RESUMO
There are no studies that have compared the clinical and radiographic status around immediately loaded (IL) and conventional loaded (CL) implants placed in patients with type 2 diabetes mellitus (T2DM). The aim was to compare the clinical and radiographic status around IL and CL implants placed in T2DM patients. One hundred and eight diabetic patients [55 with IL implants (Group 1) and 53 with CL implants (Group 2)] were included in this cross-sectional study. All implants were placed in healed sites in the maxillary and mandibular premolar and molar regions and supported single restorations. All patients underwent full mouth mechanical debridement biannually. Haemoglobin A1c (HbA1c) levels, clinical [bleeding on probing (BOP) and probing depth (PD) ≥ 4 mm] and radiographic [crestal bone loss (CBL)] peri-implant parameters were measured for both groups at 12- and 24-month follow-up. Group comparisons were performed using the Mann-Whitney U-test (P < 0·05). The mean age and duration of T2DM in groups 1 and 2 were 50·6 ± 2·2 and 51·8 ± 1·7 years, and 9·2 ± 2·4 and 8·5 ± 0·4 years, respectively. At 12- and 24-month follow-up, the mean HbA1c levels in groups 1 and 2 were 5·4% (4·8-5·5%) and 5·1% (4·7-5·4%) and 5·1% (4·7-5·2%) and 4·9% (4·5-5·2%), respectively. At 12- and 24-month follow-up, there was no statistically significant difference in peri-implant BOP, PD and CBL in both groups. It was concluded that clinical and radiographic status is comparable around IL and CL implants placed in patients with T2DM. The contribution of careful case selection, oral hygiene maintenance and glycaemic control is emphasised.
Assuntos
Implantes Dentários para Um Único Dente , Diabetes Mellitus Tipo 2/fisiopatologia , Gengiva/patologia , Hiperglicemia/complicações , Carga Imediata em Implante Dentário/métodos , Radiografia Dentária , Estudos Transversais , Assistência Odontológica para Doentes Crônicos , Prótese Dentária Fixada por Implante , Feminino , Seguimentos , Gengiva/diagnóstico por imagem , Humanos , Hiperglicemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
BACKGROUND: Our previous research (Pediatrics 2010:126) found a strong association between caregiver oral health literacy (OHL) and children's oral health status; however, we found a weak association with oral health behaviors (OHBs). We hypothesize that this may be due to social desirability bias (SDB). Our objectives were to compare caregivers' responses to traditional OHB items and newer SDB-modulating items, and to examine the association of caregiver literacy with OHBs. METHODS: We performed a cross-sectional study of 102 caregiver-child dyads, collecting data for OHBs using both traditional and new SDB-modulating items. We measured OHL using REALD-30, a validated word recognition test. We relied upon percent agreement and Cohen's kappa (k) to quantify the concordance in caregivers' responses and multivariate log-binomial regression to estimate the impact of OHL on OHBs. RESULTS: Caregivers' mean REALD-30 score was 20.7 (SD = 6.0), range 1-30. We found an association between OHL and 4 of 8 OHBs examined. A subset of behavior questions compared traditional versus SDB-modulating items: history of bottle-feeding: agreement = 95%, k = 0.83 (95% CL:0.68,0.99); daily tooth brushing: agreement = 78%, k = 0.25 (95% CL:0.04,0.46); fluoridated toothpaste use: agreement = 88%, k = 0.67 (95% CL:0.49,0.85). After controlling for caregivers' race, marital status and study site, higher literacy scores remained associated with a decreased prevalence of parental report of "decided not brush the child's teeth because it would be frustrating". CONCLUSIONS: Agreement between responses was high for 2 of 3 behavior items. Item 3 (tooth brushing frequency) revealed discordance, likely due to SDB. Use of the SDB-modulating items appears to yield a better estimate of OHB.
Assuntos
Cuidadores/psicologia , Comportamento Infantil , Higiene Bucal/psicologia , Preconceito , Desejabilidade Social , Análise de Variância , Cuidadores/estatística & dados numéricos , Criança , Estudos Transversais , Escolaridade , Feminino , Comportamentos Relacionados com a Saúde , Letramento em Saúde , HumanosRESUMO
OBJECTIVES: We examined the associations of oral health literacy (OHL) with oral health status (OHS) and dental neglect (DN), and we explored whether self-efficacy mediated or modified these associations. METHODS: We used interview data collected from 1280 female clients of the Special Supplemental Nutrition Program for Women, Infants and Children from 2007 to 2009 as part of the Carolina Oral Health Literacy Project. We measured OHL with a validated word recognition test (REALD-30), and we measured OHS with the self-reported National Health and Nutrition Examination Survey item. Analyses used descriptive, bivariate, and multivariate methods. RESULTS: Less than one third of participants rated their OHS as very good or excellent. Higher OHL was associated with better OHS (for a 10-unit REALD increase: multivariate prevalence ratio = 1.29; 95% confidence interval = 1.08, 1.54). OHL was not correlated with DN, but self-efficacy showed a strong negative correlation with DN. Self-efficacy remained significantly associated with DN in a fully adjusted model that included OHL. CONCLUSIONS: Increased OHL was associated with better OHS but not with DN. Self-efficacy was a strong correlate of DN and may mediate the effects of literacy on OHS.
Assuntos
Letramento em Saúde/estatística & dados numéricos , Saúde Bucal/estatística & dados numéricos , Autoeficácia , Adolescente , Adulto , Fatores Etários , Inquéritos de Saúde Bucal/estatística & dados numéricos , Feminino , Nível de Saúde , Humanos , Fatores Socioeconômicos , Adulto JovemRESUMO
We use both large and small animal models in our pre-clinical evaluation of gene transfer agents (GTAs) for cystic fibrosis (CF) gene therapy. Here, we report the use of a large animal model to assess three non-viral GTAs: 25 kDa-branched polyethyleneimine (PEI), the cationic liposome (GL67A) and compacted DNA nanoparticle formulated with polyethylene glycol-substituted lysine 30-mer. GTAs complexed with plasmids expressing human cystic fibrosis transmembrane conductance regulator (CFTR) complementary DNA were administered to the sheep lung (n=8 per group) by aerosol. All GTAs gave evidence of gene transfer and expression 1 day after treatment. Vector-derived mRNA was expressed in lung tissues, including epithelial cell-enriched bronchial brushing samples, with median group values reaching 1-10% of endogenous CFTR mRNA levels. GL67A gave the highest levels of expression. Human CFTR protein was detected in small airway epithelial cells in some animals treated with GL67A (two out of eight) and PEI (one out of eight). Bronchoalveolar lavage neutrophilia, lung histology and elevated serum haptoglobin levels indicated that gene delivery was associated with mild local and systemic inflammation. Our conclusion was that GL67A was the best non-viral GTA currently available for aerosol delivery to the sheep lung, led to the selection of GL67A as our lead GTA for clinical trials in CF patients.
Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/terapia , Técnicas de Transferência de Genes , Terapia Genética/métodos , Lipossomos/administração & dosagem , Nanopartículas/administração & dosagem , Polietilenoimina/administração & dosagem , Administração por Inalação , Animais , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , DNA Complementar/administração & dosagem , DNA Complementar/genética , Humanos , Polietilenoglicóis , RNA Mensageiro/metabolismo , OvinosRESUMO
BACKGROUND: To investigate the association between oral health literacy (OHL) and oral health-related quality of life (OHRQoL) and explore the racial differences therein among a low-income community-based group of female WIC participants. METHODS: Participants (N = 1,405) enrolled in the Carolina Oral Health Literacy (COHL) study completed the short form of the Oral Health Impact Profile Index (OHIP-14, a measure of OHRQoL) and REALD-30 (a word recognition literacy test). Socio-demographic and self-reported dental attendance data were collected via structured interviews. Severity (cumulative OHIP-14 score) and extent of impact (number of items reported fairly/very often) scores were calculated as measures of OHRQoL. OHL was assessed by the cumulative REALD-30 score. The association of OHL with OHRQoL was examined using descriptive and visual methods, and was quantified using Spearman's rho and zero-inflated negative binomial modeling. RESULTS: The study group included a substantial number of African Americans (AA = 41%) and American Indians (AI = 20%). The sample majority had a high school education or less and a mean age of 26.6 years. One-third of the participants reported at least one oral health impact. The OHIP-14 mean severity and extent scores were 10.6 [95% confidence limits (CL) = 10.0, 11.2] and 1.35 (95% CL = 1.21, 1.50), respectively. OHL scores were distributed normally with mean (standard deviation, SD) REALD-30 of 15.8 (5.3). OHL was weakly associated with OHRQoL: prevalence rho = -0.14 (95% CL = -0.20, -0.08); extent rho = -0.14 (95% CL = -0.19, -0.09); severity rho = -0.10 (95% CL = -0.16, -0.05). "Low" OHL (defined as < 13 REALD-30 score) was associated with worse OHRQoL, with increases in the prevalence of OHIP-14 impacts ranging from 11% for severity to 34% for extent. The inverse association of OHL with OHIP-14 impacts persisted in multivariate analysis: Problem Rate Ratio (PRR) = 0.91 (95% CL = 0.86, 0.98) for one SD change in OHL. Stratification by race revealed effect-measure modification: Whites--PRR = 1.01 (95% CL = 0.91, 1.11); AA--PRR = 0.86 (95% CL = 0.77, 0.96). CONCLUSIONS: Although the inverse association between OHL and OHRQoL across the entire sample was weak, subjects in the "low" OHL group reported significantly more OHRQoL impacts versus those with higher literacy. Our findings indicate that the association between OHL and OHRQoL may be modified by race.
Assuntos
Atitude Frente a Saúde/etnologia , Cuidadores/psicologia , Letramento em Saúde , Saúde Bucal/etnologia , Qualidade de Vida , Adulto , Feminino , Humanos , Entrevistas como Assunto , Análise Multivariada , North Carolina , Pobreza , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: To determine oral health literacy (OHL) levels and explore potential racial differences in a low-income population. METHODS: This was a cross-sectional study of caregiver/child dyads that completed a structured 30-minute in-person interview conducted by two trained interviewers in seven counties in North Carolina. Sociodemographic, OHL, and dental health-related data were collected. OHL was measured with a dental word recognition test [Rapid Estimate of Adult Literacy in Dentistry (REALD-30)]. Descriptive, bivariate, and multivariate methods were used to examine the distribution of OHL and explore racial differences. RESULTS: Of 1658 eligible subjects, 1405 (85 percent) participated and completed the interviews. The analytic sample (N=1280) had mean age 26.5 (standard deviation = 6.9) years with 60 percent having a high school degree or less. OHL varied between racial groups as follows: Whites--mean score = 17.4 (SE = 0.2); African-American (AA)--mean score = 15.3 [standard error (SE) = 0.2]; American Indian (AI)--mean score = 13.7 (SE = 0.3). Multiple linear regression revealed that after controlling for education, county of residence, age, and Hispanic ethnicity, Whites had 2.0 points (95 percent CI = 1.4, 2.6) higher adjusted REALD-30 score versus AA and AI. CONCLUSIONS: Differences in OHL levels between racial groups persisted after adjusting for education and sociodemographic characteristics.
Assuntos
Serviços de Alimentação , Letramento em Saúde , Saúde Bucal , Pobreza , Adolescente , Adulto , Negro ou Afro-Americano , Fatores Etários , Idoso , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Escolaridade , Comportamentos Relacionados com a Saúde , Nível de Saúde , Hispânico ou Latino , Humanos , Indígenas Norte-Americanos , Lactente , Estado Civil , Pessoa de Meia-Idade , North Carolina , Estudos Prospectivos , Características de Residência , Autoeficácia , População Branca , Adulto JovemRESUMO
Iodine has recently been of interest in atmospheric chemistry due to its role in tropospheric ozone depletion, modification of the HO/HO(2) ratio and aerosol nucleation. Gas-phase iodine chemistry is tightly coupled to the aerosol phase through heterogeneous reactions, which are dependent on iodine concentrations and speciation in the aerosol. To date, the only method available for total iodine determination in aerosols is collection on filters by impaction and quantification by neutron activation analysis (NAA). NAA is not widely available to all working groups and is costly to commission. Here, we present a method to determine total iodine concentrations in aerosol impact filter samples by combustion of filter sub-samples (approximately 5 cm(2)) at 1,000 degrees C, trapping in deionised water and quantification by UV/Vis spectroscopy. Both quartz and cellulose filters were analysed from four separate sampling campaigns. The method proved to be sensitive (3sigma = 6 ng absolute iodine approximately 3 pmol m(-3)) precise (RSD approximately 5%) and accurate, as determined by external and standard addition calibrations. Total iodine concentrations ranged from 10 pmol m(-3) over the Southern Ocean to 100 pmol m(-3) over the tropical Atlantic, in agreement with previous estimates. The soluble iodine concentration (extracted with water and measured by ICP-MS) was then subtracted from the total iodine to yield non-water-soluble iodine (NSI). The NSI fraction ranged from 20% to 53% of total iodine, and thus can be significant in some cases.
Assuntos
Aerossóis/análise , Atmosfera/análise , Iodo/análise , Espectrofotometria Ultravioleta , Água/análise , Aerossóis/química , Atmosfera/química , Celulose/química , Temperatura Alta , Iodo/química , Filtros Microporos , Quartzo/química , Água/químicaRESUMO
In the United Kingdom (UK) the estimated prevalence of dental infection involving the supporting bone is 2%, and from 2014-2015 there were 2281 admissions in England alone due to dental abscess. We undertook an analysis of 184 dental abscesses that required surgical drainage, as there is surprisingly little in the literature on the subject. This was a retrospective study of 184 consecutive patients with dental abscesses who were admitted between January 2016 and September 2019. On admission, all patients had orthopantomograms (OPG) and baseline blood tests. Surgical drainage was performed under a general or local anaesthetic and a pus swab sent for culture and sensitivity. The submandibular space was the most commonly involved site and paediatric patients most often presented with buccal space abscesses. A lower molar tooth was the cause in 132 patients. White blood cells (WBC) and C-reactive protein (CRP) were both raised in 63.6% (n=117), but were normal in 4.9% (n=9). The remaining patients had either raised WBC (2.7%) or CRP (28.8%). Streptococcus milleri was the most common organism isolated in 66.6% (n=42). There was no association between CRP or WBC values and duration of hospital stay. Paediatric patients had a shorter duration of admission (1.96 days vs 2.81 days) and significantly lower CRP values (120.9 vs 45.7; p=0.001). The submandibular space was the commonest site involved and mandibular molars the most frequent source of infection. An elevated CRP value appeared to be a more sensitive indicator of infection in this study population. Adult and paediatric patients present in a different manner.
Assuntos
Drenagem , Universidades , Adulto , Criança , Inglaterra , Hospitais de Ensino , Humanos , Estudos Retrospectivos , Reino UnidoRESUMO
The case selection for adult dental extraction under general anaesthesia (GA) is inevitably subjective. A culture of overprescription has implications for patient safety as well as for the limited resources of the National Health Service. We explored the current perceptions and opinions of clinicians in oral and maxillofacial surgery (OMFS) units throughout the UK on various aspects of adult dental extraction under general anaesthesia (DGA) service. An email with an electronic survey link was sent to members of the British Association of Oral and Maxillofacial Surgeons and postgraduate dental deaneries. An institutional response rate of 67.3% was reached (241 clinicians of varying grades from 107 out of 159 oral and maxillofacial surgery units in the UK). There was a general consensus that the culture of demand-driven adult DGA exists and needs to be addressed. However, opinions were divided and varied on how this could be achieved. A small majority (58.1%) were in favour of adult DGA guidelines and this group provided suggestions for selection criteria. Those that did not feel such guidelines would improve the situation were pessimistic of the potential for change in patients' attitude towards DGA. This group cited the poor adherence to other existing guidelines, or suggested alternative ideas to guidelines.
Assuntos
Anestesia Dentária , Anestesia Geral/estatística & dados numéricos , Atitude do Pessoal de Saúde , Odontologia , Extração Dentária , Adulto , Pesquisas sobre Atenção à Saúde , Humanos , Preferência do Paciente , Reino UnidoRESUMO
BACKGROUND: Sub-optimal antibiotic prescribing remains a public health concern in Namibia. The objective was to determine the level and predictors of compliance to guidelines in the prescribing of antibiotics in acute infections at a national referral hospital in Namibia to improve future prescribing. METHODS: An analytical cross-sectional survey design. The clinical records of patients receiving care were reviewed. Prescribing practices were assessed using a self- administered questionnaire with reference to Namibia Standard Treatment Guidelines (NSTG). RESULTS: The majority of prescriptions (62%) complied with the NSTGs; however, lower than national targets (95%). Most prescriptions were empiric and prescribers typically made reference to the NSTG (58%). Diagnosed infections were principally respiratory infections (58%) and penicillins were the most used antibiotics. Good concurrence between signs and symptoms with the diagnosis indicated on the prescription - OR=5.2 (95% CI: 1.4, 19.2), a diagnosis of upper respiratory tract (p=0.001), oral-dental OR=0.1(95% CI: 0.03,0.3) and urogenital infections OR=0.3(95% CI: 0.1,0.95) and the prescribing of penicillins (p=0.001) or combination antibiotics and amphenicols were independent predictors of compliance to the NSTGs. The main behaviours associated with antibiotic prescribing were patient influences, clinical state, and access to guidelines. CONCLUSIONS: Compliance with NSTGs is suboptimal. Prescribing of combination antibiotics, penicillins and diagnosis of oral dental, genitourinary and ear, nose and throat infections were important predictors for NSTG compliance. There is a need to implement antibiotic indicators and stewardship programmes, and ensure access to NSTGs, to improve future antibiotic prescribing in Namibia.
Assuntos
Antibacterianos/administração & dosagem , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/epidemiologia , Fidelidade a Diretrizes/estatística & dados numéricos , Padrões de Prática Médica , Encaminhamento e Consulta , Humanos , Namíbia , Projetos PilotoRESUMO
The objectives of this study were to examine the pattern of association between dental utilization and oral health literacy (OHL). As part of the Carolina Oral Health Literacy Project, clients in the Women, Infants, and Children's Special Supplemental Nutrition Program completed a structured 30-min in-person interview conducted by 2 trained interviewers at 9 sites in 7 counties in North Carolina. Data were collected on clients' OHL, sociodemographics, dental utilization, self-efficacy, and dental knowledge. The outcome, OHL, was measured with a dental word recognition test (30-item Rapid Estimate of Adult Literacy in Dentistry). Descriptive and multiple linear regression methods were used to examine the distribution of OHL and its association with covariates. After adjusting for age, education, race, marital status, self-efficacy, and dental knowledge, multiple linear regression showed that dental utilization was not a significant predictor of OHL (P > 0.05). Under the conditions of this study, dental utilization was not a significant predictor of OHL.
Assuntos
Assistência Odontológica/estatística & dados numéricos , Letramento em Saúde , Saúde Bucal , Adulto , Negro ou Afro-Americano , Fatores Etários , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Lactente , Alfabetização , Estado Civil , North Carolina , Pobreza , Estudos Prospectivos , Autoeficácia , Classe Social , População BrancaRESUMO
We have previously reported that human airway macrophages do not respond to the beta-adrenoceptor agonist isoprenaline. The airway macrophage is known to be derived from the blood monocyte. In this study we have assessed the effect of beta-adrenoceptor stimulation on human monocytes matured into macrophages in vitro, to determine whether the lack of response previously observed in the airway macrophage may be a consequence of differentiation. The release of thromboxane B2 (TXB2) from freshly isolated monocytes stimulated by opsonized zymosan (OPZ) was inhibited by 39.3 +/- 5.5% in the presence of isoprenaline (10(-7) M). However, the response was lost in the monocyte-derived macrophage (MDM), where isoprenaline (10(-7) M) caused only 4.0 +/- 9.3% inhibition of OPZ-stimulated TXB2 release. In contrast forskolin (10(-5) M) inhibited MDM TXB2 release by 36.4 +/- 17.3%, indicating that the adenylyl cyclase was functional. Measurement of adenylyl cyclase activity showed that there was a reduction in the basal level, 17.03 +/- 4.1 to 7.9 +/- 4.6 cyclic AMP pmol/min/mg protein, and NaF (10(-2) M)-induced activity, 116.3 +/- 32.1 to 21.9 +/- 12.6 cyclic AMP pmol/min/mg protein, between freshly isolated monocytes and MDMs, respectively. In addition, there was no change in MDM basal adenylyl cyclase activity on exposure to isoprenaline. Thus we have demonstrated the loss of beta-adrenoceptor function during the maturation of human monocytes to macrophages in vitro, despite a functional adenylyl cyclase system. In this respect the monocyte-derived macrophage is like the airway macrophage.
Assuntos
Isoproterenol/farmacologia , Macrófagos/citologia , Monócitos/citologia , Receptores Adrenérgicos beta/fisiologia , Acetilglucosaminidase/metabolismo , Adenilil Ciclases/metabolismo , Diferenciação Celular , Colforsina/farmacologia , Ativação Enzimática , Humanos , Técnicas In Vitro , Macrófagos/metabolismo , Monócitos/metabolismo , Transdução de Sinais , Fluoreto de Sódio/farmacologia , Tromboxano B2/metabolismo , Zimosan/farmacologiaRESUMO
This case report illustrates an example of when an extraoral approach was successfully used to remove a lower left third molar.
Assuntos
Dente Serotino/cirurgia , Extração Dentária/métodos , Dente Impactado/cirurgia , Adulto , Humanos , Masculino , Mandíbula/cirurgia , Dente Serotino/diagnóstico por imagem , Radiografia , Anquilose Dental/diagnóstico por imagem , Anquilose Dental/cirurgia , Dente Impactado/diagnóstico por imagemRESUMO
Stable complexes of cationic liposomes with plasmid DNA were prepared by (1) including a small amount of poly(ethylene glycol)-phospholipid conjugate or (2) condensing the DNA with polyamines prior to the formation of liposome-plasmid complexes. These preparations were stable for months at 4 degrees C and gave reproducible high transfection activity for in vivo gene delivery after intravenous injection in mice. Under these conditions, the expression of marker gene (luciferase) was primarily in the lungs (reaching values up to 3 ng expression per mg tissue protein), but also in other tissues to a lesser extent. Non-stabilized formulations lost all their transfection activity in 4 days. In these formulations cholesterol, not dioleoylphosphatidylethanolamine, was the helper lipid effective for sustaining high transfection activity in vivo. These new developments in formulation technology should enhance the potential for liposome-mediated gene therapy.
Assuntos
Cátions , DNA , Técnicas de Transferência de Genes , Lipossomos , Fosfolipídeos/química , Poliaminas/química , Polietilenoglicóis/química , Animais , Colesterol/química , Portadores de Fármacos , Feminino , Genes Reporter , Humanos , Luciferases/genética , Camundongos , Fosfatidiletanolaminas/química , Plasmídeos , Compostos de Amônio Quaternário/química , Fatores de Tempo , Células Tumorais CultivadasRESUMO
An immunoisolation membrane formed by incorporating a high water content polyvinyl alcohol (PVA) hydrogel into a microporous polyether sulfone (PES) filter has been investigated in this study. The PVA hydrogel is formed in situ within the filter pores via glutaraldehyde (GA) crosslinking under acidic conditions. The tortuous nature of the microporous filter pores securely anchors the embedded hydrogel to provide excellent structural integrity. The high void fraction of the PES filter support (>80%) and high water content of the PVA hydrogel (>85% water by weight) allow excellent solute transport rates, while an appropriate level of glutaraldehyde crosslinking supplies the required molecular size selectivity. In vitro permeability measurements made with solutes covering a wide range of molecular sizes demonstrate high transport rates for small nutrient molecules with rapidly diminishing permeabilities above a molecular weight of approximately 1,000 Dalton. Implantation experiments show that the membrane properties are not deleteriously affected by prolonged in vivo exposure or common sterilization techniques. Thus, this hybrid hydrogel/filter membrane system offers a promising approach to the immunoisolation of implanted cells.
Assuntos
Materiais Biocompatíveis , Géis , Membranas Artificiais , Filtros Microporos , Álcool de Polivinil , Animais , Transplante de Células , Masculino , Cavidade Peritoneal , Permeabilidade , Ratos , Ratos Sprague-Dawley , Esterilização , TemperaturaRESUMO
An in vivo tracer technique that uses radiolabeled insulin as the tracer molecule has been developed to assess the rate of chemical transport between the cell transplantation chamber of an implantable bioartificial device and the host's circulatory system. The device considered here employs site-directed neovascularization of a porous matrix to induce capillary growth adjacent to an immunoisolated cell implantation chamber. This device design is being investigated as a vehicle for therapeutic cell transplantation, with the advantages that it allows the cells to perform their therapeutic function without the danger of immune rejection and it avoids damaging contact of blood flow with artificial surfaces. A pharmacokinetic model of the mass transport between the implantation chamber, the vascularized matrix, and the body has been devised to allow proper analysis and understanding of the experimental tracer results. Experiments performed in this study have been principally directed at evaluation of the tracer model parameters, but results also provide a quantitative measure of the progression of capillary growth into a porous matrix. Measured plasma tracer levels demonstrate that chemical transport rates within the implanted device increase with the progression of matrix vascular ingrowth. Agreement between the fitted model curves and the corresponding measured concentrations at different levels of capillary ingrowth demonstrate that the model provides a realistic representation of the actual capillary-mediated transport phenomena occurring within the device.
Assuntos
Bioprótese , Transplante de Células/métodos , Inulina/farmacocinética , Animais , Transporte Biológico , Radioisótopos de Carbono , Transplante de Células/fisiologia , Masculino , Microesferas , Neovascularização Patológica , Polímeros , Ratos , Ratos Sprague-Dawley , Radioisótopos de EstrôncioRESUMO
The effect of beta 2-adrenoceptor agonists, salmeterol and salbutamol on thromboxane B2 release from human airway macrophages and peripheral blood monocytes has been examined. Salbutamol (0.1-100 microM) had no inhibitory effect on the release of thromboxane B2 from human airway macrophages. Salmeterol (0.1-100 microM) caused dose-dependent inhibition of thromboxane B2 release from human airway macrophages stimulated by either zymosan or calcium ionophore A23187. This inhibition was not blocked by propranolol (1 microM). The activity of adenylyl cyclase in homogenates of human airway macrophages was increased by NaF (10 mM) by 8.5-fold and salmeterol (100 microM) and isoprenaline (10 microM) by 1.6- and 1.4-fold, respectively. Isoprenaline alone was inhibited by propranolol (1 microM). Salmeterol caused a biphasic inhibition of peripheral blood monocyte thromboxane B2 release. The inhibition at low (10 nM) concentrations of salmeterol was blocked by propranolol and that at higher concentrations (100 microM) was unaffected. The long lipophilic tail of salmeterol had similar inhibitory effects on the airway macrophages to salmeterol itself, and on the peripheral blood monocytes its action resembled that of the highest concentrations of salmeterol used. It is concluded that salmeterol inhibits mediator release from human airway macrophages by a beta-adrenoceptor independent mechanism and from blood monocytes by both beta-adrenoceptor and non-beta-adrenoceptor mechanisms. The latter mechanism may be associated with the lipophilic properties of the salmeterol molecule.
Assuntos
Agonistas Adrenérgicos beta/farmacologia , Albuterol/análogos & derivados , Broncodilatadores/farmacologia , Macrófagos Alveolares/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Adenilil Ciclases/metabolismo , Albuterol/farmacologia , Análise de Variância , Líquido da Lavagem Broncoalveolar/citologia , Calcimicina/farmacologia , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Isoproterenol/farmacologia , Macrófagos Alveolares/metabolismo , Monócitos/metabolismo , Propranolol/farmacologia , Xinafoato de Salmeterol , Fluoreto de Sódio/farmacologia , Tromboxano B2/metabolismo , Zimosan/farmacologiaRESUMO
It has been generally assumed that release of antibiotic from methylmethacrylate occurs either from the surface, through pores in the matrix of the cement, or by diffusion through the matrix. In vitro and in vivo studies of the release of antibiotic from cement have produced variable and inconsistent results. In our laboratory, preliminary observations suggested that antibiotic is released from methylmethacrylate by flow through an interconnecting series of voids and cracks in the cement, rather than through diffusion after having been homogeneously distributed throughout the cement. Therefore, experiments were performed to answer the fundamental question of whether the matrix of methylmethacrylate bone cement is permeable to gentamicin. In vivo elution studies were performed on injection-molded rods of methylmethacrylate that had been loaded with two different amounts of gentamicin. The first group of rods contained 0.5 gram of gentamicin for each packet and the second, 1.5 grams for each packet. The rods were embedded subcutaneously in the subcostal region of sheep for three months. Bioassay of sections of the rods, using the tube-diffusion technique of Mitchison and Spicer, showed that the more highly loaded cement had released a significantly greater proportion of gentamicin. This occurred because the more highly loaded cement contained a greater number of defects that contained gentamicin (filled voids and interconnecting cracks). In vitro diffusion studies were also performed, using 0.8-millimeter-thick disks of methylmethacrylate that did not contain antibiotic. Test solutions of either gentamicin or methylene blue were placed in the inner compartments of diffusion chambers. The outer compartments contained tissue-culture medium 199, which was sampled monthly and assayed for gentamicin or methylene blue.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Cimentos Ósseos/análise , Gentamicinas/farmacocinética , Metilmetacrilatos/análise , Animais , Difusão , Técnicas In Vitro , Metilmetacrilato , Microscopia Eletrônica de Varredura , Permeabilidade , Ovinos , EspectrofotometriaRESUMO
Severe microbial keratitis developed in a 74-year-old women receiving long-term corticosteroids. Corneal smears revealed slender, fusiform gram-negative bacilli, but the lesion continued to worsen despite intensive antibiotic treatment. After several days, Capnocytophaga sputigena was identified on culture. Specific antimicrobial therapy was instituted, supplemented with corneal cryotherapy. There was gradual clinical improvement. However, a sterile corneal melt led to the late loss of the eye. Although Capnocytophaga are gingival organisms and usually implicated as opportunists in severely ill, neutropenic patients with oral ulcerations, our patient was edentulous and without systemic immunosuppression. An increased awareness of Capnocytophaga is justified because of their widespread antibiotic resistance, capnophilic cultural requirements, and unusual microscopic and cultural morphology.
Assuntos
Infecções Bacterianas , Tolerância Imunológica , Ceratite/etiologia , Idoso , Capnocytophaga/isolamento & purificação , Dentição , Enucleação Ocular , Feminino , Humanos , Ceratite/microbiologia , Ceratite/cirurgiaRESUMO
Bleeding from cancellous bone causes lamination within bone cement and at its prosthetic interfaces, and weakens the fixation of joint replacements. We examined the effects of anaesthesia and blood pressure on bleeding in human cancellous bone, and investigated the local response to freezing saline, 1:200,000 adrenaline and hydrogen peroxide. Spinal anaesthesia reduced cancellous bleeding by an average of 44%, local freezing saline by 24%. Saline at room temperature, adrenaline solution and hydrogen peroxide each reduced it by 14%. The effects of spinal anaesthesia and of freezing saline were additive: used together they reduced bleeding by 56%. The reduction of blood contamination of cement and its interfaces should contribute to better prosthetic fixation.