Enhanced bone tissue regeneration with hydrogel-based scaffolds by embedding parathyroid hormone in mesoporous bioactive glass.

OBJECTIVES: To evaluate hydrogel-based scaffolds embedded with parathyroid hormone (PTH)-loaded mesoporous bioactive glass (MBG) on the enhancement of bone tissue regeneration in vitro. MATERIALS AND METHODS: MBG was produced via sol-gel technique followed by PTH solution imbibition. PTH-loaded MBG was blended into the hydrogels and submitted to a lyophilisation process associated with a chemical crosslinking reaction to the production of the scaffolds. Characterisation of the MBG and PTH-loaded MBG scaffolds, including the scanning electron microscope (SEM) connected with an X-ray detector (EDX), Fourier transform infrared (FTIR), compression strength, rheological measurements, swelling and degradation rates, and PTH release analysis, were performed. Also, bioactivity using simulated-body fluid (SBF), biocompatibility (MTT), and osteogenic differentiation analyses (von Kossa and Alizarin Red stainings, and µ-computed tomography, µCT) of the scaffolds were carried out. RESULTS: SEM images demonstrated MBG particles dispersed into the hydrogel-based scaffold structure, which was homogeneously porous and well interconnected. EDX and FTIR revealed large amounts of carbon, oxygen, sodium, and silica in the scaffold composition. Bioactivity experiments revealed changes on sample surfaces over the analysed period, indicating the formation of carbonated hydroxyapatite; however, the chemical composition remained stable. PTH-loaded hydrogel-based scaffolds were biocompatible for stem cells from human-exfoliated deciduous teeth (SHED). A high quantity of calcium deposits on the extracellular matrix of SHED was found for PTH-loaded hydrogel-based scaffolds. µCT images showed MBG particles dispersed into the scaffolds' structure, and a porous, lamellar, and interconnected hydrogel architecture. CONCLUSIONS: PTH-loaded hydrogel-based scaffolds demonstrated consistent morphology and physicochemical properties for bone tissue regeneration, as well as bioactivity, biocompatibility, and osteoinductivity in vitro. Thus, the scaffolds presented here are recommended for future studies on 3D printing. CLINICAL RELEVANCE: Bone tissue regeneration is still a challenge for several approaches to oral and maxillofacial surgeries, though tissue engineering applying SHED, scaffolds, and osteoinductive mediators might help to overcome this clinical issue.

Phenotype changes of oral epithelial stem cells after in vitro culture.

The aim of our study was to isolate populations of keratinocyte stem cells based on the expression of cell surface markers and to investigate whether the culture could affect their phenotype. keratinocytes from human oral mucosa were sorted based on the expression of the epithelial stem cell markers p75NTR and CD71. We also examined the co-expression of other epithelial stem markers such as integrins ß1 and α6 and their stem cell-like proprieties in in vitro assays. Three passages after being sorted by MACS, more than 93% of the p75NTR+ve cells lost the expression of p75NTR, while 5.46% of the p75NTR-ve gained it. Within the small population of the p75NTR+ve cells, 88% co-expressed other epithelial stem cell markers such as integrins ß1 and α6, while only 28% of p75NTR-ve cells co-expressed these markers. These results were confirmed by sorting cells by FACS. Additionally, when double staining was used for sorting cells, 99% of the p75NTR+veCD71-ve and 33% of the p75NTR-veCD71+ve cells expressed both integrins, but just one week after culture, only 1.74% of the p75NTR+veCD71-ve cells still expressed p75NTR and only 0.32% still expressed CD71. Similar results were obtained when co-culturing p75NTR+ve and p75NTR-ve populations before analysis. Our results suggest that phenotype changes may be part of an intrinsic cellular mechanism to conserve levels of protein expression as they may found in the human body. In addition, in vitro culture may not offer ideal conditions for epithelial stem cell maintenance due to phenotype changes under standard culture conditions.

Phenotype changes of oral epithelial stem cells after in vitro culture

Abstract The aim of our study was to isolate populations of keratinocyte stem cells based on the expression of cell surface markers and to investigate whether the culture could affect their phenotype. keratinocytes from human oral mucosa were sorted based on the expression of the epithelial stem cell markers p75NTR and CD71. We also examined the co-expression of other epithelial stem markers such as integrins β1 and α6 and their stem cell-like proprieties in in vitro assays. Three passages after being sorted by MACS, more than 93% of the p75NTR+ve cells lost the expression of p75NTR, while 5.46% of the p75NTR-ve gained it. Within the small population of the p75NTR+ve cells, 88% co-expressed other epithelial stem cell markers such as integrins β1 and α6, while only 28% of p75NTR-ve cells co-expressed these markers. These results were confirmed by sorting cells by FACS. Additionally, when double staining was used for sorting cells, 99% of the p75NTR+veCD71-ve and 33% of the p75NTR-veCD71+ve cells expressed both integrins, but just one week after culture, only 1.74% of the p75NTR+veCD71-ve cells still expressed p75NTR and only 0.32% still expressed CD71. Similar results were obtained when co-culturing p75NTR+ve and p75NTR-ve populations before analysis. Our results suggest that phenotype changes may be part of an intrinsic cellular mechanism to conserve levels of protein expression as they may found in the human body. In addition, in vitro culture may not offer ideal conditions for epithelial stem cell maintenance due to phenotype changes under standard culture conditions.

Outpatient Autologous Stem Cell Transplantation for Patients With Myeloma.

BACKGROUND: High-dose melphalan with autologous stem cell support improves survival for patients with myeloma. For selected patients, we have been using a protocol of short hospitalization, discharging patients to home with careful outpatient monitoring in the office, which we hypothesized would reduce complications and utilization of inpatient beds. METHODS: We reviewed 301 initial autologous transplants for myeloma, categorized as brief stay (≤ 4 days, 82 patients) or prolonged stay (≥ 5 days, 219 patients). Selection for a brief stay was determined by clinical characteristics, availability of caregivers at home, distance from our medical center, and patient preference. RESULTS: Within the brief stay population, 67% required readmission before day + 100, but this group still had fewer cumulative hospital days (9 vs. 18, P < .0001). There were fewer documented infections among brief stay patients (22% vs. 46% P < .001) and fewer admissions to intensive care units (0% vs. 5.9%, P = .02). The groups had similar rates of bleeding (1.2% vs. 1.4% P = 1.0) and thrombosis (3.7% vs. 4.6% P = 1.0). No patients in the brief stay group died within 100 days, compared with mortality of 1.8% (P = .6) in the prolonged stay group. CONCLUSION: Carefully selected patients receiving an autologous stem cell transplant for treatment of myeloma can be managed with a brief initial hospitalization and outpatient follow-up, with low morbidity and mortality.

Health and quality of life in adults with Noonan syndrome.

OBJECTIVE: To obtain information on health and quality of life in adults with Noonan syndrome. STUDY DESIGN: From a cohort of 144 children with the diagnosis of Noonan syndrome whose height data had been published 23 years ago, 103 pediatric files providing adequate data were identified. Participants were sent questionnaires and asked to provide saliva for DNA analysis and to return for physical examination. RESULTS: Ten of 103 individuals had died, 3 of them suddenly (standardized mortality ratio, 3.00; 95% CI, 1.44-5.52). Eighty-one individuals could be contacted by mail, with a positive response from 45. Genotyping in 36 of 45 participants revealed characteristic mutations in 61%. Median age at follow-up was 42.8 years. Mean adult heights were 169.2 cm (men) and 154.4 cm (women). In comparison with the general population, participants had lower educational status and lived more frequently without any partner. According to the response to the Short Form-36 questionnaire, quality of life was not impaired. CONCLUSIONS: Individuals with Noonan syndrome have higher mortality, lower education, and rarely partnership. Quality of life according to self-reported Short Form-36 was good. Men grew taller than previously reported from this cohort.

Defecaçäo induzida por esquema múltiplo de reforçamento / Schedule-induced defecation under multiple schedule of reinforcement

O objetivo do presente experimento foi o de verificar a relaçäo entre esquema e defecçäo induzida por esquemas de reforçamento. Através de esquema múltiplo, o controle exercido entre sessöes, previamente relatado, foi verificado intra-sessöes. Dois ratos albinos foram utilizados como sujeitos. Uma caixa operante para pequenos roedores serviu como caixa experimental. O experimento consistiu de 20 sessöes de 30 minutos, nas quais segmentos de 5 minutos de CRF eram intercalados com segmentos de 5 minutos de Fl-32 segundos. Os resultados demonstraram a ocorrência sistemática de defecaçäo durante os segmentos de Fl-32 segundos e sua ausência durante os segmentos de CRF. Os resultados confirmam o controle exercido por esquemas temporais sobre defecaçäo, tanto inter quanto intra-sessäo

Estudo de algumas variáveis de procedimento na defecaçäo induzida por esquemas de reforçamento / Study of some procedural variables on schedull induced defection

Defecaçäo induzida por esquemas de reforçamento foi estudada através de um experimento de duas fases, utilizando-se ratos como sujeitos. Uma vez que reforçamento por água e por comida produzem diferentes padröes de defecaçäo induzida, na primeira fase do experimento foi utilizado um reforçador, comida em pó, que requer uma topografia consumatória de lambedura (como em água), mas é uma comida. Padröes de defecaçäo relacionados a comida foram obtidos, sugerindo que as diferenças produzidas por comida e água säo relacionadas a natureza do reforçador ao invés da topografia da resposta que o consome. A segunda fase do experimento foi dirigida ao fato de que embora os ratos defequem sob esquemas de FI-32 seg e näo sob esquemas de CRF, os parâmetros temporais que distinguem os esquemas säo obscurecidos pelas diferenças nas quantidades de reforçamento apresentadas. O tamanho de cada apresentaçäo de reforçamento foi aumentado durante sessöes de FI-32 seg, de maneira que o total de reforçamento recebido durante cada sessäo aproximou-se do total recebido durante cada sessäo padräo de CRF. Os ratos defecaram sob os esquemas de intervalo, como antes, sugerindo que os parâmetros temporais do esquema, e näo as quantidades de reforçamento, säo as variáveis créticas em defecaçäo induzida por esquemas de reforçamento

Estudo de algumas variaveis de procedimento na defecacao induzida por esquemas de reforcamento

Defecacao induzida por esquemas de reforcamento foi estudada atraves de um experimento de duas fases, utilizando-se ratos como sujeitos. Uma vez que reforcamento por agua e por comida produzem diferentes padroes de defecacao induzida, na primeira fase do experimento foi utilizado um reforcador, comida em po, que requer uma topografia consumatoria de lambedura (como em agua), mas e uma comida. Padroes de defecacao relacionados a comida foram obtidos, sugerindo que as diferencas produzidas por comida e agua sao relacionadas a natureza do reforcador ao inves da topografia da resposta que o consome. A segunda fase do experimento foi dirigida ao fato de que embora os ratos defequem sob esquemas de FI-32 seg e nao sob esquemas de CRF, os parametros temporais que distinguem os esquemas sao obscurecidos pelas diferencas nas quantidades de reforcamento apresentadas. O tamanho de cada apresentacao de reforcamento foi aumentado durante sessoes de FI-32 seg, de maneira que o total de reforcamento recebido durante cada sessao aproximou-se do total recebido durante cada sessao padrao de CRF. Os ratos defecaram sob os esquemas de intervalo, como antes, sugerindo que os parametros temporais do esquema, e nao as quantidades de reforcamento, sao as variaveis criticas em defecacao induzida por esquemas de reforcamento.