Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 125
Filtrar
1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(5): 891-895, 2021 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-34650290

RESUMO

OBJECTIVE: To bring forward an arthroscopic classification of the popliteal hiatus of the lateral meniscus (PHLM) tears and to assess the effects of arthroscopic all-inside repair with suture hook in management of such injuries. METHODS: This study involved 146 patients who underwent arthroscopic operation because of PHLM tears from April 2014 to October 2017, eliminating the patients who had discoid lateral meniscus. There were 81 males and 65 females, with 54 left knees and 92 right knees. The average ages were (34.7±3.7) years. Among the selected participants, there were 107 patients with anterior cruciate ligament (ACL) injuries, 39 patients with medial collateral ligament (MCL) injuries, and 48 patients with medial meniscus tears. The average preoperative Lysholm and International Knee Documentation Committee (IKDC) scores were 57.7±9.2 and 54.1±8.9, respectively. The arthroscopic classification was based on the extent and degree of PHLM tears and using the arthroscopic all-inside repair with suture hook for such injuries. For the patients associated with ACL injuries, the ipsilateral autograft hamstring tendons use as the reconstruction graft for single bundle ACL reconstructions. The suture anchors were used for treatment of MCL Ⅲ injuries, and the arthroscopic all-inside repair for medial meniscus tears. RESULTS: A total of 146 PHLM tears in 146 patients were divided into type Ⅰ (tears not involved in popliteus tendon incisura; n=86, 58.9%), type Ⅱ (tears involved in popliteomeniscal fascicles; n=36, 24.7%), and type Ⅲ (tears involved in popliteus tendon incisura; n=24, 16.4%). For type Ⅰ, there were three subtypes, including type Ⅰa: longitudinal tear (n=53, 61.6%), type Ⅰb: horizontal tear (n=27, 31.4%), and type Ⅰc: radial tear (n=6, 7.0%). For type Ⅱ, there were also three subtypes, including type Ⅱa: anterosuperior popliteomeniscal fascicle tear (n=5, 13.9%), type Ⅱb: posterosuperior popliteomeniscal fascicle tear (n=20, 55.6%), and type Ⅱc: both tears (n=11, 30.6%). For type Ⅲ, there were two subtypes, including type Ⅲa: horizontal tear (n=9, 37.5%), type Ⅲb: radial tear (n=15, 62.5%). In the follow-up for an average of 15.3±2.6 months, all the patients had done well with significantly improved Lysholm (84.6±14.3) and IKDC (83.2±12.8) scores at the end of the last follow-up relative to preoperative scores (P > 0.01). CONCLUSION: We propose that it is possible to classify lateral meniscus tears at the popliteal hiatus region for three types, which can summarize the injury characteristics of this area. The arthroscopic all-inside repair with suture hook for the PHLM tears can avoid stitching to popliteal tendon or narrowing popliteal hiatus and have satisfactory clinical results.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Lesões do Menisco Tibial , Adulto , Lesões do Ligamento Cruzado Anterior/cirurgia , Artroscopia , Feminino , Humanos , Masculino , Meniscos Tibiais/cirurgia , Lesões do Menisco Tibial/cirurgia
2.
Adv Funct Mater ; 31(6)2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33708036

RESUMO

Itaconate (ITA) is an emerging powerhouse of innate immunity with therapeutic potential that is limited in its ability to be administered in a soluble form. We developed a library of polyester materials that incorporate ITA into polymer backbones resulting in materials with inherent immunoregulatory behavior. Harnessing hydrolytic degradation release from polyester backbones, ITA polymers resulted in the mechanism specific immunoregulatory properties on macrophage polarization in vitro. In a functional assay, the polymer-released ITA inhibited bacterial growth on acetate. Translation to an in vivo model of biomaterial associated inflammation, intraperitoneal injection of ITA polymers demonstrated a rapid resolution of inflammation in comparison to a control polymer silicone, demonstrating the value of sustained biomimetic presentation of ITA.

3.
Environ Technol ; 41(22): 2955-2969, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30907240

RESUMO

Nоblе mеtаls suppоrtеd оn TiО2 (Dеgussа P25) mоdifiеd with WО3 undеr thе еffесt оf fееding оxуgеn аnd оzоnе соntаining mixturе tо thе rеасtоr undеr UV-С irrаdiаtiоn wеrе еxаminеd fоr thеir саtаlуtiс асtivitу in thеrеасtiоn оf оxаliс асid liquid phаsе оxidаtiоn. Thе sаmplеs wеrе sуnthеsizеd bу еxtrасtivе-pуrоlуtiс mеthоd bу lоаding 4 wt.% WО3 аnd 1 wt.% оf thе асtivе mеtаl hаving pаrtiсlеs sizе vаrуing frоm 5 tо 30 nm. Thе XPS, XRD, TЕM аnd BЕT mеthоds wеrе еmplоуеd fоr thеir struсturаl аnd сhеmiсаl сhаrасtеrizаtiоn. In thе prеsеnсе оf оxуgеn undеr UV light thе limiting stеp zеrо-оrdеr rеасtiоn rаtе оf TiО2/WО3/Pt sаmplе wаs highеst аmоng thе tеstеd саtаlуsts аnd it wаs 2.3 timеs highеr thаn thаt оf thе purе TiО2 undеr thе sаmе соnditiоns. Thе inсrеаsеd асtivitу оf thе соmpоsitе саtаlуsts wаs duе tо thе mоrе еffiсiеnt sеpаrаtiоn оf thе еlесtrоn-hоlе сhаrgе саrriеrs gеnеrаtеd during irrаdiаtiоn, whiсh wаs соmbinаtiоn frоm thе bеnеfiсiаl еffесt оf thе WО3 аnd nоblе mеtаl. Furthеr, thе еffесtivеnеss оf thе саtаlуsts in rеgаrd tо thе phоtооxidаtiоn оf оxаliс асid in thе prеsеnсе оf оzоnе is grеаtеr bеtwееn 4-5 timеs fоr аll tеstеd sаmplеs. Thе highеst асtivitу undеr fееding оf оzоnе wаs shоwn bу TiО2/WО3/Pd thаt wаs аsсribеd tо thе highеst оzоnе dесоmpоsitiоn аbilitу оf thе pаllаdium suppоrtеd оn TiО2 rеsulting in асtivе оxуgеn аtоms fоrmаtiоn thаt fасilitаtе thе dеgrаdаtiоn оf оxаliс асid.


Assuntos
Oxalidaceae , Ozônio , Metais , Fotólise , Titânio , Raios Ultravioleta
4.
Nat Commun ; 9(1): 2003, 2018 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-29784909

RESUMO

Two-dimensional (2D) topological insulators (TIs) are promising platforms for low-dissipation spintronic devices based on the quantum-spin-Hall (QSH) effect, but experimental realization of such systems with a large band gap suitable for room-temperature applications has proven difficult. Here, we report the successful growth on bilayer graphene of a quasi-freestanding WSe2 single layer with the 1T' structure that does not exist in the bulk form of WSe2. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we observe a gap of 129 meV in the 1T' layer and an in-gap edge state located near the layer boundary. The system's 2D TI characters are confirmed by first-principles calculations. The observed gap diminishes with doping by Rb adsorption, ultimately leading to an insulator-semimetal transition. The discovery of this large-gap 2D TI with a tunable band gap opens up opportunities for developing advanced nanoscale systems and quantum devices.

5.
Zhonghua Yan Ke Za Zhi ; 53(5): 332-337, 2017 May 11.
Artigo em Chinês | MEDLINE | ID: mdl-28494560

RESUMO

Objective: To investigate the visual impact and influence factors of sub-Tenon's anesthesia in retinal detachment patients during pars plana vitrectomy (PPV) or combined phacoemulsification and PPV surgery. Methods: In this prospective case series study, 104 consecutive patients who underwent PPV or combined phacoemulsification and PPV under sub-Tenon's anesthesia between October 2012 and December 2013 were enrolled. Intraoperatively, the patients were asked whether they could see the light of the operating microscope or not at 5 minutes after sub-Tenon's anesthesia, and at the end of phacoemulsification, core vitreous removal, peripheral vitreous removal and the whole surgery, with their contralateral eyes being covered tightly and no photobleaching. The best corrected visual acuity and visual evoked potentials were examined and compared with each other preoperatively and at 1.5 months and 3 months postoperatively. Chi-square test was used to compare the detection rate of amaurosis between different modus operandi and whether covered contra-lateral eye. Student-t test was used to compare the difference of age and preoperative BCVA between the patients with or without experienced amaurois. Lastly, BCVA between different times were tested by one-way ANOVA analysis. Results: Without covering the contralateral eyes, the incidence of no light perception in various surgical steps was 0%, while it was 72.1%(75/104), 93.8%(75/80), 96.2%(100/104), 96.2%(100/104) and 86.5%(90/104) at the five timepoints, respectively, when the contralateral eyes were covered tightly. The incidence was 51.9%(54/104), 85.0%(68/80), 85. 6%(89/104), 84.6%(69/104) and 66.3%(88/104), respectively, after photobleaching was excluded. Approximately 95.2%(99/104) of patients reported no light perception at least once, 54.5%(54/99) reported no light perception 5 minutes after sub-Tenon's anesthesia, and 30.3%(30/99) recovered light perception when the surgery was finished. All eyes recovered to at least light perception on the first postoperative day. The best corrected visual acuity and visual evoked potentials at 1.5 months and 3 months postoperatively were significantly better than those before surgery. The BCVA was 1.75±0.78 preoperative, 0.96±0.63 1.5 months after operation, and 0.92±0.57 3 months after operation. There was a significant statistical difference between preoperative BCVA and postoperative BCVA (F=50.61, P<0.01) . In patients without waveform detection preoperatively, PVEP waveform could be found in 43.6% and 61.4% of the pactients at 1.5 months and 3 months after operation respectively. In those had certain waveform preoperatively, PVEP amplitudes rise significantly after surgery (t(1.5)=-2.69, t(3)=-2.97, P<0.05) . Conclusions: No light perception was detected in various surgical steps of vitrectomy under sub-Tenon's anesthesia in most patients. The blocking of optic nerve conduction may be caused by sub-Tenon' s anesthesia. Photobleaching can also have some effect. The incidence of no light perception during the surgery was not correlated with preoperative visual acuity, age and gender. Moreover, the effect was transient and harmless to visual function.(Chin J Ophthalmol, 2017, 53: 332-337).


Assuntos
Amaurose Fugaz/diagnóstico , Anestesia Local/métodos , Facoemulsificação , Complicações Pós-Operatórias/diagnóstico , Descolamento Retiniano/cirurgia , Vitrectomia , Idoso , Amaurose Fugaz/epidemiologia , Distribuição de Qui-Quadrado , Terapia Combinada/métodos , Potenciais Evocados Visuais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Acuidade Visual
6.
Zhonghua Shao Shang Za Zhi ; 33(4): 228-232, 2017 Apr 20.
Artigo em Chinês | MEDLINE | ID: mdl-28427136

RESUMO

Objective: To investigate the effects and related mechanism of bivalirudin on the survival of random skin flap on the back of rat. Methods: Thirty SD rats were divided into bivalirudin group and normal saline group according to the random number table, with 15 rats in each group. The random flap model with size of 9 cm×3 cm was reproduced on the back of rats in two groups. Immediately post injury, rats in bivalirudin group were intraperitoneally injected with 5 mg/mL bivalirudin (0.8 mL/kg), while rats in normal saline group were intraperitoneally injected with normal saline (0.8 mL/kg) once a day. The continuous injection lasted for 7 days. The flap was divided into distal area, middle area and proximal area averagely based on the flap blood supply. On post injury day (PID) 1, 3, and 7, the overall survival of each area of flap was observed with naked eyes. On PID 7, the survival rate of flap was calculated, and then the morphology of skin tissue at the center of the three areas of flap was observed by HE staining, the microvessel density (MVD) of the middle area of flap was calculated, and the expression of vascular endothelial growth factor (VEGF) of the middle area of flap was detected with immunohistochemical staining. Data were processed with t test. Results: (1) On PID 1, flaps of rats in two groups had different degrees of swelling, mainly concentrated in distal area, but there was no obvious necrosis. The middle area and proximal area of flaps in two groups were survived. On PID 3, the necrosis of flaps of rats in two groups was concentrated in the middle area, while the proximal area of flap was still in survival state, and most distal area of flap was necrosis with a little scab. On PID 7, the necrosis of middle area of flaps of rats in two groups was gradually fused, and the survival area of flap of rats in bivalirudin group was larger than that in normal saline group. The distal area of flap was almost necrotic, and the proximal area of flap was almost survived. (2) On PID 7, the survival rate of flap of rats in bivalirudin group was (64±4)%, significantly higher than that in normal saline group [(45±3)%, t=13.49, P<0.01]. (3) On PID 7, the histological morphology of distal area of flap of rats in two groups was similar, the inflammatory cells were infiltrated abundantly, and tissue edema was obvious. A large number of new blood vessels appeared in the middle area of flap of rats in bivalirudin group, with the formation of collateral vessels, and basic dilation of new blood vessels was seen. There were fewer new blood vessels appeared in the middle area of flap of rats in normal saline group, and dilation of new blood vessels was not obvious. There was little inflammatory cells infiltration in the proximal area of flap of rats in two groups. Compared with that in normal saline group, tissue edema extent of proximal area of flap of rats in bivalirudin group was less, and expansion was observed in more blood vessels. (4) The MVD of middle area of flap of rats in bivalirudin group was (26±5)/mm(2,) significantly higher than that in normal saline group [(18±3)/mm(2,) t=5.43, P<0.05]. (5) The expression of VEGF of middle area of flap of rats in bivalirudin group was 6 534±384, significantly higher than that in normal saline group (4 659±448, t=12.31, P<0.05). Conclusions: Bivalirudin can promote the survival of random skin flap in rats, and the mechanisms may include reducing the formation of thrombosis, improving the blood supply of flap, and increasing the expression of VEGF, promoting the formation of new blood vessels.


Assuntos
Antitrombinas/farmacologia , Sobrevivência de Enxerto , Hirudinas/farmacologia , Fragmentos de Peptídeos/farmacologia , Retalhos Cirúrgicos , Animais , Masculino , Necrose , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Pele , Taxa de Sobrevida , Fator A de Crescimento do Endotélio Vascular
7.
Genet Couns ; 23(1): 1-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22611635

RESUMO

We report an 82-year-old girl with premature aging, a karyotype of 46,XX and a de novo c.1824C>T mutation encoding p.G608G in the lamin A gene. The clinical features of accelerated aging and the molecular finding were consistent with the diagnosis of Hutchinson-Gilford progeria syndrome (HGPS). In this presentation, we demonstrate the radiological imaging findings of skeletal, oral and craniofacial phenotypes of abnormalities associated with HGPS. The oral and craniofacial abnormalities caused dental caries, severe malocclusion, and swallowing, feeding and speech problems. Dural calcification, and granulation in the ear drum and external ear canal were additionally observed.


Assuntos
Anormalidades Craniofaciais/diagnóstico por imagem , Cárie Dentária/diagnóstico por imagem , Fêmur/diagnóstico por imagem , Mãos/diagnóstico por imagem , Progéria/diagnóstico por imagem , Criança , Anormalidades Craniofaciais/genética , Cárie Dentária/genética , Feminino , Humanos , Lamina Tipo A/genética , Mutação , Progéria/genética , Radiografia
8.
Eur J Pediatr Surg ; 20(4): 257-61, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20486039

RESUMO

BACKGROUND: To develop a physeal slide-traction plate for children can provide rigid internal fixation of a bone fracture without inhibiting epiphyseal growth. METHODS: The slide-traction plates and standard plates were designed to configure to the femoral condyle. Twelve of thirty goats were used as normal controls and the rest were implanted with plates (right femurs were fixed with standard plates, and left femurs were fixed with slide-traction plates). All goats underwent X-ray examination at 1 month, 3 months and 6 months after surgery, and femoral length were measured. Histological staining and electron microscopy were performed to evaluate the development of the epiphyseal plate at 3 and 6 months after surgery. RESULTS: Compared to the standard plate, the slide-traction plate group exhibited more normal physeal growth, histologic features, safranin O staining, and electron microscopy structural features. There were significant differences in length in the femurs of goats fixed with slide-traction plates and standard plates at 1 month, 3 months, and 6 months after surgery, respectively. There was no difference between femurs of the normal control group and the femurs fixed with the slide-traction plates. Thicker epiphyseal plates were found in the left vs. the right femurs of the group fixed with plates at 3 and 6 months after surgery. In the group fixed with plates, Safranin O staining showed that the epiphyseal plates of the left femurs had more fuscous staining than the right femurs at 3 and 6 months after surgery. Electron microscopy also showed that cells in the epiphyseal plates of the left femurs were healthier in appearance than cells from the right femurs in the group fixed with plates. CONCLUSION: The physeal slide-traction plate can slide with the growth of the physis and is suitable for fixation of fractures in this region.


Assuntos
Placas Ósseas , Fraturas do Fêmur/cirurgia , Fêmur/crescimento & desenvolvimento , Fixação Interna de Fraturas/instrumentação , Animais , Modelos Animais de Doenças , Feminino , Fraturas do Fêmur/patologia , Seguimentos , Consolidação da Fratura , Cabras , Lâmina de Crescimento/crescimento & desenvolvimento , Lâmina de Crescimento/ultraestrutura , Masculino , Microscopia Eletrônica , Desenho de Prótese , Resultado do Tratamento
10.
Phys Rev Lett ; 94(19): 196103, 2005 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-16090191

RESUMO

Scanning tunneling microscopy is employed to investigate the recombinative desorption of H2 from hydrogenated Si(100) surfaces consisting of dihydride (SiH2) and monohydride (SiH) surface species organized in (1 x 1), (3 x 1), and (2 x 1) configurations. The results show that desorption from dihydrides involves a pair of neighboring dihydrides linked along the tetrahedral bond direction. Dihydrides in (3 x 1) domains are separated in the same direction by monohydrides, and desorption from a pair is geometrically impossible. The same desorption mechanism nevertheless applies via first a position switching of dihydrides with neighboring monohydrides.

11.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 3753-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-17271111

RESUMO

In the present study, lidocaine relaxed, in a concentration-dependent manner, the contractions induced by either phenylephrine or a high concentration of KCl (60 mM) in endothelium-intact rat aortic rings. Mechanical removal of endothelium did not significantly modify lidocaine-induced vasorelaxation. In endothelium-denuded aortic rings depolarized by 60 mM KCl, lidocaine inhibited Ca2+-induced contraction. Lidocaine also reduced the transient contraction elicited by phenylephrine in Ca2+-free medium. Pretreatment of endothelium-denuded aorta nonspecific K+ with tetraethylammonium, a channel blocker, had no effect on the relaxant effect of lidocaine. These results indicate that lidocaine induces an endothelium-independent relaxation in rat aortic rings. The main mechanisms may include suppression in Ca2+ through the voltage-sensitive Ca2+ influx intracellular Ca2+ channels and inhibition of release in the vascular smooth muscle cells.

12.
Phys Rev Lett ; 90(4): 046102, 2003 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-12570436

RESUMO

Chlorine termination of mixed Ge/Si(100) surfaces substantially enhances the contrast between Ge and Si sites in scanning tunneling microscopy observations. This finding enables a detailed investigation of the spatial distribution of Ge atoms deposited on Si(100) by atomic layer epitaxy. The results are corroborated by photoemission measurements aided by an unusually large chemical shift between Cl adsorbed on Si and Ge. Adsorbate-substrate atomic exchange during growth is shown to be important. The resulting interface is thus graded, but characterized by a very short length scale of about one monolayer.

13.
Am J Clin Nutr ; 74(1): 44-9, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451716

RESUMO

BACKGROUND: Sterols in feces reflect sterols in the diet. In previous analyses of the fecal steroids in 1000-2000-y-old Native American coprolites found in the dry caves of Nevada, we showed that the sterol nucleus was stable. The coprolites provided useful dietary information. OBJECTIVE: In the present study, we analyzed the fecal steroids of an Eskimo mummy buried and frozen >500 y ago in Greenland. We compared these analyses with our findings in the coprolites from Nevada and in present-day stool samples from Tarahumara Indians of Mexico and Americans consuming low- and high-cholesterol diets. DESIGN: The fecal material from the Eskimo mummy was subjected to saponification, extraction, and digitonin precipitation. The sterols and bile acids were further analyzed by thin-layer chromatography and gas-liquid chromatography. RESULTS: The fecal steroids of the Greenland Eskimo mummy were remarkably similar to those of present-day stool samples. However, unlike in the stool of modern humans, a portion of the neutral steroids in the coprolite had been converted to sterol epimers. Instead of deoxycholic acid, 3alpha,6beta,12alpha-trihydroxycholanic acid was one of the major fecal bile acids. The plant sterol output in the coprolite was only 0.4% of the output of Americans consuming 250-400 mg plant sterols/d. The ratio of bile acid to cholesterol in the coprolite was similar to that in stool from Tarahumara Indians consuming a low-cholesterol diet. CONCLUSION: The sterol nucleus is stable when frozen. The analysis of coprolite showed that the young Eskimo woman had consumed a diet very low in plant sterols and moderate to low in cholesterol content.


Assuntos
Dieta/história , Fezes/química , Inuíte/história , Múmias/história , Esteroides/análise , Ácidos e Sais Biliares/análise , Colestanol/análise , Colesterol/administração & dosagem , Colesterol/análise , Cromatografia Gasosa , Cromatografia em Camada Fina , Groenlândia , História do Século XV , Humanos , Indígenas Norte-Americanos , Nevada , Fitosteróis/administração & dosagem , Fitosteróis/análise
14.
J Lipid Res ; 41(9): 1437-47, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10974051

RESUMO

The Smith-Lemli-Opitz syndrome (SLOS) is a multiple malformation/mental retardation syndrome caused by a deficiency of the enzyme 7-dehydrocholesterol Delta(7)-reductase. This enzyme converts 7-dehydrocholesterol (7-DHC) to cholesterol in the last step in cholesterol biosynthesis. The pathology of this condition may result from two different factors: the deficiency of cholesterol itself and/or the accumulation of precursor sterols such as 7-DHC. Although cholesterol synthesis is defective in cultured SLOS cells, to date there has been no evidence of decreased whole body cholesterol synthesis in SLOS and only incomplete information on the synthesis of 7-DHC and bile acids. In this first report of the sterol balance in SLOS, we measured the synthesis of cholesterol, other sterols, and bile acids in eight SLOS subjects and six normal children. The diets were very low in cholesterol content and precisely controlled. Cholesterol synthesis in SLOS subjects was significantly reduced when compared with control subjects (8.6 vs. 19.6 mg/kg per day, respectively, P < 0.002). Cholesterol precursors 7-DHC, 8-DHC, and 19-nor-cholestatrienol were synthesized in SLOS subjects (7-DHC synthesis was 1.66 +/- 1.15 mg/kg per day), but not in control subjects. Total sterol synthesis was also reduced in SLOS subjects (12 vs. 20 mg/kg per day, P < 0.022). Bile acid synthesis in SLOS subjects (3.5 mg/kg per day) did not differ significantly from control subjects (4.6 mg/kg per day) and was within the range reported previously in normals. Normal primary and secondary bile acids were identified. This study provides direct evidence that whole body cholesterol synthesis is reduced in patients with SLOS and that the synthesis of 7-DHC and other cholesterol precursors is profoundly increased. It is also the first reported measure of daily bile acid synthesis in SLOS and provides evidence that bile acid supplementation is not likely to be necessary for treatment. These sterol balance studies provide basic information about the biochemical defect in SLOS and strengthen the rationale for the use of dietary cholesterol in its treatment.


Assuntos
Ácidos e Sais Biliares/metabolismo , Colesterol/metabolismo , Síndrome de Smith-Lemli-Opitz/metabolismo , Esteróis/sangue , Adolescente , Pré-Escolar , Colesterol na Dieta , Feminino , Humanos , Lactente , Masculino , Valores de Referência , Síndrome de Smith-Lemli-Opitz/sangue
15.
Am J Med Genet ; 93(5): 360-5, 2000 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-10951458

RESUMO

Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive condition comprising multiple malformations, mental retardation, and growth failure, results from reduced activity of the final enzyme in cholesterol biosynthesis, 7-dehydrocholesterol Delta(7)-reductase (DHCR7). Reduced plasma and tissue cholesterol concentrations and accumulation of cholesterol precursors including 7-dehydrocholesterol (7-DHC) are characteristic biochemical abnormalities. While it is still unclear what role these potentially toxic precursors have in the pathogenesis of this disorder, the accumulation of 7-DHC in the brain has been associated with impaired learning in rats and oxidized 7-DHC has been shown to induce growth retardation in cultured rat embryos. We hypothesized that supplemental dietary cholesterol would increase plasma cholesterol levels and suppress synthesis of 7-DHC and other abnormal sterols in individuals with SLOS. After baseline sterol levels were obtained, patients were provided supplemental cholesterol as egg yolk. Plasma sterols were analyzed by capillary-column gas chromatography over time in four children with SLOS. When evaluated at 4-8 weeks after the initiation of cholesterol supplementation, there was a marked increase in mean plasma cholesterol, from 53 mg/dl to 82 mg/dl. While the percent of total sterols as 7-DHC decreased from 15% to 10%, there was no change in total plasma 7-DHC levels. However, when evaluated 35-90 weeks after the institution of cholesterol supplementation, mean plasma 7-DHC decreased, from 11.3 mg/dl to 3.5 mg/dl (-67%, P < 0.05), along with an increase in mean plasma cholesterol from 53 mg/dl to 114 mg/dl (+116%, P < 0.05). These results support the hypothesis that over time dietary cholesterol supplementation from egg yolk increases the plasma cholesterol levels and decreases levels of 7-DHC which may be toxic. These data have important therapeutic implications in the management of SLOS.


Assuntos
Colesterol na Dieta/metabolismo , Colesterol/sangue , Desidrocolesteróis/sangue , Gema de Ovo/metabolismo , Síndrome de Smith-Lemli-Opitz/terapia , Colesterol na Dieta/administração & dosagem , Feminino , Humanos , Lactente , Masculino , Síndrome de Smith-Lemli-Opitz/sangue , Síndrome de Smith-Lemli-Opitz/metabolismo
16.
Pediatr Infect Dis J ; 19(3): 223-7, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10749464

RESUMO

OBJECTIVES: To compare the accuracy of standard and hemocytometer white blood cell (WBC) counts and urinalyses for predicting urinary tract infection (UTI) in febrile infants. METHODS: Enrolled were 230 febrile infants < 12 months of age. All urine specimens were obtained by suprapubic bladder aspiration and microscopically analyzed by the standard urinalysis (UA) and by hemocytometer WBC counts simultaneously, and quantitative urine cultures were performed. Receiver-operating characteristic (ROC) curves were constructed for each method of UA. The optimal cutoff point of the UA test in predicting UTI was determined by ROC analysis. RESULTS: There were 37 positive urine cultures of at least 1,000 CFU/ml. Of these 37 patients, 9 females and 28 males, 1 had a positive blood culture (Escherichia coli). Thirty (81%) of the positive urine cultures had a bacterial colony count > or = 100,000 colony-forming units/ml, whereas the remaining had between 1,000 and 50,000 colony-forming units/ml. The area under the ROC curve for standard UA was 0.790 +/- 0.053, compared with 0.900 +/- 0.039 for hemocytometer WBC counts (P < 0.05). For hemocytometer WBC counts, the presence of < or =10 WBC/microl appeared to be the most useful cutoff point, yielding a high sensitivity (83.8%) and specificity (89.6%). Standard UA, with a cutoff point of 5 WBC/high power field, had a lower sensitivity (64.9%) and similar specificity (88.1%). The hemocytometer WBC counts showed significantly greater sensitivity and positive predictive value (83.8 and 60.8%, respectively) than the standard urinalysis (64.9 and 51.1%, respectively) (P < 0.05). The accuracy, specificity and likelihood ratio of hemocytometer WBC counts were also greater than that of standard UA (88.7, 89.6 and 8.08% vs. 84.3, 88.1 and 5.44%). CONCLUSION: Hemocytometer WBC counts provide more valid and precise prediction of UTI in febrile infants than standard UA. The presence of > or =10 WBC/microl in suprapubic aspiration specimens is the optimum cutoff value for identifying febrile infants for whom urine culture is warranted.


Assuntos
Urinálise/métodos , Infecções Urinárias/diagnóstico , Distribuição de Qui-Quadrado , Equipamentos e Provisões , Feminino , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Urinálise/instrumentação , Infecções Urinárias/sangue , Infecções Urinárias/urina , Urina/microbiologia
17.
Prenat Diagn ; 20(3): 238-40, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10719329

RESUMO

Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive condition with multiple malformations, mental retardation, and growth failure, results from markedly reduced activity of the final enzyme in the cholesterol biosynthetic pathway, 7-dehydrocholesterol Delta(7)-reductase (DHCR7). We diagnosed SLOS in a fetus following intrauterine demise at 32 weeks' gestation. Chorionic villus (CV) sampling had been performed at 30 weeks because oligohydramnios and atrioventricular septal defect were noted on fetal ultrasound. On fetal post-mortem examination, a midline U-shaped soft palate cleft, micrognathia, postaxial polydactyly of the fingers with single transverse palmar creases bilaterally, and cutaneous syndactyly of toes two-three bilaterally suggested SLOS. We hypothesized that SLOS could be confirmed by analysis of tissue sterols despite extensive autolysis, and by measurement of enzyme activity in CV cells. Measurement of DHCR7 activity in CV cells was undertaken using ergosterol as a substrate. CV cells were unable to convert any ergosterol to brassicasterol after a 72 h incubation period while control CV cells reduced 12.6-71.8% of ergosterol to brassciasterol in a 72 h period. SLOS was confirmed by measurement of elevated 7-dehydrocholesterol (7-DHC) in the CV cells. Measurements of sterols were made in multiple fetal tissues. All tissues analysed showed elevated 7-DHC with markedly increased 7-DHC/cholesterol ratios.


Assuntos
Amostra da Vilosidade Coriônica , Vilosidades Coriônicas/enzimologia , Morte Fetal , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Oxirredutases/deficiência , Síndrome de Smith-Lemli-Opitz/diagnóstico , Esteróis/análise , Adulto , Colesterol/análise , Desidrocolesteróis/análise , Ergosterol/metabolismo , Feminino , Idade Gestacional , Humanos , Oxirredutases/análise , Oxirredutases/metabolismo , Gravidez , Ultrassonografia Pré-Natal
18.
Pediatrics ; 105(2): E20, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10654980

RESUMO

OBJECTIVE: To assess the usefulness of laboratory parameters, including peripheral white blood cell (WBC) count, C-reactive protein (CRP) concentration, erythrocyte sedimentation rate (ESR), and microscopic urinalysis (UA), for identifying febrile infants younger than 8 weeks of age at risk for urinary tract infection (UTI), and comparison of standard UA and hemocytometer WBC counts for predicting the presence of UTI. METHODS: A total of 162 febrile children <8 weeks of age were enrolled in this prospective study. All underwent clinical evaluation and laboratory investigation, including WBC count and differential; ESR; CRP; blood culture; a lumbar puncture for cell count and differential, glucose level, protein level, Gram stain, and culture; and a UA and urine culture. All urine specimens were obtained by suprapubic aspiration and microscopically analyzed with standard UA as well as with hemocytometer WBC counts. Quantitative urine cultures were performed. Sensitivity, specificity, accuracy, likelihood ratios, and receiver operating characteristic (ROC) curves were determined for each of the screening tests. RESULTS: There were 22 positive urine culture results of at least 100 colony-forming unit/mL. Eighteen of these 22 patients were males, and all were uncircumcised. There were significant differences for pyuria >/=5 WBCs/hpf, pyuria >/=10 WBC/microL, CRP >20 mg/L, and ESR >30 mm/hour between culture-positive and culture-negative groups (P <.05). The ROC area for hemocytometer WBC count, standard UA, peripheral WBC count, ESR, and CRP concentration were.909 +/-.045,.791 +/-.065,.544 +/-.074,. 787 +/-.060, and.822 +/-.036, respectively. The ROC curve analysis indicates that the CRP, ESR, and standard UA were powerful but imperfect tools with which to discriminate for UTI in potentially infected neonates. Hemocytometer WBC counts had the highest sensitivity, specificity, accuracy, and likelihood ratios for identifying very young infants with positive urine culture results. For all assessments, hemocytometer WBC counts were significantly different, compared with the standard urinalysis. ESR, CRP, and peripheral WBC counts were not helpful in identifying UTI in febrile infants. CONCLUSION: UTI had a prevalence of 13.6% in febrile infants <8 weeks of age. The CRP, ESR, and standard UA were imperfect tools in discriminating for UTI, and the sensitivity of these laboratory parameters was relatively low. Hemocytometer WBC count was a significantly better predictor of UTI in febrile infants.


Assuntos
Infecções Urinárias/diagnóstico , Feminino , Febre/etiologia , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Masculino , Prevalência , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Urinálise , Infecções Urinárias/complicações
19.
J Gastroenterol ; 34(5): 626-8, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10535493

RESUMO

Congenital mesocolic band is an uncommon aberration in the development of the mesentery. Large-bowel obstruction secondary to adhesion and/or congenital band is very rare in children. A 6-month-old male infant who had no history of previous surgery was admitted with unremitting crying. A barium enema showed extraintestinal compression of the sigmoid colon. Laparotomy revealed an adhesive mesocolic band compressing the proximal part of the sigmoid colon. The band was lysed. The patient has remained asymptomatic since the procedure.


Assuntos
Obstrução Intestinal/etiologia , Mesentério/anormalidades , Doenças do Colo Sigmoide/etiologia , Diagnóstico Diferencial , Anormalidades do Sistema Digestório/diagnóstico , Humanos , Lactente , Obstrução Intestinal/diagnóstico , Obstrução Intestinal/cirurgia , Laparotomia , Masculino , Doenças do Colo Sigmoide/diagnóstico , Doenças do Colo Sigmoide/cirurgia , Aderências Teciduais/diagnóstico , Aderências Teciduais/etiologia , Aderências Teciduais/cirurgia
20.
Pediatr Neurol ; 20(1): 66-9, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10029265

RESUMO

The authors report serial technetium-99m hexamethylpropylene-amine-oxime brain single photon emission computed tomography (SPECT) findings in two infants with Gaucher's disease type 2. Detailed neurologic and laboratory examinations, including bone marrow biopsies and enzymatic assays, were described. Serial brain magnetic resonance imaging studies in one patient illustrated the progressive cerebral atrophy in the frontal and temporal lobes. The SPECT in both cases demonstrated positive findings of initial scattered hypoperfusion, with extending to hypoperfusion of the entire cerebrum after 4 months of clinical deterioration. These changes in the SPECT findings may reflect progressive degeneration of the cerebrum in Gaucher's disease type 2. Brain SPECT may provide useful information on cerebral flow and metabolic distribution corresponding to the neurologic deficits of neuronopathic Gaucher's disease.


Assuntos
Encéfalo/diagnóstico por imagem , Doença de Gaucher/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Atrofia/diagnóstico por imagem , Encéfalo/patologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Circulação Cerebrovascular , Progressão da Doença , Humanos , Lactente , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...