374 research outputs found
Bone mineral density and risk of heart failure in older adults: The Cardiovascular Health Study
Background
Despite increasing evidence of a common link between bone and heart health, the relationship between bone mineral density (
BMD
) and heart failure (
HF
) risk remains insufficiently studied.
Methods and Results
We investigated whether
BMD
measured by dual‐energy x‐ray absorptiometry was associated with incident
HF
in an older cohort. Cox models were stratified by sex and interactions of
BMD
with race assessed.
BMD
was examined at the total hip and femoral neck separately, both continuously and by World Health Organization categories. Of 1250 participants, 442 (55% women) developed
HF
during the median follow‐up of 10.5 years. In both black and nonblack women, neither total hip nor femoral neck
BMD
was significantly associated with
HF
; there was no significant interaction by race. In black and nonblack men, total hip, but not femoral neck,
BMD
was significantly associated with
HF
, with evidence of an interaction by race. In nonblack men, lower total hip
BMD
was associated with higher
HF
risk (hazard ratio, 1.13 [95% CI, 1.01–1.26] per 0.1 g/cm
2
decrement), whereas in black men, lower total hip
BMD
was associated with lower
HF
risk (hazard ratio, 0.74 [95% CI, 0.59–0.94]). There were no black men with total hip osteoporosis. Among nonblack men, total hip osteoporosis was associated with higher
HF
risk (hazard ratio, 2.83 [95% CI, 1.39–5.74]) compared with normal
BMD
.
Conclusions
Among older adults, lower total hip
BMD
was associated with higher
HF
risk in nonblack men but lower risk in black men, with no evidence of an association in women. Further research is needed to replicate these findings and to study potential underlying pathways.
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Investigation of bone resorption within a cortical basic multicellular unit using a lattice-based computational model
In this paper we develop a lattice-based computational model focused on bone
resorption by osteoclasts in a single cortical basic multicellular unit (BMU).
Our model takes into account the interaction of osteoclasts with the bone
matrix, the interaction of osteoclasts with each other, the generation of
osteoclasts from a growing blood vessel, and the renewal of osteoclast nuclei
by cell fusion. All these features are shown to strongly influence the
geometrical properties of the developing resorption cavity including its size,
shape and progression rate, and are also shown to influence the distribution,
resorption pattern and trajectories of individual osteoclasts within the BMU.
We demonstrate that for certain parameter combinations, resorption cavity
shapes can be recovered from the computational model that closely resemble
resorption cavity shapes observed from microCT imaging of human cortical bone.Comment: 17 pages, 11 figures, 1 table. Revised version: paper entirely
rewritten for a more biology-oriented readership. Technical points of model
description now in Appendix. Addition of two new figures (Fig. 5 and Fig. 9)
and removal of former Fig.
Intragastric gastric band migration: erosion: an analysis of multicenter experience on 177 patients
BACKGROUND:
Laparoscopic adjustable gastric banding (LAGB) has proven to be a safe and effective surgical treatment for morbid obesity. It can be a simple, fast, reversible, anatomy-preserving procedure. Despite these advantages, its long-term efficacy came into question by the occurrence of complications such as intragastric band migration. Consistent information regarding this complication is still lacking. Treatment for migration is still being debated as well. Most of the inconsistencies of these data stem from the very low number of patients reported in single-center experiences or case reports. Lack of multicenter experience is evident. The aim of this study was to perform a retrospective analysis of data on intragastric migration in a large multicenter cohort of patients who underwent LAGB.
METHODS:
A retrospective multicenter study on LAGB patients was performed. Data had been entered into a prospective database of the Italian Group for LapBand(®) (GILB) since January 1997. Pars flaccida and perigastric positioning were considered along with different kinds of gastric bands by the same manufacturer. Time of diagnosis, mean body mass index (BMI), presentation symptoms, and conservative and surgical therapy of intragastric migration were considered.
RESULTS:
From January 1997 to December 2009, a total of 6,839 patients underwent LAGB and their data were recorded [5,660 females, 1,179 males; mean age 38.5 ± 18.2 years (range 21-62 years); mean BMI = 46.7 ± 7.7 kg/m(2) (range 37.3-68.3); excess weight (EW) 61.8 ± 25.4 kg (range 36-130); %EW 91.1 ± 32.4 % (range 21-112 %)]. A total of 177 of 6,839 (2.5 %) intragastric erosions were observed. According to the postoperative time of follow-up, the diagnosis of intragastric migration was made in 74 (41.8 %), 14 (7.9 %), 38 (21.4 %), 40 (22.6 %), 6 (3.4 %), and 4 (2.2 %) banded patients at 6-12, 24, 36, 48, 60, and 72 months after banding, respectively. Most of intragastric band migration during the first 2 years occurred in bands with no or a few milliliters of filling. In patients with late erosion, the bands were adjusted several times; no band was overfilled but one was filled to the maximum or submaximum with a maximum of two adjustments. Erosions diagnosed during the first 24 months were related to the experience of the surgical staff, while late erosions were not.
CONCLUSIONS:
Intragastric band migration or band erosion is a rare, disturbing, and usually not life-threatening complication of gastric banding. Its pathogenesis is probably linked to different mechanisms in early (technical failure in retrogastric passage) or late (band management) presentation. It is usually asymptomatic and there is no pathognomonic presentation. A wide range of therapeutic options are available, from simple endoscopic or laparoscopic removal to early or late band replacement or other bariatric procedure. More experience and more studies are needed to lower its presentation rate and definitively clarify its pathogenesis to address the right therapeutic option
Materials in particulate form for tissue engineering. 2 Applications in bone
Materials in particulate form have been the subjects of intensive research in view of their use as
drug delivery systems. While within this application there are still issues to be addressed, these
systems are now being regarded as having a great potential for tissue engineering applications.
Bone repair is a very demanding task, due to the specific characteristics of skeletal tissues, and the
design of scaffolds for bone tissue engineering presents several difficulties. Materials in particulate
form are now seen as a means of achieving higher control over parameters such as porosity, pore
size, surface area and the mechanical properties of the scaffold. These materials also have the
potential to incorporate biologically active molecules for release and to serve as carriers for cells. It
is believed that the combination of these features would create a more efficient approach towards
regeneration. This review focuses on the application ofmaterials in particulate formfor bone tissue
engineering. A brief overview of bone biology and the healing process is also provided in order to
place the application in its broader context. An original compilation of molecules with a documented
role in bone tissue biology is listed, as they have the potential to be used in bone tissue engineering
strategies. To sum up this review, examples of works addressing the above aspects are presented
Deciphering Earth's Movements: Unveiling Subsidence and Displacement in Capo Colonna Through SAR and CGPS
This study investigates the subsidence phenomenon in the Capo Colonna area (Calabria, southern Italy) using Synthetic Aperture Radar (SAR) data from C and X bands, and Continuous Global Positioning System (CGPS) measurements collected between 2003 and 2018. Persistent Scatterer Pair Differential Interferometry Synthetic Aperture Radar (PSP-DIFSAR) and Small Baseline Subset (SBAS) techniques were employed to produce detailed deformation maps. With ascending and descending datasets from various satellites, along with acquisition parameters such as incidence and heading angles, the Line of Sight (LOS) measurements were decomposed into vertical and east-west displacement components. This provided a comprehensive understanding of the displacement rates in the Capo Colonna peninsula, revealing significant subsidence patterns, particularly in the promontory. Varied deformation rates were observed across different sectors, with higher rates in the peninsula than in Crotone's hinterland and urban areas. The complementary comparison between SAR and CGPS data offered critical insights into the region's geodynamic behavior, enhancing risk assessment and management strategies to preserve its geological and archaeological heritage
Bone fragility and decline in stem cells in prematurely aging DNA repair deficient trichothiodystrophy mice
Trichothiodystrophy (TTD) is a rare, autosomal recessive nucleotide excision repair (NER) disorder caused by mutations in components of the dual functional NER/basal transcription factor TFIIH. TTD mice, carrying a patient-based point mutation in the Xpd gene, strikingly resemble many features of the human syndrome and exhibit signs of premature aging. To examine to which extent TTD mice resemble the normal process of aging, we thoroughly investigated the bone phenotype. Here, we show that female TTD mice exhibit accelerated bone aging from 39 weeks onwards as well as lack of periosteal apposition leading to reduced bone strength. Before 39 weeks have passed, bones of wild-type and TTD mice are identical excluding a developmental defect. Albeit that bone formation is decreased, osteoblasts in TTD mice retain bone-forming capacity as in vivo PTH treatment leads to increased cortical thickness. In vitro bone marrow cell cultures showed that TTD osteoprogenitors retain the capacity to differentiate into osteoblasts. However, after 13 weeks of age TTD females show decreased bone nodule formation. No increase in bone resorption or the number of osteoclasts was detected. In conclusion, TTD mice show premature bone aging, which is preceded by a decrease in mesenchymal stem cells/osteoprogenitors and a change in systemic factors, identifying DNA damage and repair as key determinants for bone fragility by influencing osteogenesis and bone metabolism
UFT/leucovorin and oxaliplatin alternated with UFT/leucovorin and irinotecan in metastatic colorectal cancer
A total of 41 metastatic colorectal cancer (CRC) patients received tegafur/uracil (UFT)+leucovorin (LV)+oxaliplatin alternated with UFT/LV+irinotecan. The overall response rate was 58.5% (95% confidence interval, 42.2-73.3%), and the median progression-free survival was 8.8 months. There were no grade 4 toxicities; 12 patients (29%) experienced grade 3 diarrhoea. There were no cases of hand-foot syndrome. This alternating regimen seems to be effective and well tolerated in the first-line treatment of patients with metastatic CRC
Neuropeptide Y, substance P, and human bone morphogenetic protein 2 stimulate human osteoblast osteogenic activity by enhancing gap junction intercellular communication
Magnetic resonance imaging: Is there a role in clinical management for acute ischemic colitis?
AIM: To validate the utility of magnetic resonance imaging (MRI) for the clinical management of acute ischemic colitis (IC).
METHODS:
This is a magnetic resonance (MR) prospective evaluation of 7 patients who were proved to have acute IC on the basis of clinical, endoscopic and computed tomography (CT) findings and who were imaged in our institution between February 2011 and July 2012. The mean age of the patients was 72.28 years. Abdominal CTs were obtained using a 64-detector row configuration for all patients with un-enhanced and contrast-enhanced scans, in the late arterial phase (start delay 45-50 s) and in the portal venous phase (start delay 70-80 s). The MR examinations were performed using a 1.5T superconducting magnet, using Fast Imaging Employing Steady State Acquisition and T2-weighted fast-recovery fast-spin echo sequences in axial and coronal plane. CT and MRI examinations were analysed for the presence of colonic abnormalities and associated findings.
RESULTS:
Segmental involvement was seen in 6 patients (85.71%), with a mean length of involvement of 412 mm (range 145.5-1000 mm). Wall thickness varied between 6 mm and 17.5 mm (mean 10.52 mm) upon CT examinations and from 5 to 15 mm (mean 8.8 mm) upon MR examinations. The MRI appearance of the colonic wall varied over the time: Type I appearance with a 3 layer sandwich sign was seen in 5 out of 12 examinations (41.66%), patients underwent MR within a mean of 36 h (ranging from 1 to 54 h) after the CT examination. Type II and III appearance with a 2 layer sign, was seen in 4 examinations (33.33%), patients underwent MR within a mean of 420.5 h (ranging from 121 to 720 h) after the CT examination. In the remaining three MRI examinations, performed within a mean of 410 h (ranging from 99.5 to 720 h) the colonic wall appeared normal.
CONCLUSION:
MRI, only using precontrast images, may be used as a substitute for invasive procedures in diagnosis and follow-up of acute IC
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