Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
J Surg Case Rep ; 2024(3): rjae116, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38463742

RESUMO

Skin burn injury from light cables is a rare complication of laparoscopic surgery, but it can be severe and distressing for both the patient and the surgeon. A case report of skin burns due to laparoscopic light source is presented in this article, followed by an experimental trial to confirm the findings, and review of literature. The light source is usually connected to the camera to give adequate light inside the abdominal cavity for visualization of the internal organs, and hence, safe surgery. The light source should deliver cool light to prevent any burn from heat to skin or internal organs, but in fact, it is not usually cool and can reach high temperatures. Precautions and recommendations to avoid skin burns due to the light source are included. Surgeons should be aware of burns from light sources in laparoscopic surgery and take precautions to prevent them.

2.
J Robot Surg ; 18(1): 43, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38236452

RESUMO

Robotic surgery started nearly 30 years ago. It has achieved telepresence and the performance of repetitive, precise, and accurate tasks. The "master-slave" robotic system allows control of manipulators by surgeon at distant site. Robotic surgical fingers were developed to allow surgeons to move them with accuracy through sensors fixed on surgeon's hand. Also, haptic sensors were developed to allow transmission of sensation from robotic finger to surgeon's finger. A complete system of a, 3D printed by a stereolithography (SLA) 3D printer, robotic surgical finger with haptic feedback system is proposed. The developed system includes a master glove that controls the motion of a 3DOF robotic slave finger while getting haptic feedback of force/pressure exerted on it. The precise control of the slave robotic finger was achieved by applying a Proportional Integral and Derivative (PID), fast and robust, control algorithm using an Arduino based hardware and software module. The individual joint angles, metacarpophalangeal joint (MCP) and proximal interphalangeal joint (PIP), and wrist were measured using rotatory and inertial sensors respectively. The degree of movement for MCP, PIP, and Wrist joints were measured to be 0-86°, 0-71°, and 0-89° respectively. Motion to the robotic finger is mimicked by a glove motion requiring minimal learning curve for the device. The collected data for the slave motion is in good agreement with the master-glove motion data. The vibro-tactile haptic feedback system was developed to distinguish between three different materials to mimic human flesh, tumor, and bone. The master-slave system using robotic surgical finger with good simultaneous movement to surgeon's finger and good haptic sensation will provide the surgeon with the opportunity to perform finger dissection in laparoscopic and robotic surgery, as it used to be in open surgery. 3D bio printing will make this process even cheaper with the added advantage of making surgical tools locally according to the need of the surgery. An ongoing work is to develop silicone based 8 mm robotic surgical finger with multiple type haptic feedback.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Retroalimentação , Tecnologia Háptica , Extremidade Superior
3.
Prev Med Rep ; 36: 102440, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37810267

RESUMO

People who smoke menthol cigarettes, particularly those who are non-Hispanic Black/African American, are less likely to achieve successful smoking cessation compared with people who smoke non-menthol cigarettes. This study examined the 2003-2019 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) harmonized data to estimate cross-sectional trends in cigarette smoking cessation among U.S. adults, stratified by menthol cigarette use, race/ethnicity, sex, and age. The analytic sample included respondents who smoked for ≥ 2 years (current users and former users who reported quitting during the past year). We tested cessation trends using orthogonal polynomial contrasts for overall, menthol, and non-menthol smoking cessation prevalence and stratified by race/ethnicity, sex, and age in logistic regression models. We also analyzed the 2018-2019 non-harmonized TUS-CPS data among recent quitters to examine differences in characteristics (e.g., demographic characteristics, smoking frequency, use of smoking cessation aids, switching to other tobacco products) by menthol cigarette use. We observed significant linear changes in prevalence trends for overall cigarette smoking cessation, menthol smoking cessation, and non-menthol smoking cessation (p < 0.0001 for all linear trends), and changes in menthol cessation among non-Hispanic White and non-Hispanic Other race/ethnicity categories during 2003-2019. In the 2018-2019 wave, we observed differences in menthol status for sex, race/ethnicity, age, and educational attainment. We did not observe differences for other characteristics. We observed changes in overall cigarette smoking cessation, menthol, and non-menthol smoking cessation prevalence during the study period; however, gains in cigarette smoking cessation were not experienced among non-Hispanic Black/African American adults who smoke.

4.
Nicotine Tob Res ; 25(9): 1610-1613, 2023 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-37279928

RESUMO

INTRODUCTION: This manuscript examines prevalence of awareness and use of nicotine pouches among U.S. middle and high school students by sociodemographic characteristics and other tobacco product use and characterizes nicotine pouch and other tobacco product use behaviors among current nicotine pouch users. AIMS AND METHODS: Data are from the 2021 National Tobacco Youth Survey, a cross-sectional, school-based survey of middle and high school students (N = 20 413; overall response rate: 44.6%), which included questions on nicotine pouches in 2021 for the first time. Prevalence estimates, 95% confidence intervals, and estimated population counts were assessed for nicotine pouch awareness, ever use, and current (past 30 days) use, and for use behaviors related to nicotine pouches (frequency of use, flavor(s) used) and other tobacco products (ever, current, frequency of use) among current nicotine pouch users. RESULTS: Over one-third of students (35.5%) had ever heard of nicotine pouches. An estimated 1.9% (490 000) reported ever using them, while 0.8% (200 000) reported current use. Among current nicotine pouch users, 61.6% reported flavored nicotine pouch use, 64.2% reported current e-cigarette use, and 52.6% used multiple (≥2) tobacco products. Current use of nicotine pouches was common among current smokeless tobacco users (41.3%). CONCLUSIONS: Overall, in 2021, while relatively few students had ever tried nicotine pouches or currently used them, more than one-third had heard of them. Current nicotine pouch users tended to use other tobacco products, particularly e-cigarettes and smokeless tobacco. Given previous rapid increases in youth uptake of e-cigarettes, it is important to continue monitoring nicotine pouch use among young people. IMPLICATIONS: This study's findings provide an important baseline for future monitoring of nicotine pouch awareness and use among middle and high school students. Emerging tobacco products, particularly those that are flavored, widely available, discreet, and inexpensive have the potential to attract youth. Given the potential of these products to appeal to young people, ongoing monitoring of nicotine pouch use behaviors is important to inform public health and regulatory efforts.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Humanos , Adolescente , Estados Unidos/epidemiologia , Nicotina , Estudos Transversais , Uso de Tabaco/epidemiologia
5.
Nicotine Tob Res ; 25(4): 718-728, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36239224

RESUMO

INTRODUCTION: Despite its overall decline in the United States, trends in cigarette smoking could vary by intersection with demographic characteristics. We explored trends in education-related disparities in current smoking among U.S. adults by race (Black or African American and White), sex, and U.S. census region. AIMS AND METHODS: Data were from U.S. civilian non-institutionalized adults (aged ≥18 years) who self-identified as Black or African American and White and participated in the 1995-2019 Tobacco Use Supplement to the Current Population Survey. We estimated average annual percent changes in current cigarette smoking by the intersections of race, sex, census region, and educational attainment. We calculated educated-related prevalence differences in current cigarette smoking by subtracting the prevalence of bachelor's degrees from that of

Assuntos
Negro ou Afro-Americano , Fumar Cigarros , Escolaridade , Disparidades nos Níveis de Saúde , Brancos , Adulto , Feminino , Humanos , Masculino , Fumar Cigarros/epidemiologia , Estudos Transversais , Prevalência , Inquéritos e Questionários , Estados Unidos/epidemiologia
6.
Int J STD AIDS ; 33(2): 186-192, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34872392

RESUMO

INTRODUCTION: We assessed reproductive intentions and associated characteristics among men enrolled in the Sustainable Health Center Implementation pre-exposure prophylaxis (PrEP) Pilot (SHIPP) Study. METHODS: We analyzed baseline data from 1275 men who self-identified as gay or bisexual and participated in the SHIPP study. SHIPP was a cohort study of PrEP implementation in five community health centers in Chicago, Jackson, Philadelphia, and Washington, D.C. conducted from 2014 to 2016. Participants completed audio computer-assisted self-interviews querying intentions to have a child in the future. We estimated the association between participants' reproductive intentions and their characteristics using Poisson regression models. RESULTS: Approximately 47% of participants indicated their intentions to have a child. Black/non-Hispanic (aPR = 1.40; 95% CI: 1.10-1.78) and other/non-Hispanic participants (aPR = 1.40; 95% CI: 1.01-1.93) were more likely to report intentions to have a child than white/non-Hispanic participants. Participants were less likely to report intentions to have children as age increased (18-29 years, reference group; 30-39 years, aPR = 0.80, 95% CI: 0.64-0.99; 40-49 years, aPR = 0.49, 95% CI: 0.33-0.72; 50+ years, aPR = 0.07, 95% CI: 0.02-0.21). CONCLUSIONS: Clinicians offering PrEP to black and other/non-Hispanic gay and bisexual men should assess their reproductive intentions as family-planning counseling may be an opportunity to introduce PrEP to HIV-negative gay and bisexual men.


Assuntos
Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Adolescente , Adulto , Criança , Estudos de Coortes , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Homossexualidade Masculina/psicologia , Humanos , Intenção , Masculino , Projetos Piloto , Adulto Jovem
7.
AIDS Behav ; 25(9): 2985-2991, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33523345

RESUMO

The number of new HIV diagnoses is highest in the South. Many persons who might benefit from pre-exposure prophylaxis (PrEP) are not engaged in the HIV PrEP continuum of care. We analyzed National HIV Behavioral Surveillance data to assess engagement in the PrEP continuum of care among persons with increased HIV risk. We compared PrEP awareness, discussion with a clinical provider, and use among persons living in the South to those living elsewhere in the United States. PrEP awareness was lowest among heterosexual persons (7%), highest among men who have sex with men (85%), and 26% among persons who inject drugs. PrEP use was low among each population (≤ 35% for all cycles). There was limited evidence of differences in PrEP use between persons in southern and non-southern U.S. Efforts are needed to increase use of PrEP among each of the groups with increased HIV risk.


RESUMEN: El número de nuevos diagnósticos de virus de la inmunodeficiencia humana (VIH) es más alto en el sur. Muchas personas que podrían beneficiarse de la profilaxis preexposición (PrEP) no participan en la VIH-PrEP continuidad de la atención. Analizamos datos del Sistema Nacional de Vigilancia del Comportamiento Relacionado con el VIH (conocido en inglés como National HIV Behavioral Surveillance System) para evaluar la participación en la PrEP continuidad de la atención en personas con mayor riesgo de contraer el VIH. Comparamos concientización de PrEP, discusión con un proveedor clínico, y uso entre personas que viven en el sur con las personas que viven en otras partes de los Estados Unidos. Concientización de PrEP fue más baja entre personas heterosexuales (7%), más alta entre hombres que tienen relaciones sexuales con hombres (91%), y 26% entre personas que se inyectan drogas. Utilización de PrEP fue baja para todas las poblaciones (≤35% para todos los ciclos). La evidencia de diferencias en el uso de PrEP entre personas que viven en el sur con personas que no viven en el sur de los Estados Unidos fue limitada. Se necesitan esfuerzos para aumentar el uso de PrEP entre estos grupos con más riesgo de contraer el VIH.


Assuntos
Fármacos Anti-HIV , Usuários de Drogas , Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Abuso de Substâncias por Via Intravenosa , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Homossexualidade Masculina , Humanos , Masculino , Abuso de Substâncias por Via Intravenosa/tratamento farmacológico , Abuso de Substâncias por Via Intravenosa/epidemiologia , Estados Unidos/epidemiologia
8.
AIDS Behav ; 25(4): 1267-1275, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33201428

RESUMO

Few studies have assessed providers' intent of prescribing PrEP in the future. We analyzed cross-sectional web-based surveys to estimate trends from 2016 to 2020 in PrEP awareness and prescribing behaviors in the United States among primary care providers. Multivariable logistic regression was used to estimate prevalence of PrEP awareness, prescribing behaviors, and likelihood of prescribing PrEP in the next 12 months. The adjusted prevalence for PrEP awareness was significantly higher in 2019 (93.7%, 95% CI 91.9%, 95.2%) compared to 2018 (88.1%, 95% CI 85.5%, 90.3%). The adjusted prevalence for prescribing PrEP was significantly higher in 2019 (16.4%, 95% CI 13.6%, 19.6%) and 2020 (15.6%, 95% CI 13.0%, 18.7%) compared to 2018 (12.2%, 95% CI 10.0%, 14.7%). Practicing in the West and regularly screening for HIV were associated with higher PrEP awareness and provision. Studies should examine factors associated with PrEP provision for groups with increased risk for HIV.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Fármacos Anti-HIV/uso terapêutico , Estudos Transversais , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Padrões de Prática Médica , Atenção Primária à Saúde , Inquéritos e Questionários , Estados Unidos/epidemiologia
9.
AIDS Educ Prev ; 32(2): 102-S6, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32539481

RESUMO

Men and women of color have had low pre-exposure prophylaxis (PrEP) uptake. How one's preferred source of health information shapes attitudes toward PrEP is unclear. We conducted cross-sectional surveys to assess changes in PrEP awareness, knowledge, and attitudes, trusted sources for PrEP information, and associations between trusted source of information and PrEP knowledge and attitudes. Participants were recruited from six areas served by community health centers in Chicago, IL (two health centers); Jackson, MS; Newark, NJ; Philadelphia, PA; and Washington, D.C. during June-September 2015 (n = 160) and June-September 2016 (n = 200). Participants were Black (74%), heterosexual (81%), and largely unaware of PrEP (72%). Participants who trusted health experts and community organizations for PrEP information had lower percentages of agreeing with statements indicative of negative PrEP attitudes. Interventions that increase PrEP awareness as well as knowledge and favorable attitudes might help increase PrEP use in communities with high HIV prevalence.


Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Infecções por HIV/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Confiança , Adulto , Estudos Transversais , Feminino , Infecções por HIV/psicologia , Heterossexualidade , Humanos , Masculino , Profilaxia Pré-Exposição/métodos , Inquéritos e Questionários , Estados Unidos
10.
Curr Drug Deliv ; 16(7): 628-636, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31385769

RESUMO

BACKGROUND: The tocopherol-based excipient, TPM, when incorporated into a medium-chain triglyceride (MCT)-based lipid formulation, has been previously shown to improve the solubilization of Coenzyme Q10 (CoQ10) during in vitro digestion which is strongly correlated with enhanced exposure in vivo. METHODS: The current study aimed to gain further understanding of the MCT + TPM co-formulation, by assessing the formulation performance under fasted and fed in vitro digestion conditions, with different drug and excipient loading levels. Natural and synthetic-derived TPM were equivalent, and with d-α- tocopherol polyethylene glycol 1000 succinate (TPGS) outperformed other derivatives in enhancing the solubilisation of CoQ10 during digestion. RESULT: Fed conditions significantly improved the solubility of CoQ10 during in vitro digestion of the formulation in comparison with fasted conditions. The addition of TPM at 10% (w/w) of the total MCT + TPM provided optimal performance in terms of CoQ10 solubilization during digestion. CONCLUSION: The results further highlights the potential of TPM as an additive in lipid formulations to improve the solubilization and oral bioavailability of poorly water-soluble compounds.


Assuntos
Excipientes/química , Triglicerídeos/química , Ubiquinona/análogos & derivados , Vitamina E/química , Digestão , Jejum/metabolismo , Intestino Delgado/metabolismo , Fosforilação , Solubilidade , Ubiquinona/química
11.
Cureus ; 11(2): e4045, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-31016073

RESUMO

Embolic protection devices are used to minimize the risk of stroke by preventing the migration of emboli during carotid artery stenting (CAS). After the successful conclusion of the CAS procedure, these devices are meant to be retrieved. Sometimes retrieval of the filter can be difficult. This difficulty in retrieval can be due to multiple factors such as incomplete stent expansion, stent fracture, vasospasm, and vessel tortuosity causing pseudostenoses. In this case report, an under-expanded proximal carotid stent strut contributed to the filter not being retrievable in spite of maneuvers to retrieve the filter. An innovative approach was used; a coronary guide extension catheter was used to enhance support and balloon-assisted tracking of the extension catheter then permitted advancement of the retrieval device and ultimate retrieval of the filter. This technique to retrieve a carotid filter has not been previously described in the literature.

12.
Chemistry ; 21(36): 12702-8, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26179611

RESUMO

A novel approach is used to synthesize a stable, ligated copper(I) carbene in the gas phase that is capable of typical metal carbenoid chemistry. However, it is shown that copper(I) carbenes generally undergo rapid unimolecular rearrangements including insertions into copper-ligand bonds and Wolff rearrangements. The results indicate that most copper(I) carbenes are inherently unstable and would not be viable intermediates in condensed-phase applications; an alternative intermediate that is less prone to rearrangements is required. Computational data suggest that ylides formed by the complexation of the carbene with solvent or other weak nucleophiles are viable intermediates in the reactions of copper(I) carbenes.

13.
Biosens Bioelectron ; 52: 129-35, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24035857

RESUMO

Legionellosis has been and continues to be a life-threatening disease worldwide, even in developed countries. Given the severity and unpredictability of Legionellosis outbreaks, developing a rapid, highly specific, and sensitive detection method is thus of great pertinence. In this paper, we demonstrate that sub-femtomole levels of 16s rRNA from pathogenic Legionella pneumophila can be timely and effectively detected using an appropriate designed capture, detector probes, and a QD SPRi signal amplification strategy. To achieve specific and sensitive detection, optimal hybridization conditions and parameters were implemented. Among these parameters, fragmentation of the 16s rRNA and further signal amplification by QDs were found to be the main parameters contributing to signal enhancement. The appropriate design of the detector probes also increased the sensitivity of the detection system, mainly due to secondary structure of 16s rRNA. The use of 16s rRNA from L. pneumophila allowed for the detection of metabolically active pathogens with high sensitivity. Detection of 16s rRNA in solutions as diluted as 1 pM at 450 µL (0.45 femtomole) was achieved in less than 3h, making our approach suitable for the direct, timely, and effective detection of L. pneumophila within man-made water systems.


Assuntos
Técnicas Biossensoriais/métodos , Legionella pneumophila/isolamento & purificação , RNA Ribossômico 16S/isolamento & purificação , Ressonância de Plasmônio de Superfície/métodos , Humanos , Legionella pneumophila/genética , Masculino , Hibridização de Ácido Nucleico
14.
Expert Opin Drug Deliv ; 10(11): 1471-82, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23713443

RESUMO

OBJECTIVES: Oral health is influenced by the mouth's resident microorganisms. Dental caries and periodontitis are oral disorders caused by imbalances in the oral microbiota. Probiotics have potential for the prevention and treatment of oral disorders. Current formulations, including supplements and foods, have limitations for oral delivery including short storage time, low residence time in the mouth, effects on food consistency, and low patient compliance. Oral thin films (OTFs) may be efficient in delivering probiotics to the mouth. This research aims to develop a novel carboxymethyl cellulose (CMC)-probiotic-OTF to deliver probiotics for the treatment/prevention of oral disorders. METHODS: CMC-OTFs were developed with varying CMC concentration (1.25 - 10 mg/mL), weight (5 - 40 g), thickness (16 - 262 µm), hygroscopicity (30.8 - 78.9 mg/cm(2) film), and dissolving time (135 - 600 s). The 10 g 5 mg/mL CMC-OTF was selected and used to incorporate Lactobacillus fermentum NCIMB 5221 (6.75 × 10(8) cells/film), a probiotic with anti-inflammatory potential for periodontitis treatment and capable of inhibiting microorganisms responsible for dental caries and oral candidiasis. RESULTS: The CMC-OTF maintained probiotic viability and antioxidant activity following 150 days of storage with a production of 549.52 ± 26.08 µM Trolox equivalents. CONCLUSION: This research shows the successful development and characterization of a novel probiotic-CMC-OTF with potential as an oral health biotherapeutic.


Assuntos
Carboximetilcelulose Sódica/química , Sistemas de Liberação de Medicamentos , Limosilactobacillus fermentum , Probióticos/administração & dosagem , Cárie Dentária/prevenção & controle , Humanos , Boca , Saúde Bucal , Periodontite/prevenção & controle
15.
Biomaterials ; 32(6): 1536-42, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21093908

RESUMO

Human pancreatic islet in vitro culture is very challenging and requires the presence of various extra cellular matrix (ECM) components in a three-dimensional environment, which provides mechanical and biological support. The development of such an environment is vital in providing favourable conditions to preserve human islets in long-term culture. In this study, we investigated the effects of human islet culture within various three-dimensional environments; collagen I gel, collagen I gel supplemented with ECM components fibronectin and collagen IV, and microfabricated scaffold with ECM-supplemented gel. The cultured human islets were analyzed for functionality, gene expression and hormone content following long-term in vitro culture. It was clear the incorporation of ECM components within the three-dimensional support improved prolonged culture. However, long-term and highly uniform human islet culture within a microfabricated scaffold, with controlled pore structures, coupled with the presence of ECM components, displayed an insulin release profile similar to freshly isolated islets, yielding a stimulation index of approximately 1.8. Moreover, gene expression was markedly increased for all pancreatic genes, giving a approximately 50-fold elevation of insulin gene expression with respect to suspension culture. The distribution and presence of pancreatic hormones was also highly elevated. These findings provide a platform for the long-term maintenance and preservation of human pancreatic islets in vitro.


Assuntos
Ilhotas Pancreáticas/citologia , Alicerces Teciduais , Células Cultivadas , Matriz Extracelular/química , Imunofluorescência , Humanos , Ilhotas Pancreáticas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Case Rep Cardiol ; 2011: 792938, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24826229

RESUMO

We describe the case of a 64-year-old male initially presenting with presyncope and bradycardia, without any anginal symptoms or objective evidence of myocardial ischemia. A stress test induced no physical symptoms but revealed a left bundle branch block with multiple preventricular contractions on electrocardiogram. Subsequent catheterization revealed severe obstructive disease throughout the coronary arteries. He was treated percutaneously on two separate heart catheterizations. The presyncope and bradycardia resolved after reperfusion of the posterior descending artery.

17.
Org Lett ; 12(4): 676-9, 2010 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-20088560

RESUMO

The rates and products from the gas-phase reactions of Co(III) salens with ethyl and t-butyl diazoacetate were examined. Addition with loss of N(2) is observed, and substituent effects as well as DFT calculations indicate that addition is rate determining. Calculations suggest that the carbene species involve novel structures with the carbenic carbon bridging between the cobalt and a salen oxygen. Collision-induced dissociation leads to an unusual, bridged metal/ketene species.

18.
BMJ Case Rep ; 20102010 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-22791578

RESUMO

Presacral tumours represent a heterogeneous group of predominantly benign and occasionally malignant neoplasms. These tumours, though rare, frequently present either incidentally or with vague symptoms. Schwannomas of the presacral region are one variant described as benign tumours of neurogenic origin. The case of a large presacral schwannoma in a 26-year-old man, who was treated for irritable bowel syndrome for 4 years, is presented. The patient presented with intermittent constipation, a feeling of incomplete evacuation of the bowel and vague abdominal discomfort relieved by defecation. The symptomatology worsened and constipation became frequent, and the patient experienced increased urinary frequency. Baseline investigations were normal and ultrasonography of the abdomen revealed a pelvic mass, which on CT scanning was revealed to be a large retrorectal mass. The tumour was resected and histology revealed it to be a schwannoma. This unique case is presented to emphasise that irritable bowel syndrome must be a diagnosis of exclusion, especially if atypical symptoms are present.


Assuntos
Diagnóstico Tardio , Erros de Diagnóstico , Síndrome do Intestino Irritável/diagnóstico , Neurilemoma/diagnóstico , Adulto , Constipação Intestinal/etiologia , Diagnóstico Diferencial , Humanos , Masculino , Neurilemoma/complicações , Região Sacrococcígea
19.
J Oral Rehabil ; 35(10): 722-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18482344

RESUMO

When a certain bite force is applied during unilateral chewing, the combination of jaw elevator muscle activities is different than when a comparable force is applied in unilateral isometric biting, e.g. on a force transducer. Masticatory peak force is generated in a nearly isometric phase of the chewing cycle, with a jaw gape of about 1 mm. In contrast, peak force in isometric biting on force measuring equipment usually induces jaw gapes of 6 mm or even more. Therefore, we tested the hypothesis that the jaw gape influences relative activation of elevator muscles in unilateral isometric biting. We further examined whether such influence could explain the different activity combinations of chewing and isometric biting. In thirty asymptomatic males, masseter and temporalis activities were recorded during intermittent isometric biting with jaw gapes of 6, 5, 3, 2 and 1 mm and during unilateral chewing. Activity combinations were described by working/balancing ratios and by temporalis/masseter ratios. With decreasing jaw gape the working/balancing ratio of the posterior temporalis decreased (P < 0.002) while that of the masseter increased (P < 0.001). Likewise, the temporalis/masseter ratio on the balancing side increased (P < 0.001). With decreasing jaw gape, activity ratios of isometric biting approached ratios of chewing. We conclude that: (i) relative jaw muscle activation in isometric biting depends on the jaw gape, (ii) relative muscle activation in chewing resembles relative activation of isometric biting with a small 'chewing-like' gape. This suggests that characteristic activity combinations in chewing are mainly a result of the approximately isometric contraction during the slow closing phase of the chewing cycle.


Assuntos
Força de Mordida , Arcada Osseodentária/fisiologia , Mastigação/fisiologia , Músculos da Mastigação/fisiologia , Adulto , Eletromiografia/métodos , Humanos , Contração Isométrica/fisiologia , Masculino , Músculo Masseter/fisiologia , Músculo Temporal/fisiologia , Adulto Jovem
20.
J Biomed Biotechnol ; 1(3): 114-121, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12488604

RESUMO

We have identified four different mutations causing leukocyte adhesion Deficiency (LAD) in the ITGB2 gene of patients from a highly inbred population. Two were novel single-bp deletions (1497delG and 1920delG) causing frame shift and the two others were the missense mutations G284S and R593C. In our study, the G284S was a recurrent mutation while the R593C occurred de novo. We have also characterized a novel Xba1 polymorphic site located at the 5' end of the ITGB2 locus. Family studies showed that the 1497delG mutation segregated with this marker and the intragenic AvaII polymorphic marker, suggesting the presence of a founder effect. The observation of a heterogeneous spectrum including de novo and recurrent mutations causing LAD in a highly inbred population is rather unexpected. In view of the literature published on the molecular genetics of LAD and considering the ethnic origin of the patients studied, our findings confirm the heterogeneity of the mutations causing LAD and point out potential mutational hot spots in the ITGB2 gene.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA