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OBJECTIVE: Because the survival rate has increased for extremely low birth weight neonates, many have raised the concern that the rate of developmental disability among survivors will also increase. To address this concern, we analyzed changes over time in survival and major neurosensory impairment in a sample of extremely low birth weight infants born between July 1, 1979, and June 30, 1994. METHODS: The study sample included 513 infants with birth weights of 501 to 800 g who were cared for in either of the two neonatal intensive care units that serve a 17-county region in northwest North Carolina and who were born to mothers residing in that region. At 1 year of age (corrected for gestation), survivors were examined by a pediatrician and were tested using the Bayley Scales of Infant Development. Major neurosensory impairment was defined as cerebral palsy, a Bayley Mental Developmental Index <68, or blindness. A total of 209/216 (97%) of survivors were examined at 1 year of age. Epoch of birth was defined as follows: epoch 1, July 1, 1979 to June 30, 1984; epoch 2, July 1, 1984 to June 30, 1989; and epoch 3, July 1, 1989 to June 30, 1994. RESULTS: Survival rates for epochs 1, 2, and 3 were, respectively, 24/120 (20%), 63/175 (36%), and 129/218 (59%). In contrast, the proportions with a major neurosensory impairment did not increase over time; rates for successive epochs were 6/24 (25%), 17/61 (28%), and 26/124 (21%). Rates of cerebral palsy were 3/24 (13%), 12/61 (20%), and 9/124 (7%); rates of delayed mental development were 4/24 (17%), 12/61 (20%), and 17/124 (14%); and rates of blindness were 2/24 (8%), 0/62, and 5/124 (4%), respectively. CONCLUSIONS: This analysis suggests that the increasing survival of extremely low birth weight neonates since the late 1970s has not resulted in an increased rate of major developmental problems identifiable at 1 year of age.  相似文献   
23.
In mandibular surgery, three-dimensionally printed patient-specific cutting guides are used to translate the preoperative virtually planned resection planes to the operating room. This study was performed to determine whether cutting guides are positioned according to the virtual plan and to compare the intraoperative position of the cutting guide with the resection performed. Nine patients were included. The exact positions of the resection planes were planned virtually and a patient-specific cutting guide was designed and printed. After surgical placement of the cutting guide, intraoperative cone beam computed tomography (CBCT) was performed. Postoperative CT was used to obtain the final resection planes. Distances and yaw and pitch angles between the preoperative, intraoperative, and postoperative resection planes were calculated. Cutting guides were positioned on the mandible with millimetre accuracy. Anterior osteotomies were performed more accurately than posterior osteotomies (intraoperatively positioned and final resection planes differed by 1.2 ± 1.0 mm, 4.9 ± 6.6°, and 1.8 ± 1.5°, respectively, and by 2.2 ± 0.9 mm, 9.3 ± 9°, and 8.3 ± 6.5° respectively). Differences between intraoperatively planned and final resection planes imply a directional freedom of the saw through the saw slots. Since cutting guides are positioned with millimetre accuracy compared to the virtual plan, the design of the saw slots in the cutting guides needs improvement to allow more accurate resections.  相似文献   
24.
ABSTRACT: BACKGROUND: Partner notification (PN) among individuals newly diagnosed with HIV/STI is seen as a vital tool to identify others at risk of infection. However, hardly any data are available on the effectiveness of PN on HIV/STI transmission in the Netherlands. This study aims to fill this gap by assessing current PN practices, case-finding effectiveness, and determinants of being notified among men having sex with men (MSM) in the Netherlands. METHODS: Nurses from five STI centers participated in a prospective pilot study on PN outcomes (partners being: at risk, notifiable, notified, and tested) for HIV/STI, by completing a newly developed PN registration form (PN database). PN outcomes including case-finding effectiveness (number of newly diagnosed cases in partners/number of partners being tested) for HIV, syphilis, and gonorrhoea were studied among MSM. Furthermore, the national STI database was analyzed to identify determinants of being notified. The number of infections that remained undetected was estimated based on these two databases. RESULTS: In total 105 MSM, newly diagnosed with HIV/STI, reported 612 sexual partners at risk of whom 41% were notifiable and 31% were notified. Patient referral was the predominant PN method (90%). The overall case-finding percentage was 36% (HIV: 15-33%, gonorrhoea: 17- 50% and syphilis: 4-11%). Case-finding percentages were lower in the national STI database: 21% (5%, 28%, 12%). Persons with one or more sexual partners, known HIV positives, and IDU were more likely to be notified to the STI clinic. Notified clients were more likely to have HIV/STI than unnotified clients (OR 1.7-2.5). Based on these two databases, an estimated 75 to 133 infections remained undetected (HIV: 12-90; gonorrhoea: 28-97; syphilis: 5-12 infections). CONCLUSIONS: Partner notification among MSM in the Netherlands is suboptimal; an extensive number of STI/HIV infections remained undetected mainly due to unnotifiable partners. To enhance PN practices, combined and innovative PN interventions such as Internet-based PN will be implemented for hard-to-reach MSM and other risk groups.  相似文献   
25.
Premature atherosclerosis is a clinical feature in adult-onset GH deficiency. Evidence is accumulating that disturbances in triglyceride metabolism, reflected by abnormalities in circulating remnant lipoproteins, are associated with increased atherogenic potential. In a case-controlled intervention study, we investigated postprandial lipoprotein metabolism using a new remnant lipoprotein method based on immunoseparation principle [RLP-cholesterol (RLP-C)]. In addition, we analyzed retinyl ester (RE) analysis in plasma and in Sf < 1000 fraction. Endothelial function was assessed as flow-mediated dilatation (FMD). Eight patients diagnosed with acquired adult-onset GH deficiency and eight controls matched for gender, age, body mass index, and apolipoprotein (apo) E genotype were enrolled in the study. Oral vitamin A fat loading tests were performed at baseline in both groups and after 6 months of treatment with recombinant human GH (rh-GH) in the adult-onset GH-deficient patients. Adult-onset GH-deficient patients had significantly higher fasting RLP-C, postprandial RLP-C concentrations (plasma RLP-C, 0.29 +/- 0.14 mmol/L; and incremental area under the curve-RLP-C, 2.13 +/- 1.60 mmol*h/L, respectively) than controls (0.19 +/- 0.06 mmol/L and 1.05 +/- 0.72 mmol*h/L (P: < 0.05), respectively). They also had significantly higher postprandial RE in plasma and Sf < 1000 fraction. Treatment with rh-GH significantly reduced postprandial RLP-C concentrations (incremental area under the curve-RPL-C 0.73 +/- 0.34 mmol*h/L; P: < 0.05) but had no effects on the fasting RLP-C concentrations (0.317 +/- 0.09 mmol/L, P: < 0.05), or on the postprandial RE in plasma and in Sf < 1000 fraction. Endothelial function measured as FMD was improved from 5.9 +/- 3.3% to 10.2 +/- 4.0% (P: < 0.05) in patients treated with rh-GH. It is concluded that patients with adult-onset GH deficiency have increased levels of fasting and postprandial RLP-C and an impaired endothelial function as measured as FMD. Treatment with rh-GH resulted in a decrease of postprandial RLP-C concentration, thereby improving the postprandial atherogenic lipoprotein profile and improvement of endothelial function, however, the clearance of large chylomicron particles as reflected by RE remained disturbed.  相似文献   
26.
Familial hypercholesterolemia (FH) and disturbances in postprandial lipoprotein metabolism are both associated with premature atherosclerosis. The effect of beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitors on plasma cholesterol levels in patients with FH is well established; however, it is not known whether postprandial lipoproteins are also influenced. In this case-controlled intervention study, we investigated the effects of high-dose simvastatin on postprandial lipoproteins. We used a new method to analyze remnant lipoproteins based on the immunoseparation principle (remnant-like particle cholesterol [RLP-C] assay) and the well-established measurement of retinyl ester (RE) analysis in plasma and in the Svedberg flotation unit (Sf)<1000 fraction. Seven heterozygous FH patients and 7 control subjects matched for sex, age, body mass index, triglycerides, and apolipoprotein E genotype were enrolled in the study. An oral vitamin A (RE) fat-loading test was performed at baseline in both groups and after 3 months of high-dose simvastatin (80 mg/d) treatment in the FH patients. Before treatment, FH patients had significantly higher fasting and postprandial concentrations of lipoprotein remnants (plasma RLP-C 42+/-19 mg/dL and area under the RLP-C curve 415+/-82 mg. L(-1). h(-1), respectively) than did control subjects (7+/-3 mg/dL and 101+/-35 mg. L( -1). h(-1), respectively; P<0.05), suggesting a delayed clearance of chylomicron remnant particles in the FH patients. Treatment with simvastatin significantly reduced fasting and postprandial remnant lipoprotein cholesterol concentrations (13+/-3 mg/dL and 136+/-53 mg. L(-1). h(-1), respectively; P<0.05 for both). Postprandial RE in the Sf<1000 fraction, not total RE in plasma, was also significantly higher in FH patients than in control subjects (24+/-10 versus 6.3+/-5.9 mg. L( -1). h(-1), P<0.05), but treatment with simvastatin did not result in improvement of the postprandial RE response, either in the Sf<1000 fraction or in plasma. It is concluded that heterozygous FH patients have increased fasting and postprandial remnant lipoprotein concentrations. Treatment with simvastatin significantly reduced the fasting and postprandial RLP-C concentrations but did not result in improved postprandial RE response.  相似文献   
27.
Sixty-five multiply transfused patients with severe aplastic anemia were given cyclophosphamide followed by grafts anemia were given cyclophosphamide followed by grafts from HLA-identical siblings. The effect of the administration of viable donor buffy coat cells following the marrow inoculum was evaluated with regard to graft rejection and survival. Results in 43 patients so treated are presented along with those in 22 concurrent patients given marrow alone. Most patients given buffy coat had positive in vitro tests of sensitization indicating a high risk for graft rejection, while all but one of the patients given marrow alone had negative tests. Thirty of the 43 (70%) patients given marrow and buffy coat are alive between 10 and 61 mo (median 36) after grafting; 4 died after graft rejection and 6 with acute or chronic graft-versus-host disease (GVHD). Eleven of the 22 (50%) patients given marrow alone are alive between 29 and 65 mo (median 52); 7 died after graft rejection and 3 with GVHD. The addition of buffy coat cell infusions to the marrow inoculum reduced the risk of rejection and increased survival in the currently reported transfused patients when compared to patients grafted before 1976. However, there was an increased risk of chronic GVHD. Recipients of marrow from female donors survived slightly better (73%) than recipients of male marrow (58%).  相似文献   
28.
Haematoxenus veliferus was experimentally transmitted in cattle on two occasions by the tick Amblyomma variegatum; transmission was transstadial, from nymph to adult. Theileria mutans and Cowdria ruminatium were transmitted at the same time. H. veliferus infected at least 15% of red cells in a splenectomized steer and 10% in a normal steer. One experiment on transstadial transmission from larva to nymph was unsuccessful.  相似文献   
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The course after hepatitis B virus infection seems to be determined by the host's immune response, which in turn may be regulated by the major histocompatibility complex. In order to find a possible relationship between the course of disease and the phenotype frequency of HLA determinants, we studied 396 Dutch subjects of northern European local race. Six groups of individuals with various courses after hepatitis B virus infection were compared to healthy controls. The hepatitis B patients were grouped according to standard criteria: 47 had recovered from acute symptomatic hepatitis B virus infection; 60 had recovered from asymptomatic hepatitis B virus infection; 26 were asymptomatic hepatitis B surface antigen carriers; 16 had chronic persistent hepatitis B; 37 had chronic active hepatitis B, and 10 had chronic active hepatitis after elimination of hepatitis B antigens. Twenty-nine Class I and 13 Class II HLA antigens were assayed by standard microlymphocytotoxicity tests. The phenotype frequency of the Class II antigen DQw1 appeared to be significantly lower in patients with chronic active hepatitis B virus infection. Some other HLA specificities showed deviations from control values, but they were not statistically significant after correction for the number of antigens tested. In conclusion, we have found no evidence that the elimination of hepatitis B virus is related to HLA phenotype. DQw1, however, may affect the morphologic type of chronic hepatitis B infection, since its presence may protect against chronic active hepatitis.  相似文献   
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