共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
I Blickstein M Manor R Levi R Goldchmit A Weissman 《Canadian Metallurgical Quarterly》1995,50(3):253-255
OBJECTIVE: To establish the relationship between the fetal ponderal index and birth weight discordance in twins. METHOD: The fetal ponderal index (estimated fetal weight divided by femur length3) was calculated in 86 pairs of twins delivered within 2 weeks of the last sonography and analyzed in relation to birth weight discordance. RESULTS: A weak but significant correlation between fetal ponderal index and birth weight (r = 0.26, P < 0.0007) but no correlation with gestational age (r = 0.035, P = 0.65) were found. Members of concordant pairs (< 15% birth weight difference) had a significantly higher fetal ponderal index compared with members of mildly (15-25%) discordant pairs (P < 0.02), but not as compared with members of severely discordant (> 25%) pairs. CONCLUSION: The characteristics of the fetal ponderal index in twins are similar to those in singletons. Fetal size seems to be diminished in severe but not in mild discordants. However, in its present form, the fetal ponderal index is a poor predictor of discordant growth and therefore should be employed cautiously in twin gestations. 相似文献
3.
A phasic program of femoral nerve stimulation was used to reduce refractory knee flexion contractures in five patients. In one, rectus femoris was tenotomized before starting stimulation to reduce hip flexion contracture. Muscle biopsies were performed before and after 5 to 12 weeks of intermittent stimulation at separated sites on the same muscle. In the four patients where muscle contraction was isometric, type I fibers increased 3.7%, 6.4%, 48.4%, anand 30.4%, respectively. Both fiber types in each patient showed an increase in size ( p less than .001). In the tenotomized muscle, where contraction was isotonic at a shortened length, the proportion of type I fibers decreased from 40.2% to 25.4%, and their mean diameter also decreased (p less than .001). These observations suggest that the physical conditions of contraction may be more important than the pattern of neuronal discharge in determining the metabolic profile of human muscle fibers. 相似文献
4.
5.
OBJECTIVE: To investigate the relationship between fetal intrauterine growth retardation and anticardiolipin antibodies. METHODS: Serum anticardiolipin antibodies were detected with ELISA method in 5,330 cases of normal gravidas. Meanwhile, the observation of immunocomplex depositions in placentas in cases of positive anticardiolipin antibodies (ACA) were observed by immunofluorescence examination. RESULTS: The positive ACA rate in normal gravidas was 2.70%. The incidence of intrauterine growth retardation (IUGR) was 15.28% in cases of positive ACA, whereas was 1.77% in cases of negative ACA. There were significant differences between two groups (P < 0.001). Among children born in mothers with positive ACA, there were 5 cases of positive ACA. Immunocomplex depositions (Immunoglobulins & Complements) were all found in placenta of IUGR. CONCLUSIONS: ACA could be one of causes of IUGR. Determination of serum ACA would offer a new clue to diagnosis and treatment of IUGR. 相似文献
6.
Changes of glucose tolerance after partial pancreatectomy were divided into three types depending on the extent of resection. When 88 per cent or more of the pancreas was resected, hyperglycemia developed immediately, and when 70 to 88 per cent of the pancreas was resected, diabetes occurred after six weeks or more, but diabetes did not develop at all when less than 70 per cent of the pancreas was removed. The secretion of glucagon was maintained well, but that of insulin was easily impaired after resection of 70 per cent or more of the entire pancreas. 相似文献
7.
BL Horta CG Victora AM Menezes R Halpern FC Barros 《Canadian Metallurgical Quarterly》1997,11(2):140-151
Penile erection is a complex neurovascular event that represents a balance between corporal smooth muscle relaxation and contraction. This balance is determined by the interaction between proerectile and antierectile neurotransmitters. It is believed that nitric oxide is the primary erectogenic neurotransmitter and that noradrenaline (norepinephrine) is the primary erectolytic neurotransmitter. There are a number of pharmacological approaches to the management of erectile dysfunction and manipulation of the neurotransmitter systems. These involve direct delivery of drugs into the erectile chambers (intracavernosal injection therapy), administration of medications into the urethra (transurethral delivery), application of medications to the skin (transdermal delivery) and it is hoped that oral agents will be available in the very near future. This article reviews the world literature on the medications that have been investigated to date and their delivery routes. 相似文献
8.
An epidemiologic case-control study to ascertain the determinants of low birthweight was carried out in Santiago, Chile, from January to December 1989. The cases were defined as livebirths < 2500 g. The controls were livebirths > or = 2500 g of birthweight. All cases and a random sample (1:1) of controls were selected among 8,254 singleton births occurring at the El Salvador Hospital in the Eastern area of Santiago. These deliveries represented 50% of institutional deliveries in the area. Home deliveries (2%) and private hospital deliveries were not included in the study. Information was obtained from hospital medical records by six trained medical students. Some information could not be obtained from the hospital medical records. Thus the second step in data collection was the tracking of all the selected subjects to their referring neighborhood health centers. For the analysis, the data were divided into 3 case (outcome) categories: 453 subjects were the total case group. From these, 153 were the IUGR case group and 300 were the LBW preterm case group. The general control group consisted of 605 normal birthweight infants. 565 were the IUGR control group and 40 were the preterm control group. A total of 25 risk factors showed a significant crude odds ratio for at least one of the groups. In the multivariate logistic regression analysis eight variables: No. of pregnancies, previous adverse outcomes, previous LBW, pregnancy maternal weight, No. of visits, month of first prenatal care visit, maternal smoking and intrahepatic cholestasis of pregnancy, were significantly associated with LBW after adjustment by confounding. Eight risk factors: IUGR in previous pregnancies, Previous adverse outcome, Maternal smoking, intrahepatic cholestasis, maternal pregnancy weight, maternal height, month first prenatal visit, No. of visit, were significant to IUGR. Only two variables: pregnancy weight, divorced mother, were significantly associated with low birth weight in the preterm group. The most relevant risk factors were included in stepwise logistic regression models carried out for the outcome LBW for the general group, term group and preterm group, in order to adjust by confounding. Adjusted odds ratios were then obtained. Prenatal care related factors and maternal adverse obstetric factors were at higher significance for LBW in the general and IUGR groups. Only nutritional factors were related to LBW in preterm group. Women who delivered a LBW or IUGR infant were more likely to have fewer pregnancies, a history of previous LBW, lower prepregnancy weight and lower gestational weight gain. ICP was associated with an elevated risk of LBW that was independent of gestational age. 相似文献
9.
H Odendall 《Canadian Metallurgical Quarterly》1976,48(2):187-190
Electron microscopy of the absorption surface of the jejunal epithelium of the howler monkey Alouatta caraya showed the presence of core filaments implanted at the level of the terminal web in the microvilli. These microvilli are 5 to 7 mum long and up to 5 mum thick, their extraordinary development is attributed to a conditioned adaptation of the species to its feeding habits and nature of absorption. 相似文献
10.
Hematopoiesis in the vertebrate is characterized by the induction of ventral mesoderm to form hematopoietic stem cells and the eventual differentiation of these progenitors to form the peripheral blood lineages. Several genes have been implicated in the differentiation and development of hematopoietic and vascular progenitor cells, yet our understanding of the discrete steps involved in the induction of these cells from the ventral mesoderm is still incomplete. One method of delineating these processes is based on the use of lower vertebrates. The zebrafish (Danio rerio) is an especially robust vertebrate system for both isolating and characterizing genes involved in these processes. Hematopoietic mutants have been generated with defects in many of the steps of both the primitive and definitive hematopoietic programs. Cloning of the genes that underlie these mutations should yield valuable details of hematopoiesis and may have therapeutic implications for bone marrow transplantation and stem cell gene therapy. 相似文献
11.
Assignment of HLA-B types can be hampered by ambiguous reactivity of the typing sera resulting in inaccurate HLA-B assignments. In this study, 19 Korean samples exhibiting ambiguous serologic reactivities were characterized by DNA sequencing. Alleles identified from 7 samples were previously undetected in this population (B*1517, B*4101, B*4701, B*5001, and B*5106) and from 9 samples were common alleles in this population (B*4002, B*4003, B*4006, B*1501, B*1401, B*67012, and B*5401). Three samples were putative HLA-B homozygotes. Three major factors causing serologic ambiguity were identified: weak or false negative reactivity of typing sera (52.4%); cross or false positive reactivity of the sera (38.1%); and absence of information on the reaction patterns due to the lack of appropriate sera in the typing kit (e.g. B*4101 encoded molecule) or to the presence of recently characterized molecules (e.g. B*5106 encoded molecule) (9.5%). Overall, sequencing was helpful in clarifying ambiguous serologic reaction patterns improving the HLA typing for the Korean population. 相似文献
12.
A serie of radioprotective aminothiols was checked upon irradiation of the mice's brain. Cysteamine protects efficiently the brain as soon as 15 minutes after its administration. Among the tested aminothiols, it was the most effective compound. 2-isopropyl 1,3-thiazolane, rapidly hydrolysed, delivers a large amount of cysteamine in the brain and was nearly as potent as exogenous cysteamine. The other thiazolanes which delivered only progressively cysteamine or 2-mercaptopropylamine during a long period of time showed lesser efficacy. WR 2721 which did not penetrate the brain exhibited only a feeble radioprotection. The imperviousness to straight active aminothiols may be compensated by the diffusion of their precursors across the blood brain barrier and by their speed of hydrolysis, yielding active aminothiols during a short period of time between their administration and the irradiation. 相似文献
13.
In this study we show how the use of exon-primed, intron-crossing (EPIC) polymerase chain reaction (PCR) of a diploid intronic region, in conjunction with temperature gradient gel electrophoresis (TGGE), can be used to detect and rapidly assess allelic variation at the nucleotide level. We developed passerine-specific primers to amplify and sequence a 762 bp region including the second intron of the myoglobin gene in the Gouldian Finch, Erythrura gouldiae. A POLAND plot based on this sequence indicated that TGGE in combination with heteroduplex analysis (TGGE/HA) should reveal nucleotide variation in the 160 bp low-melting domain. Sequencing of the entire fragment from 19 Er. gouldiae revealed five nucleotide substitution differences within the low-melt domain, all of which could be detected and differentiated by TGGE/HA, and an additional substitution in a section of the high-melt domain which characterised another allele. A total of 181 individuals from four populations were screened for these six alleles. 相似文献
14.
We examined whether insulin-like growth factor-I (IGF-I) and one of its binding proteins (IGFBP-1) in fetal serum obtained by cordocentesis is correlated with intrauterine growth retardation (IUGR) and weight estimation by ultrasound. Cordocentesis sera from 27 fetuses suspected of having IUGR were analysed for IGF-I and IGFBP-1 by radioimmunoassay. The results showed that IGF-I concentrations were correlated significantly with birth weight (P < 0.001) and placenta weight (P < 0.05). Mean fetal concentrations of IGF-I were 38 +/- 18 microg/l. In patients (n = 11) with a weight deviation at delivery <-33%, IGF-I concentrations were 24.1 +/- 13.2 microg/l. IGFBP-1 was inversely correlated with birth weight (P < 0.006) and concentrations of IGF-I. Mean plasma concentrations of IGFBP-1 were 234.2 +/- 161.4 microg/l. Furthermore, IGF-I concentrations were correlated with the weight deviation estimated by ultrasonography at the time of cordocentesis (P < 0.007), as well as with the weight deviation at delivery (P < 0.0001). The actual weight deviation at delivery was correlated more strongly with fetal IGF-I concentrations than with the estimated weight deviation at cordocentesis. The lowest concentrations of IGF-I were found in patients with a weight deviation <-33%. Very low concentrations of IGF-I are thus associated with IUGR, indicating that IGF-I measured in fetal serum may increase the predictive value of ultrasonographic weight estimation. 相似文献
15.
16.
WP Frisbie M Biegler P de Turk D Forbes SG Pullum 《Canadian Metallurgical Quarterly》1997,87(12):1977-1983
OBJECTIVES: This study examined the extent of variation by race/ethnicity in the prevalence of adverse birth outcomes, whether differentials persisted after other risk factors were controlled for, and whether the direction and magnitude of relationships differed by type of outcome. METHODS: A revised system of measurement was used to estimate multinomial logistic models in a large, nationally representative US data set. RESULTS: Considerable racial/ethnic variation was found across birth outcome categories; differences persisted in the adjusted parameter estimates; and the effects of other risk factors on birth outcomes were similar as to direction, but varied somewhat in magnitude. The odds of compromised birth outcomes were much higher among African Americans than among Mexican Americans and non-Hispanic Whites. CONCLUSIONS: In addition to persistent racial inequality, we found strong adverse effects of both inadequate and "adequate-plus" prenatal care and smoking. Risk of intrauterine growth retardation was higher in the absence of medical insurance, and risk of all adverse birth outcomes was lower among mothers participating in the Special Supplemental Food Program for Women, Infants, and Children. 相似文献
17.
Risk factors for Aboriginal low birthweight (< 2500 g), preterm birth (< 37 weeks' gestation) and intrauterine growth retardation (under the tenth percentile of Australian birthweights for gestational age) were examined in 503 live-born singletons recorded as born to an Aboriginal mother and routinely delivered at the Royal Darwin Hospital between January 1987 and March 1990. Infants born to mothers with body mass index less than 18.5 kg/m2 had five times the risk of having low birthweight and 2.5 times the risk of intrauterine growth retardation. Population-attributable risk percentages suggest that 28 per cent of low birthweight and 15 per cent of growth retardation could be attributed to maternal malnutrition. Risk percentages for maternal smoking of more than half a packet of cigarettes a day were 18 per cent for low birthweight and 10 per cent for growth retardation. For growth retardation, 18 per cent could be attributed to a maternal age under 20 years. Risk factors for preterm birth were predominantly obstetric: the population-attributable risk percentage for pregnancy-induced hypertension was 26 per cent and for other obstetric conditions was 16 per cent. For Aboriginal births in the Darwin Health Region, maternal malnutrition and smoking are key elements in the prevention of low birthweight and intrauterine growth retardation. Teenage pregnancy is an important risk for intrauterine growth retardation, and pregnancy-induced hypertension is a risk for preterm birth. 相似文献
18.
SM Muaku JP Thissen G Gerard JM Ketelslegers D Maiter 《Canadian Metallurgical Quarterly》1997,42(3):370-377
In an earlier study, we found that yellow-rumped warblers had in vitro active uptake rates of D-glucose that were only a few percent of the glucose absorption rate achieved at the whole-animal level. Here we used a pharmacokinetic technique to test whether a substantial amount of sugar can be absorbed passively. We used yellow-rumped warblers (Dendroica coronata), known for their seasonal frugivory, freely feeding on a synthetic mash formulated with naturally occurring concentrations of D-glucose. Birds absorbed 89.8% +/- 1.0% (SE) of the D-glucose in the mash. When fed the same mash with trace-labeled 3H L-glucose, the stereoisomer that does not interact with the intestinal Na(+)-glucose cotransporter, 3H appeared in plasma, an indication that this stereoisomer of glucose was absorbed. We used 3H levels in plasma and excreta in a pharmacokinetic model to calculate L-glucose extraction efficiency (i.e., the percent absorbed). Calculated mean extraction efficiency for the passively absorbed L-glucose averaged 91% +/- 23%. Our finding of considerable passive absorption reconciles the in vitro and in vivo results for D-glucose absorption and is in concert with results from five other avian species. The passive pathway appears to provide birds with an absorptive process that can respond quickly to changing luminal concentration and that is energetically inexpensive to maintain and modulate in real time but that may bear a cost. Less discriminate passive absorption might increase vulnerability to toxins and thus constrain foraging behavior and limit the breadth of the dietary niche. 相似文献
19.
During the first week of life, we examined the changes in the systemic, intestinal and cerebral circulation, and the circulatory responses to feeding in 10 small for gestational age (SGA) infants using the ultrasound Doppler technique. From day 1 to day 3, preprandial cardiac output decreased (p < 0.01), whereas mean blood pressure (p < 0.01), superior mesenteric artery mean flow velocity (Vmean; p < 0.01) and middle cerebral artery Vmean (p < 0.01) increased. On day 1, cardiac output was higher in the SGA than in those of term and preterm appropriate for gestational age infants reported from our laboratory. Preprandial superior mesenteric artery Vmean was inversely related to the degree of growth retardation (r = 0.63, p < 0.05). However, growth retardation did not influence the postprandial increase in superior mesenteric artery Vmean and end-diastolic flow velocity, or the cerebral circulation. 相似文献
20.
This study examines the effect of maternally injected glucocorticoid on the pattern of hypoglycemia exhibited by rat pups with intrauterine growth retardation (IUGR). The majority of surgical procedures designed to produce small-for-gestational age (SGA) newborns for biochemical studies were carried out on days 18 and 19 of gestation because of favorable vields of pups with IUGR at those operative days. At birth, normal controls showed a mean +/- SE plasma glucose value of 63 +/- 2 mg/dl; mean glucose for the group with IUGR was significantly lower at 43 +/- 2 mg/dl. There was a further decrease in the plasma glucose concentration of pups with IUGR at 2-4 hr of age, whereas values in the control littermates did not fall during this interval. Through the first 2 hr of neonatal life, 46% of the pups with IUGR exhibited plasma glucose values less than 40 mg/dl, whereas only 18% of the control littermates manifiested hypoglycemia. During the 2-4-hr interval, the incidence of hypoglycemia in animals with IUGR increased to 91%; however, the incidence in control remained at 18% from 2-4 hr and fell to 4% at 4-6 hr of age. At birth, the pups with IUGR had a lower mean liver weight compared to their control littermates, but glycogen concentration of liver was similar to the control mean +/- SE of 25.7 +/- 1.8 (IUGR = 22.2 +/- 1.3 mg/g wet weight). Total hepatic glycogen stores, however, were markedly lower in dysmature rat pups (IUGR = 2.96 +/- 0.17 mg; control = 7.23 +/- 0.43 mg). Concentrations of plasma glucose at birth of individual control and IUGR animals were found to correlate significantly (r = 0.64, p less than 0.001) with total liver glycogen content. The decline in plasma glucose values in pups with IUGR was not present in animals whose dams received glucocorticoid injection 24 and 48 hr before delivery. At 4-6 hr of age, for instance, the mean plasma glucose concentration in the corticoid-treated IUGR group (70.1 +/- 6.9 mg/dl) approximated that of the control group. Instead on the 91% incidence of hypoglycemia noted in the nontreated dysmature pups, an incidence of 55% was found at 2-4 hr of age in offspring of mothers given glucocorticoid. At 4-6 hr, the treated group showed an incidence of 18% compared to a 67% figure in the nontreated IUGR animals. The concentration of liver glycogen in these animals also differed in that the treated IUGR pups showed significantly higher values (26.9 +/- 1.7 mg/g wet weight, mean +/- SE) than nontreated progeny. It is concluded that antenatally administered corticosteroid influence the development of neonatal hypoglycemia in the dysmature rat pup and that the major effect is not at birth, but during the 2-4-hr period of neonatal life. 相似文献