausbildung beeinflusst, gibt es nicht. Wenn aber während der Schwangerschaft eine Perikarderkrankung auftritt, sind eine schnelle Diagnose und die richtige Behandlung von großer Bedeutung. Inzidenz und Diagnose: Die häufigste Form eines Perikardergusses während der Schwangerschaft ist das "Hydroperikard". Es handelt sich typischerweise um das Auftreten eines kleinen, klinisch nicht relevanten Perikardergusses im dritten Trimenon der Schwangerschaft. Bei ca. 40% aller gesunden Schwangeren ist ein solcher minimaler Erguss nachweisbar. In der 20. Schwangerschaftswoche kann auch bei den Feten ein kleiner Perikarderguss nachgewiesen werden, der in der fetalen Echokardiographie eine Separation von < 2 mm zeigen sollte. Größere Ergüsse sind meist das erste klinische Zeichen für einen Hydrops fetalis, eine Rhesus-Blutgruppenunverträglichkeit, eine Hypoalbuminämie bzw. infektiöse oder autoimmune Erkrankungen des Fetus und/oder der Mutter. Die Ätiologie der Perikarderkrankungen der Mutter während der Schwangerschaft ist vielfältig, wobei die akute virale Perikarditis und Perikardergüsse im Rahmen systemischer autoimmuner Erkrankungen die häufigsten Ursachen darstellen. Selten findet man auch Perikardergüsse bei Schwangeren im Rahmen von Tumorerkrankungen oder einer Tuberkulose. Wenn starke präkordiale Schmerzen, Veränderungen im EKG und eine deutliche Beeinträchtigung der Belastungsfähigkeit auftreten, ist eine Klinikeinweisung unumgänglich. Therapie: Die meisten Perikarderkrankungen bei Schwangeren werden behandelt wie die von Nichtschwangeren, d.h. mit nichtsteroidalen antiinflammatorischen Medikamenten bei akuter Perikarditis, mit Antibiotika und ggf. einer Drainage bei eitrigen Perikardergüssen bzw. der Gabe von Kortikosteroiden bei autoimmunen Systemerkrankungen. Die Gabe von Colchicin ist während der Schwangerschaft kontraindiziert. Eine Perikardpunktion wird nur bei großen Perikardergüssen mit den klinischen Zeichen einer akuten Tamponade bzw. bei Verdacht auf Tuberkulose, infektiösen Erguss oder Tumorerkrankung durchzuführen sein. In diesen wenigen Fällen ist eine echokardiographisch gesteuerte Punktion angebracht, um eine Strahlenbelastung des Ungeborenen zu vermeiden. Eine Perikardektomie sollte nur bei perikardialer Konstriktion und schwerer bakterieller Infektion durchgeführt werden. Die Prozeduren Perikardpunktion und Perikardektomie allein haben, vom Interventions- bzw. Operationsrisiko abgesehen, keinen negativen, sondern eher einen günstigen prognostischen Einfluss auf die Schwangerschaft. Es gibt bislang keine ausreichenden Daten dafür, dass eine Perikardergussbildung in einer vorausgegangenen Schwangerschaft bei erneuter Gravidität zu einem Rezidiv führt. Liegen gleichzeitig allerdings eine linksventrikuläre Dilatation und Dysfunktion vor, ist, wie im Beitrag "Schwangerschaft und Kardiomyopathie" ausgeführt, nach den Empfehlungen der European Society of Cardiology (ESC) von einer erneuten Schwangerschaft abzuraten.     

Concurrent Accelerated Hyperfractionated Radiation Therapy and Carboplatin/etoposide in Patients With Malignant Glioma: Long-term break Results of A Phase II Study

Purpose: Feasibility, antitumor activity and toxicity of accelerated hyperfractionated radiation therapy (Acc Hfx RT) and concurrent carboplatin/etoposide (CBDCA/VP 16) chemotherapy were investigated in patients with malignant glioma. Material and methods: Seventy-nine patients with either glioblastoma multiforme (GBM) (n = 61) or anaplastic astrocytome (AA) (n = 18) entered into a phase II study on the use of Acc Hfx RT with 60Gy in 40 fractions in 20 treatment days over 4 weeks and concurrent CBDCA, 200mg/m², and VP 16, 200mg/m², both given once weekly during the RT course. Results: The median survival time for all 79 patients was 14 months (11 and 44 months for GBM and AA patients, respectively), while the 2- and 4-year survival was respectively 33% and 11% for all patients, 13% and 1.6% for GBM patients, and 100% and 44% for AA patients (p < 0.0001). The median time to progression for all patients was 12 months (9 and 40 months for GBM and AA, respectively), while the 2- and 4-year progression-free survival (PFS) was respectively 28% and 10% (all patients), 10% and 1.7% (GBM) and 89% and 39% (AA) (p < 0.0001). Multivariate analysis showed that age, performance status, and preoperative size of tumor influenced survival in GBM. Only 5 (6%) patients experienced grade 3 leukopenia and 6 (8%) patients experienced grade 3 thrombocytopenia. No late RT-induced toxicity was observed to date. Conclusions: Although Acc Hfx RT/CBDCA + VP 16 was feasible and little toxic, it failed to improve survival/progression-free survival over that obtained with other currently used regimens. These results do not justify the investigation of this regimen in a phase III trial.     

The enhancement of riboflavin-mediated photo-oxidation of doxorubicin by histidine and urocanic acid

PURPOSE: Previously we have shown that doxorubicin (Adriamycin, ADR) can be inactivated by light-excited riboflavin. The inactivation of the drug results from its direct oxidation by the excited triplet riboflavin in a type I photosensitization reaction, and 3-methoxysalicyclic acid is an ADR breakdown product. In the present study, we investigated the enhancement of this process by histidine and some other imidazole analogs. METHODS: ADR solutions containing various concentrations of riboflavin and other agents were exposed to 365 nm light for various time periods and then the absorbance spectrum of ADR was measured by a double beam spectrophotometer. These measurement were used to calculate the half-time of the ADR degradation process. The degraded ADR solutions were analyzed by HPLC. RESULTS: The rate of bleaching of ADR by light-excited riboflavin was enhanced in the presence of histidine in a concentration-dependent manner. This enhancement was more pronounced at higher riboflavin concentrations. Histidine also enhanced the riboflavin-mediated photobleaching of N,N-dimethyl-4-nitrosoaniline (RNO), a compound known to be resistant to oxidation by singlet oxygen but sensitive to oxidation by the trans-annular peroxide of histidine. RNO was found to block the histidine enhancement of the riboflavin-mediated photobleaching of ADR in a competitive manner. Among the imidazole analogs of histidine tested, urocanic acid was found to be the most efficient enhancer of the riboflavin-mediated photobleaching of ADR. Superoxide anion radicals which retard the oxidation of ADR were quenched by urocanic acid but not by histidine. It was shown that the oxidation of ADR by the trans-annular peroxide of histidine resulted in the formation of 3-methoxysalicylic acid. CONCLUSIONS: In contrast to singlet oxygen, the trans-annular peroxide, formed by the interaction of histidine and the singlet oxygen produced by photoexcited riboflavin, is an efficient oxidizer of ADR. The enhancement of the riboflavin-mediated photobleaching of ADR by histidine analogs depends on the rate of their conversion to a trans-annular peroxide and on the efficiency of these products in oxidizing ADR. However, for some analogs of histidine, as shown for urocanic acid, other mechanisms could also be involved. The presence of urocanic acid in the skin suggests that significant degradation of ADR could occur in the presence of biologically relevant concentrations of riboflavin if patients treated with ADR are exposed to sunlight. The finding that histidine also enhanced the degradation of ADR to 3-methoxysalicylic acid, suggests that the process of ADR oxidation by the trans-annular peroxides is similar to the direct oxidation of ADR by excited triplet riboflavin.     

Consanguinity and family history of cancer in children with leukemia and lymphomas.

BACKGROUND: In native population of the United Arab Emirates (UAE), the rate of consanguineous marriages is 50.5%. This study was designed to determine whether the rates of consanguinity and family history of cancer among the families of children with lymphoid malignancy are different from those in the general population. METHODS: The study comprised 117 patients from the whole of the country with acute lymphocytic leukemia (ALL) and Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), ranging in age from 2 to 14 years. The consanguinity rate in the study group was compared with the rate in the general population. To study family history of cancer, the authors matched patients with 117 controls. In a telephone interview, each mother was asked to provide data regarding the biologic relationship between her and her husband as well as that between both sets of grandparents; each was also asked whether any family relative had a cancer and, if so, of what type. RESULTS: Among the 69 ALL cases, 80% of families were consanguineous and 20% were nonconsanguineous. Among the 26 NHL and 22 HL cases, each group included 3 consanguineous families, 12% and 14%, respectively. The consanguinity rates for ALL, NHL, and HL were all significantly different from the 50.5% consanguinity rate in the UAE population (all three P values < 0.0001). The family history of cancer was more often positive in ALL patients than in controls (odds ratio, 2.14; confidence interval, 1.01--4.53). Overall and for each lymphoid malignancy, there was no difference in family history of cancer between consanguineous and nonconsanguineous groups of cases. CONCLUSIONS: The consanguinity rate in the families of patients with ALL is significantly higher and in those with NHL and HL significantly lower than that in the UAE population. The family history of cancer is more often positive among ALL cases than controls--consanguinity having no effect.     

Genetic association study of the P‐type ATPase ATP13A2 in late‐onset Parkinson's disease

A role of ATP13A2 in early‐onset Parkinsonism (EOP) has been proposed. Conversely, the contribution of this ATPase to late‐onset Parkinson's disease (PD) remains unexplored. We therefore conducted a case–control association study in this age‐of‐onset group with PD. The initial sample was of German origin and consisted of 220 patients with late‐onset PD (mean age of onset 60.1 years) and 232 age‐matched unrelated controls. Five single nucleotide polymorphisms (SNPs) covering ATP13A2 and its common haplotypes were genotyped. The overall association results in this sample were negative. Interestingly, gender stratification gave a positive result for SNP rs11203280 (P_UNC = 0.016) in men. This result could not be reproduced in a replication sample of German and Serbian origin composed of 161 patients with late‐onset PD (mean age of onset 51.7 years) and 150 age‐ and ethnic‐matched controls. In conclusion, we found no consistent evidence for an association between ATP13A2 and late‐onset PD. © 2008 Movement Disorder Society     

Latissimus dorsi-scapula free flap for reconstruction of defects following radical maxillectomy with orbital exenteration.

A total of 21 patients with latissimus dorsi-scapula free flap reconstruction immediately following radical maxillectomy together with orbital exenteration are presented. Orbital exenteration was performed in all patients due to tumour invasion at the time of diagnosis. There was no total flap failure. Two tissue components subdivided into separate flap units with individual vascular pedicles linked by a single vascular source provide an ideal reconstructive solution for massive defects of the mid-face and orbit. Separate arcs of rotation of each flap unit permit greater mobility necessary for complex three-dimensional reconstruction. A vertically positioned angle of the scapula enables simultaneous reconstruction of the malar eminence and alveolar ridge whereas spontaneous intraoral epithelialisation of the latissimus dorsi muscle requires no additional procedure. For these reasons, in our opinion, combined latissimus dorsi-scapula free flap should be considered the first choice in reconstruction of defects following total maxillectomy with orbital exenteration.     

Procalcitonin in preoperative diagnosis of abdominal sepsis

Background and aims The present study attempted to identify the diagnostic significance of procalcitonin (PCT) in acute abdominal conditions as well as the range of concentrations relating to diagnosis of abdominal sepsis. Materials and methods This was prospective clinical study. The study included 98 consecutive patients with acute abdominal conditions, divided in sepsis and systemic inflammatory response syndrome (SIRS) group. Results PCT concentrations on admission were significantly higher in the sepsis group than in the SIRS group (median [interquartile range] 2.32 [7.41] vs 0.45 ng/ml [2.62]). A cutoff value of 1.1 ng/ml yielded 72.4% sensitivity and 62.5% specificity. In a group of patients with abdominal symptoms lasting for more than 24 h, a cut-off value of 1.1 ng/ml yielded higher sensitivity (82.9%) and higher specificity (77.3%). Conclusion Our results suggest that PCT measurements may be useful for early, preoperative diagnosis of abdominal sepsis.