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31.
Aesthesiometry of the cornea after refractive corneal surgery] 总被引:1,自引:0,他引:1
M Kohlhaas J Draeger A B?hm M Lombardi M Abbondanza M Zuppardo M G?rne 《Klinische Monatsbl?tter für Augenheilkunde》1992,201(4):221-223
The corneal sensibility was examined with the aesthesiometer of Draeger in 41 patients after refractive corneal surgery, 31 patients after radial keratotomy, 5 after epikeratophakia, 5 after excimer laser ablation. It could be shown that after radial corneal incisions the sensibility remains normal. After epikeratophakia the corneal sensibility is asensible even 3 years after operation. The lenticle periphery shows an increase of sensibility after 6 months. Excimer patients with "haze" showed a significant hyposensibility in the centre. The central sensibility showed normal values after a normal corneal wound healing. 相似文献
32.
P Gaetani R Rodriguez y Baena F Marzatico D Lombardi R Knerich P Paoletti 《Neurosurgery》1991,28(6):853-7; discussion 857-8
The specific mechanism underlying the genesis of vasogenic brain edema is still debated: the role of arachidonic acid is considered extremely important, as it is a possible activator of self-maintaining reactions enhancing the release of vasoactive and cytotoxic compounds. The relationship between arachidonic acid metabolism and brain edema has been studied primarily in brain tissue samples or in the extracellular fluid, whereas the residual capacity of perilesional tissue to synthesize and release eicosanoids has not been investigated. In the present study, perilesional samples of brain tissue were available from 4 patients operated on for brain metastasis, from 8 patients who had malignant neuroepithelial tumors, from 4 with meningiomas, and from 5 with subarachnoid hemorrhage. A brain edema index was calculated from the preoperative computed tomographic scan. The "ex vivo" method allowed determination of the residual capacity of endogenous arachidonic acid metabolism. The edema index is significantly higher in patients with brain metastasis (6.5 +/- 0.8) and neuroepithelial tumors (3.6 +/- 0.2) than in those with meningiomas (1.5 +/- 0.06), subarachnoid hemorrhage (1.7 +/- 0.18), and in controls. In patients with metastatic and neuroepithelial tumors there is a significant correlation between peritumoral brain edema and the capacity to synthesize leukotriene C4 (P less than 0.05); the capacity to synthesize leukotriene C4 is also significantly elevated after subarachnoid hemorrhage (13.91 +/- 2.6 ng/ml of incubation medium) when compared with control cases (5.56 +/- 0.91). The capacity to synthesize prostacyclin is significantly higher in patients with brain metastasis than in those with neuroepithelial tumors and meningiomas (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
33.
34.
Objective: To identify factors that influence a woman's decision to breast-feed.
Methodology: Five hundred and fifty-six women were recruited from the maternity wards of two Perth hospitals. Data were collected from a self-administered questionnaire completed by participants prior to discharge. Logistic regression analysis was used to determine factors influencing the initiation of breast-feeding.
Results: At discharge from hospital 83.8% of women were breast-feeding, including 6% who were giving complementary formula feeds. After controlling for potentially confounding demographic and biomedical factors, the father's reported preference for breast-feeding was found to be the most important factor influencing a woman's decision to breast-feed (OR 10.18).
Conclusion: Fathers participate in and influence the choice of infant feeding method and should be included in breast-feeding discussions. 相似文献
Methodology: Five hundred and fifty-six women were recruited from the maternity wards of two Perth hospitals. Data were collected from a self-administered questionnaire completed by participants prior to discharge. Logistic regression analysis was used to determine factors influencing the initiation of breast-feeding.
Results: At discharge from hospital 83.8% of women were breast-feeding, including 6% who were giving complementary formula feeds. After controlling for potentially confounding demographic and biomedical factors, the father's reported preference for breast-feeding was found to be the most important factor influencing a woman's decision to breast-feed (OR 10.18).
Conclusion: Fathers participate in and influence the choice of infant feeding method and should be included in breast-feeding discussions. 相似文献
35.
36.
37.
Abril N; Luque-Romero FL; Prieto-Alamo MJ; Rafferty JA; Margison GP; Pueyo C 《Carcinogenesis》1997,18(10):1883-1888
Here we confirm and extend our previous studies demonstrating that the
mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is
markedly enhanced (not prevented) in bacteria expressing the O6-
alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli
ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt
ATase sensitizes the bacteria to the lethal effects of these carcinogens,
suggesting that one or more of the potentially mutagenic lesions induced by
DBE and DBM in the presence of Ogt has additional lethal capacity. We
further demonstrate that the sensitization to both lethality and
mutagenesis by DBE and DBM is a property shared by other DNA
alkyltransferases. This objective was accomplished by quantifying the
induction of mutations and lethal events in ogt- ada- E. coli expressing an
exogenous bacterial or mammalian ATase from a multicopy plasmid. Mammalian
recombinant ATases enhanced the lethal and mutagenic actions of DBE and
suppressed the lack of sensitivity of the vector- transformed bacteria to
DBM. In most cases the order of effectiveness of the ATases ranked: murine
> human > Ogt > rat. Further comparisons included the full-length
Ada ATase from E. coli and a truncated Ada version (T-ada) that retains the
O6-methylguanine binding domain of the protein. The full-length Ada ATase
was effective in enhancing the lethality but not the mutagenicity induced
by DBE and DBM. The T-ada ATase provided less sensitization than Ada to
lethality by DBE, but of the three bacterial ATases T-ada yielded the
highest sensitization to mutagenesis by this compound. T-ada and Ada ATases
were in general less effective than the mammalian versions, with the
exception of the rat recombinant ATase. The effectiveness of the different
mammalian and bacterial ATases in promoting the deleterious actions of
dibromoalkanes was compared with the effectiveness of these proteins in
suppressing the lethal and mutagenic effects induced by
N-nitroso-N-methylurea. The ability to sensitize E. coli to the lethal and
mutagenic effects of DBE and DBM seems restricted to DNA alkyltransferase,
since overexpression of thioredoxin (Trx) or glutaredoxin (Grx1) in ogt-
ada- cells showed no effect, in spite of the reported potential of
bioactive dihaloethane- derived species to alkylate Trx.
相似文献
38.
Dibenzo[a,l]pyrene-induced DNA adduction, tumorigenicity, and Ki-ras oncogene mutations in strain A/J mouse lung 总被引:1,自引:0,他引:1
Prahalad AK; Ross JA; Nelson GB; Roop BC; King LC; Nesnow S; Mass MJ 《Carcinogenesis》1997,18(10):1955-1963
Dibenzo[a,l]pyrene (DB[a,l]P), an environmental polycyclic aromatic
hydrocarbon, is the most potent carcinogen ever tested in mouse skin and
rat mammary gland. In this study, DB[a,l]P was examined for DNA adduction,
tumorigenicity, and induction of Ki-ras oncogene mutations in tumor DNA in
strain A/J mouse lung. Groups of mice received a single i.p. injection of
0.3, 1.5, 3.0, or 6.0 mg/kg DB[a,l]P in tricaprylin. Following treatment,
DNA adducts were measured at times between 1 and 28 days, while tumors were
counted at 250 days and analyzed for the occurrence of point mutations in
codons 12 and 61 of the Ki-ras oncogene. DB[a,l]P in strain A/J mouse lung
induced six major and four minor DNA adducts. Maximal levels of adduction
occurred between 5 and 10 days after injection followed by a gradual
decrease. DB[a,l]P-DNA adducts in lung tissue were derived from both anti-
and syn-11,12- dihydroxy-13,14-epoxy-
11,12,13,14-tetrahydrodibenzo[a,l]pyrene (DB[a,l]PDE) and both
deoxyadenosine (dAdo) and deoxyguanosine (dGuo) residues in DNA as revealed
by cochromatography. The major adduct was identified as a product of the
reaction of an anti-DB[a,l]PDE with dAdo in DNA. DB[a,l]P induced
significant numbers of lung adenomas in a dose- dependent manner, with the
highest dose (6.0 mg/kg) yielding 16.1 adenomas/mouse. In
tricaprylin-treated control animals, there were 0.67 adenomas/mouse. Based
on the administered dose, DB[a,l]P was more active than other environmental
carcinogens including benzo[a]pyrene. As a function of time-integrated DNA
adduct levels, DB[a,l]P induced lung adenomas with about the same potency
as other PAHs, suggesting that the adducts formed by DB[a,l]P are similar
in carcinogenic potency to other PAHs in the strain A/J mouse lung model.
Analysis of the Ki- ras mutation spectrum in DB[a,l]P-induced lung tumors
revealed the predominant mutations to be G-->T transversions in the
first base of codon 12, A-->G transitions in the second base of codon
12, and A-->T transversions in the second or third base of codon 61,
concordant with the DNA adduct profile.
相似文献
39.
Assessment of the mutagenicity of dichloroacetic acid in lacI transgenic B6C3F1 mouse liver 总被引:2,自引:0,他引:2
Dichloroacetic acid (DCA) is a chlorination byproduct found in finished
drinking water. When administered in drinking water this chemical has been
shown to produce hepatocellular adenomas and carcinomas in B6C3F1 mice over
the animal's lifetime. In this study, we investigated whether mutant
frequencies were increased in mouse liver using treatment protocols that
yielded significant tumor induction. DCA was administered continuously at
either 1.0 or 3.5 g/l in drinking water to male transgenic B6C3F1 mice
harboring the bacterial lacI gene. Groups of five or six animals were
killed at 4, 10 or 60 weeks and livers removed. At both 4 and 10 weeks of
treatment, there was no significant difference in mutant frequency between
the treated and control animals at either dose level. At 60 weeks, mice
treated with 1.0 g/l DCA showed a 1.3-fold increase in mutant frequency
over concurrent controls (P = 0.05). Mice treated with 3.5 g/l DCA for 60
weeks had a 2.3-fold increase in mutant frequency over the concurrent
controls (P = 0.002). The mutation spectrum recovered from mice treated
with 3.5 g/l DCA for 60 weeks contained G:C-->A:T transitions (32.79%)
and G:C-->T:A transversions (21.31%). In contrast, G:C-->A:T
transitions comprised 53.19% of the recovered mutants among control
animals. Although only 19.15% of mutations among the controls were at T:A
sites, 32.79% of the mutations from DCA-treated animals were at T:A sites.
This is consistent with the previous observation that the proportion of
mutations at T:A sites in codon 61 of the H-ras gene was increased in
DCA-induced liver tumors in B6C3F1 mice. The present study demonstrates
DCA-associated mutagenicity in the mouse liver under conditions in which
DCA produces hepatic tumors.
相似文献
40.
F Buzi A Pilotta D Dordoni A Lombardi S Zaglio P Adlard 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(11):1138-1145
This prospective study sought to evaluate the role of pelvic ultrasonography in differentiating between various types of pubertal precocity. A control group of 117 normal girls (aged 1.1-15.6) was studied and compared with 87 girls with premature sexual maturation (aged 1.1-9.2y). Of these patients 19 had central precocious puberty (CPP), 48 had isolated premature thelarche (IPT) and 20 had premature adrenarche (IPA) Pelvic ultrasound variables evaluated were: (i) uterus: longitudinal diameter (uterine length), cross-sectional area (CSA) and fundo-cervical ratio; and (ii) ovaries: volume and morphology. Ovarian morphology was subdivided in 6 different appearances: solid, microcystic, paucicystic, multicystic, macrocystic, and major isolated cyst. In normal control girls, uterine length and CSA increased with age, although no cut-off values could be defined between different age ranges, and they were correlated with breast stage; fundo-cervical ratio was stable through childhood and increased after age 9. Ovarian volume was significantly greater in pubertal girls with breast stage 2 than in those with only pubic and/or axillary hair. There was a clear predominance of solid ovarian appearances in the age range 2-7, with the multicystic appearance being seen only after age 7, a minority being macrocystic. After age 10 all the different patterns were observed, and after age 13 the frequency of a macrocystic pattern increased. Significantly more mature ovarian appearances were observed in subjects with breast development compared with those without, independently of the presence of pubic hair. Patients with IPT had no significant differences in pelvic ultrasound measurements when compared with age-matched controls. All the different morphological ovarian appearances were observed in IPT, in contrast to age-matched controls, where only the less mature patterns (solid, micro- and paucicystic) were seen. Patients with CPP had significantly more mature patterns of ovarian morphology compared with age-matched controls, but did not differ from pubertal pre-menarcheal controls. Those patients with IPA differed from age-matched controls only in having significantly greater uterine length and CSA. Comparison of the pelvic ultrasound parameters between patient groups (IPT, CPP, IPA) and age-matched controls revealed significantly higher values in CPP for uterine length, uterine CSA and ovarian volume. Ovarian volume was also greater in IPT than in IPA. Ovarian morphology was significantly different in patients (IPT, CPP, IPA) compared with age-matched controls, but none of the ovarian morphological appearances was exclusive to a single condition. In conclusion: (i) pelvic ultrasound parameters increase progressively from birth to maturity, but no clear cut-off values can be established between age ranges; (ii) pelvic ultrasound variables reach adult values during puberty, with differences in the timing that may reflect geographical variations; (iii) the multicystic ovarian appearance occurs just before the onset of puberty; (iv) pelvic ultrasonography cannot always differentiate clearly between different disturbances of puberty and therefore cannot supersede other observations and investigations in the evaluation of pubertal disorders; and (v) in this study we propose a more detailed pelvic ultrasound terminology that can avoid apparent confusion in defining ovarian ultrasound appearance. 相似文献