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81.
Erythropoiesis is distinct at each stage of ontogeny. 总被引:3,自引:0,他引:3
In vitro erythropoiesis from fetuses, newborn infants, and adults was compared in methyl cellulose cultures. Fetal and newborn blood erythroid colony formation tended to be more sensitive to erythropoietin than adult. The day of maximal colony formation was earlier in fetal than in newborn or adult cultures. The number of colonies/100,000 mononuclear cells on d 13 of culture and on the day of peak growth was highest in fetal, intermediate in newborn, and lowest in adult cultures. Burst forming units-erythroid/mL of blood on culture d 13 and the day of peak growth were similar in fetuses and newborns, and both were significantly greater than in adults. The proportional synthesis of gamma-globin in fetal colonies was 2-fold greater than in newborn colonies, and 6-fold greater than in adult colonies. Thus, fetal, newborn, and adult erythroid progenitor cultures are each unique with regard to erythropoietin sensitivity, growth time course, number of erythroid colonies, and the proportion of gamma-globin synthesis. 相似文献
82.
Generalized singular value decomposition for comparative analysis of genome-scale expression data sets of two different organisms
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Alter O Brown PO Botstein D 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(6):3351-3356
We describe a comparative mathematical framework for two genome-scale expression data sets. This framework formulates expression as superposition of the effects of regulatory programs, biological processes, and experimental artifacts common to both data sets, as well as those that are exclusive to one data set or the other, by using generalized singular value decomposition. This framework enables comparative reconstruction and classification of the genes and arrays of both data sets. We illustrate this framework with a comparison of yeast and human cell-cycle expression data sets. 相似文献
83.
Blanche P Alter 《Pediatric transplantation》2005,9(S7):81-86
Abstract: Patients with Fanconi's Anemia (FA) have high rates of congenital physical abnormalities, bone marrow failure, leukemia, and solid tumors. Stem cell transplant (SCT) is often effective in curing bone marrow failure, but high-risk patients, particularly those whose donor is not a human leukocyte antigen matched sibling, are vulnerable to early mortality from transplant-related complications. Long-term survivors of SCT have risks of solid tumors (particularly of the oral cavity), which are even higher than the already high 'baseline' risk of neoplasia in untransplanted FA patients. In this group, the major types of cancer are head and neck squamous cell carcinomas, and gynecologic malignancies. Rapid evaluation of new SCT preparative regimens would be useful in improving both short-term and long-term results. 相似文献
84.
M Size ES Borgstein HJ Haisma 《Malawi medical journal : the journal of Medical Association of Malawi》2005,17(1):12-14
The intensive care unit at Queen Elizabeth Central Hospital (QECH) has 4 beds and offers level 2 care. A retrospective audit of all admissions to the unit during 2002 was carried out. There were a total of 339 admissions giving a bed occupancy rate of 82 %. Surgical patients made up 81 % of admissions. 45% of all admissions were ventilated. Overall mortality was 38%. Ventilated patients had a mortality of 71% compared with 10% for non-ventilated. Data are also presented for mortality within the surgical and paediatric surgical admissions. 相似文献
85.
How is Creutzfeldt-Jakob disease acquired? 总被引:1,自引:0,他引:1
Alter M 《Neuroepidemiology》2000,19(2):55-61
Creutzfeldt-Jakob disease (CJD) is one of several related disorders collectively called prion diseases. These disorders affect man and animals and are now known to be caused by the abnormal configuration of a naturally occurring protein, PrP(c). By mechanisms still not well understood, this natural protein is converted into a pathologic variant, PrP(sc). The disease is 'acquired' spontaneously perhaps by posttranslational conversion of a PrP(c) into a PrP(sc) population. This sporadic form of CJD has been reported worldwide with a frequency of 1/million. Other modes of acquisition include the following: ingestion of brain tissue from deceased victims through ritual cannibalism at burial ceremonies formerly (and no longer) practiced by New Guinea Highlanders; iatrogenically, through corneal transplants from infected donors, inoculation of human growth hormone and gonadotropin prepared from infected human pituitary glands; from inadequately sterilized depth electrodes introduced neurosurgically into the brain during workups of patients with epilepsy, and applications of infected dura mater in neurosurgical procedures. Most recently, an infected bovine source (bovine spongiform encephalopathy) has been implicated and produces a new variant of CJD. Clusters of CJD in families in some populations have been recognized which are inherited in Mendelian fashion. These clusters are related to mutations of the PRNP gene in specific codons (e.g. codon 200). Homozygosity for these mutations increases the chances of manifesting the disease. Other potential methods of acquisition, such as by blood transfusion, surgical sutures, tonometers, consumption of hog brain or other organs and tissue, remain unproven. 相似文献
86.
87.
Kroese ED; Dortant PM; van Steeg H; van Oostrom CT; van der Houven van Oordt CW; van Kranen HJ; de Vries A; Wester PW; van Kreijl CF 《Carcinogenesis》1997,18(5):975-980
E mu-pim-1 transgenic mice are predisposed to develop lymphomas. Due to
their low spontaneous tumour incidence and their increased sensitivity
towards the lymphomagen ethylnitrosourea these mice may present an
interesting model for short-term carcinogenicity testing. Here, we report
on the further exploration of this transgenic mouse model with two
additional carcinogens known to have, among others, the
lymphohaematopoietic system as target, i.e. benzo[a]pyrene (B[a]P) and
12-O-tetradecanoylphorbol-13-acetate (TPA). B[a]P, given three times a week
(by gavage) for 13 weeks at 4.3, 13 or 39 mg/kg body weight, resulted in a
dose-related increase in lymphomas up to a 90% incidence in E(mu)-pim-1
mice during the observation period of 40 weeks. B[a]P also induced tumours
of the forestomach within this observation period, though at a lower
incidence and apparently equally effective in wildtype and transgenic mice.
TPA, on the other hand, was unable to induce lymphomas (or tumours in any
other organ) in either transgenic or wildtype animals within the
observation period of 44 weeks, when applied dermally at the maximum
tolerated dose of 3 microg/mouse, twice a week for 35 weeks. Molecular
analysis showed that B[a]P-induced lymphomas in transgenic mice were of
T-cell origin, 80% of which had elevated levels of c-myc expression. None
of the lymphomas had increased N-myc expression and mutation analysis of
the ras-gene family revealed a K-ras mutation in only one out of eight
tumours investigated. Also, none of the lymphomas showed aberrant
expression of p53 as determined by immunohistochemistry. It is concluded
that the E mu-pim-1 mouse model will not be very suitable for short-term
carcinogenicity testing in general: only genotoxic chemicals that have the
lymphohaematopoietic system as target for carcinogenesis in wild- type
mice, appear to be efficiently identified.
相似文献
88.
Mucormycosis is a rare fungal infection of childhood, occurring mainly in
patients with chronic illnesses such as diabetes and malignancies. The
fungus seldom grows in culture and confirmation of the diagnosis depends on
histologic examination of infected tissues. To date, the reported natural
history of the disease has been rapid progression and a fatal outcome.
Therefore, the importance of early diagnosis by tissue biopsy and early
treatment with surgical debridement and systemic antifungal therapy cannot
be overemphasized. The pulmonary system is the most common site for
mucormycosis in patients with leukemia. We report what we believe to be the
first successfully treated case of isolated muscular mucormycosis occurring
in a child with biphenotypic acute leukemia. The diagnosis was made
promptly by tissue examination at the time of surgical debridement. The
patient was also given systemic amphotericin-B therapy.
相似文献
89.
NC de Bruin KA van Velthoven M de Ridder T Stijnen RE Juttmann HJ Degenhart HK Visser 《Archives of disease in childhood》1996,74(5):386-399
Data on body composition in conjunction with reference centiles are helpful in identifying the severity of growth and nutritional disorders in infancy and for evaluating the adequacy of treatment given during this important period of rapid growth. Total body fat (TBF) and fat-free mass (FFM) were estimated from total body electrical conductivity (TBEC) measurements in 423 healthy term Caucasian infants, aged 14-379 days. Cross sectional age, weight, and length related centile standards are presented for TBF and FFM. Centiles were calculated using Altman's method, based on polynomial regression and modelling of the residual variation. The TBF percentage steeply increased during the first half year of life, and slowly declined beyond this age. Various simple TBEC derived anthropometric prediction equations for TBF and FFM are available to be used in conjunction with these standards. Regression equations for the P50 and the residual SD, depending on age, weight, or length, are provided for constructing centile charts and calculating standard deviation scores. 相似文献
90.