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31.
JE McMICHAEL 《Journal of paediatrics and child health》1997,33(1):1-3
An understanding of the neurodevelopmental outcome of long-term survivors of neonatal intensive care is essential for the informed management of preterm or high risk infants. This annotation looks at the current status of neonatal follow-up services in Australasia and highlights problems in the collection and interpretation of data. It suggests that we should work towards achieving a consensus on standard definitions and test regimes and on national data collection. 相似文献
32.
L Patel PE Clayton ME Jenney JE Ferguson TJ David 《Archives of disease in childhood》1997,76(6):505-508
Cross sectional studies have reported impaired growth in children with atopic dermatitis. If this growth impairment is irreversible, it would be expected to adversely influence final height attainment. The standing heights and other anthropometric parameters were assessed in 35 adults with onset of atopic dermatitis before 5 years of age and a control group of 35 adults with adult onset contact dermatitis or psoriasis. There was no significant difference in the standing height SD score, mid-parental height SD score, sitting height SD score, subischial leg length SD score, nor body mass index between the atopic dermatitis and control groups. The standing height SD score was not significantly different among: (a) patients with atopic dermatitis affecting less than 50% of their body surface area and those with greater than 50% affected; (b) patients using the four different potency topical corticosteroids; and (c) patients with atopic dermatitis without asthma and those with coexisting asthma. It is concluded that short stature is not a feature of our group of adult patients with onset of atopic dermatitis before 5 years of age, continuing into adulthood, and severe enough to require specialist care. This suggests that if growth impairment occurs in childhood, it is likely to be temporary and reversible. 相似文献
33.
Hydrogen peroxide inhibits gap junctional intercellular communication in glutathione sufficient but not glutathione deficient cells 总被引:7,自引:5,他引:7
Cell to cell communication via gap junctions is essential in the
maintenance of the homeostatic balance of multicellular organisms. Aberrant
intercellular gap junctional communication (GJIC) has been implicated in
tumor promotion, neuropathy and teratogenesis. Oxidative stress has also
been implicated in similar pathologies such as cancer. We report a
potential link between oxidative stress and GJIC. Hydrogen peroxide, a
known tumor promoter, inhibited GJIC in WB-F344 rat liver epithelial cells
with an I50 value of 200 microM. Inhibition of GJIC by H2O2 was reversible
as indicated by the complete recovery of GJIC with the removal of H2O2 via
a change of fresh media. Free radical scavengers, such as t-butyl alcohol,
propylgallate, and Trolox, did not prevent the inhibition of GJIC by H2O2,
which indicated that the effects of H2O2 on GJIC was probably not a
consequence of aqueous free radical damage. The depletion of intracellular
GSH reversed the inhibitory effect of H2O2 on GJIC. The treatment of
glutathione- sufficient cells with H2O2 resulted in the
hyperphosphorylation of connexin43, which is the basic subunit of the
hexameric gap junction protein, as determined by Western blot analysis.
TPA, a well-known tumor promoter, also inhibits GJIC via
hyperphosphorylation of GJIC, which is a result of protein kinase-C
activation. However, H2O2 also induced hyperphosphorylation in
GSH-deficient cells that had normal rates of GJIC. Therefore, the mechanism
of GJIC inhibition must be different from the TPA-pathway and involves GSH.
相似文献
34.
Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon 总被引:1,自引:1,他引:1
We have examined whether dietary polyamines influence the formation and
initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in
rat colon. Effects of a combination of dietary polyamines at three dose
levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g;
spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied
in animals in two different experimental situations: animals treated with
AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a
specific inhibitor of endogenous polyamine synthesis. In both experimental
situations, dietary polyamines enhanced the growth of ACF, expressed as the
number of large ACF (foci with three or more aberrant crypts, ACF > or =
3), whereas the formation of ACF, expressed as the number of ACF, was
apparently not altered. In animals treated with AOM alone, maximal growth
enhancing effect on ACF was nearly obtained with the median level of
dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO
reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of
DFMO was counteracted by dietary polyamines in a dose- dependent manner,
and it was abolished at the highest level of polyamines. In conclusion, it
was demonstrated that dietary polyamines are able to enhance the growth of
AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused
inhibition of ACF growth, probably by compensating for the DFMO-reduced
endogenous polyamine synthesis.
相似文献
35.
Hansen LA; Malarkey DE; Wilkinson JE; Rosenberg M; Woychik RE; Tennant RW 《Carcinogenesis》1998,19(10):1837-1845
We previously reported that papillomas can arise from the follicular
epithelium of v-Ha-ras transgenic TGxAC mice. Since the viable-yellow
mutation (A(vy)) of the mouse agouti gene which regulates coat color
pigmentation by acting within the micro-environment of the hair follicle
has been shown to function as a tumor promoter in the liver, we
hypothesized that it may also play a role in TGxAC skin tumorigenesis.
Endogenous agouti protein product was detected in the outer root sheath of
anagen hair follicles following plucking of the hair shaft, but not in the
interfollicular epithelium, in TGxAC mice on an FVB/N genetic background.
It was also detected in papillomas from these mice produced by
12-O-tetradecanoylphorbol-13-acetate (TPA) treatment or plucking.
Expression of the A(vy) allele in the v-Ha-ras transgenic TGxAC mouse line
results in an approximately 2-fold increase in papilloma development
compared with controls which did not carry the A(vy) allele following
twice-weekly treatment with 1.25, 2.5 or 5.0 microg TPA. In addition,
TPA-treated, papilloma-bearing F1 mice which carried the A(vy) allele, but
not F1 mice which did not carry the A(vy) allele, exhibited a syndrome of
humoral hypercalcemia mediated by parathyroid hormone-related protein
(PTHrP) that led to weight loss, hypercalcemia and hypophosphatemia. Thus,
we conclude that the A(vy) allele can influence the development of skin
tumors and PTHrP-mediated humoral hypercalcemia in v-Ha-ras transgenic
TGxAC mice.
相似文献
36.
Yu Sun Hayley Reynolds Darren Wraith Scott Williams Mary E. Finnegan Catherine Mitchell Declan Murphy Martin A. Ebert Annette Haworth 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2017,40(1):39-49
The performance of a support vector machine (SVM) algorithm was investigated to predict prostate tumour location using multi-parametric MRI (mpMRI) data. The purpose was to obtain information of prostate tumour location for the implementation of bio-focused radiotherapy. In vivo mpMRI data were collected from 16 patients prior to radical prostatectomy. Sequences included T2-weighted imaging, diffusion-weighted imaging and dynamic contrast enhanced imaging. In vivo mpMRI was registered with ‘ground truth’ histology, using ex vivo MRI as an intermediate registration step to improve accuracy. Prostate contours were delineated by a radiation oncologist and tumours were annotated on histology by a pathologist. Five patients with minimal imaging artefacts were selected for this study. A Gaussian kernel SVM was trained and tested on different patient data subsets. Parameters were optimised using leave-oneout cross validation. Signal intensities of mpMRI were used as features and histology annotations as true labels. Prediction accuracy, as well as area under the curve (AUC) of the receiver operating characteristics (ROC) curve, were used to assess performance. Results demonstrated the prediction accuracy ranged from 70.4 to 87.1% and AUC of ROC ranged from 0.81 to 0.94. Additional investigations showed the apparent diffusion coefficient map from diffusion weighted imaging was the most important imaging modality for predicting tumour location. Future work will incorporate additional patient data into the framework to increase the sensitivity and specificity of the model, and will be extended to incorporate predictions of biological characteristics of the tumour which will be used in bio-focused radiotherapy optimisation. 相似文献
37.
CJ Stewart ECL Marrs S Magorrian A Nelson C Lanyon JD Perry ND Embleton SP Cummings JE Berrington 《Acta paediatrica (Oslo, Norway : 1992)》2012,101(11):1121-1127
Aim: To describe gut colonization in preterm infants using standard culture and 16S gene rRNA profiling, exploring differences in healthy infants and those who developed NEC/late onset sepsis (LOS). Methods: Ninety‐nine stools from 38 infants of median 27‐week gestation were cultured; 44 stools from 27 infants had their microbial profiles determined by 16S. Ordination analyses explored effects of patient variables on gut communities. Results: Standard microbiological culture identified a mean of two organisms (range 0–7), DGGE 12 (range 3–18) per patient. Enterococcus faecalis and coagulase negative staphylococci (CONS) were most common by culture (40% and 39% of specimens). Meconium was not sterile. No fungi were cultured. Bacterial community structures in infants with NEC and LOS differed from healthy infants. Infants who developed NEC carried more CONS (45% vs 30%) and less Enterococcus faecalis (31% vs 57%). 16S identified Enterobacter and Staphylococcus presence associated with NEC/LOS, respectively. Conclusions: Important differences were found in the gut microbiota of preterm infants who develop NEC/LOS. The relationship of these changes to current practices in neonatal intensive care requires further exploration. 相似文献
38.
The first permanent molar (FPM) is commonly subject to significant compromise which may arise due to caries or endodontic complication, or from developmental anomalies such as hypoplasia. Compromised teeth with questionable prognosis may result in short and long-term clinical dilemmas. This review article highlights the factors that require careful consideration when a compromised FPM is detected and the importance of timely FPM extraction. Several clinical cases are described in detail to discuss possible treatment options from the orthodontic perspective. 相似文献
39.
The efficacy and outcome of bone marrow transplantation therapy following lethal irradiation were examined in syngeneic mice that had a hereditary macrocytic anemia (an/an) or were genotypically normal (+/+). Successful RBC and WBC replacement, based on blood cell parameters and donor genetic markers, were observed in all combinations of transplant therapy. Nevertheless, the an/an mice died prematurely several months after treatment, whether they received +/+ or an/an marrow cells. In contrast, the +/+ recipients of either +/+ or an/an marrow cells survived for at least 1 year after transplantation. Premature death of the an/an mice was associated with lymphopenia, anemia, kidney lesions, and severe pathogen-free pneumonitis. On the basis of our results, we hypothesize that the premature deaths of an/an mice are caused by a kind of chronic irradiation damage to which an/an mice are especially susceptible. 相似文献
40.
The widespread assumption that cytoplasts generated from human polymorphonuclear leukocytes (PMNs) are vesicles consisting solely of cytoplasm surrounded by plasma membrane and devoid of granule activity remains to be tested. PMN cytoplasts were prepared by centrifugation of intact cells on a Ficoll step gradient in the presence of cytochalasin B. Two granule membrane markers, Mol, a fluorometrically detectable antigen, and cytochrome b, both of which have been shown to translocate to the plasma membrane during granule release, were compared for their activity in cytoplasts and intact PMNs. We found that the amount of Mol detected on the plasma membrane of intact PMNs, as compared with other membrane markers (such as antigens LFA-1 and beta 2m), increased 1.6- fold upon exposure of PMNs to Ficoll plus cytochalasin B prior to centrifugation. Another twofold increase in Mol expression occurred upon cytoplast preparation. Release of the granule enzymes, vitamin B12- binding protein, and lysozyme were also followed and correlated well (r = .78 and .92) with the amount of Mol antigen present on the cell surface. Cytochrome b was also found to be higher (1.4-fold) on plasma membranes isolated from cytoplasts than on plasma membranes isolated from intact control cells. These results indicate that some fusion of granule membranes and plasma membranes occurred during treatment of PMNs with Ficoll plus cytochalasin b and during cytoplast preparation. 相似文献