Receptor activator of NF-κB ligand-dependent expression of caveolin-1 in osteoclast precursors, and high dependency of osteoclastogenesis on exogenous lipoprotein

Although extensive studies have done much to clarify the molecular mechanisms of osteoclastogenesis during the last ten years, there may still be unknown molecules associated with osteoclast differentiation. Thus, we used fluorescent differential display to screen for genes whose expression is induced by receptor activator of NF-κB ligand (RANKL), a crucial molecule for osteoclast formation. We identified caveolin-1 (Cav-1) as a RANKL-induced gene. Cav-1 is a major structural protein of caveolae and lipid rafts, cholesterol-enriched microdomains in the plasma membrane (PM). The RANKL-induced Cav-1 was immediately conveyed to lipid rafts. Conversely, expression of flotillin-1 (Flot-1), another scaffolding protein of lipid rafts, was reduced during osteoclastogenesis, indicating conversion of Flot-1-predominant rafts into Cav-1-enriched rafts. However, in vitro osteoclastogenesis of precursor cells from Cav-1-null mice was comparable to that of wild-type mice, while Cav-2 expression in the knockout osteoclasts was maintained. Conversely, Cav-2 gene silencing in Cav-1-null osteoclast precursors using siRNA for Cav-2 increased osteoclast formation, suggesting that the Cav-1/Cav-2 complex may act as a negative regulator for osteoclastogenesis. On the other hand, destruction of lipid rafts by removal of cholesterol from the PM by methyl-ß-cyclodextrin (MCD) treatment caused disordered signal transductions for osteoclastogenesis, such as hyperactivation of Erk1/2 and insensitivity of Akt to RANKL stimulus. The abnormal signaling was reproduced by deleting exogenous lipoproteins from the culture medium, which also resulted in reduced osteoclast formation. In addition, the deletion caused delayed expression of nuclear factor of activated T cells c1 (NFATc1), and depressed its activation in the cytosol and inhibited its translocation into nuclei. Simultaneously, the deletion reduced the level of FcRγ, a trigger protein for initiating the calcium signaling needed to activate NFATc1, and decreased Cav-1 in lipid rafts. These findings indicate that the molecular mechanisms of osteoclastogenesis are highly dependent on extracellular lipoprotein and the integrity of lipid rafts, and suggest possible involvement of cholesterol.     

Prediction of fracture risk in men: a cohort study

FRAX is a tool that identifies individuals with high fracture risk who will benefit from pharmacological treatment of osteoporosis. However, a majority of fractures among elderly occur in people without osteoporosis and most occur after a fall. Our aim was to accurately identify men with a high future risk of fracture, independent of cause. In the population‐based Uppsala Longitudinal Study of Adult Men (ULSAM) and using survival analysis we studied different models' prognostic values (R²) for any fracture and hip fracture within 10 years from age 50 (n = 2322), 60 (n = 1852), 71 (n = 1221), and 82 (n = 526) years. During the total follow‐up period from age 50 years, 897 fractures occurred in 585 individuals. Of these, 281 were hip fractures occurring in 189 individuals. The rates of any fracture were 5.7/1000 person‐years at risk from age 50 years and 25.9/1000 person‐years at risk from age 82 years. Corresponding hip fractures rates were 2.9 and 11.7/1000 person‐years at risk. The FRAX model included all variables in FRAX except bone mineral density. The full model combining FRAX variables, comorbidity, medications, and behavioral factors explained 25% to 45% of all fractures and 80% to 92% of hip fractures, depending on age. The corresponding prognostic values of the FRAX model were 7% to 17% for all fractures and 41% to 60% for hip fractures. Net reclassification improvement (NRI) comparing the full model with the FRAX model ranged between 40% and 53% for any fracture and between 40% and 87% for hip fracture. Within the highest quintile of predicted fracture risk with the full model, one‐third of the men will have a fracture within 10 years after age 71 years and two‐thirds after age 82 years. We conclude that the addition of comorbidity, medication, and behavioral factors to the clinical components of FRAX can substantially improve the ability to identify men at high risk of fracture, especially hip fracture. © 2012 American Society for Bone and Mineral Research.     

The Use of Stereotactic Excisional Biopsy in the Management of Invasive Breast Cancer

Stereotactic breast biopsy techniques minimize the surgical trauma associated with conventional wire-guided open breast biopsy for non-palpable breast lesions (NPBLs). Advanced breast biopsy instrumentation (ABBI) allows for a 2-cm core of breast tissue to be excised under stereotactic guidance in an outpatient setting. We report our initial experience with ABBI. Hospital charts from 89 ABBI procedures between 10/1996 and 07/2002 were retrospectively reviewed for patient characteristics, ABBI parameters, radiographic appearance, pathology, complications, and clinical follow-up. Data are presented as percentage/median (range). Median age was 59 years (range: 39–80 years), mammographic lesions were classified as calcifications 49% (44/89), soft tissue 39% (35/89), or mixed 11% (10/89). Median radiographic size was 7 mm (1–60 mm). Final pathology revealed ductal carcinoma in situ (DCIS) in 7% (6/89) and invasive cancer in 22% (20/89). Microscopically clear margins were obtained in 55% (11/20) of patients with invasive cancer. Of these, 82% (9/11) chose not to undergo further local surgical therapy. Eight patients remain disease free at 56 months (range: 41–95 months) follow-up. The ninth patient was deceased at 6 months from an unrelated cause. The overall complication rate was 3% (3/89). A definitive diagnosis was obtained in 100% of malignant and 87% of benign cases. Median waiting time was 19 days (range: 0–90 days). Our experience demonstrates that ABBI is an effective diagnostic tool for NPBLs. It is associated with minimal complications, and provides negative margins in over half of malignant cases. In selected patients with invasive cancer and negative margins, ABBI may obviate the need for further local surgical treatment. ABBI merits additional investigation as a therapeutic modality for early breast cancer.     

Evolution of health-related quality of life two to seven years after retropubic radical prostatectomy: evaluation by UCLA prostate cancer index

To determine changes in health-related quality of life (HRQOL) in patients treated with retropubic radical prostatectomy (RP) between two and seven years after surgery. A questionnaire from the University of California Los Angeles Prostate Index was sent to 142 patients previously treated with retropubic RP as mono-therapy for clinically localized prostate cancer. Patients were divided into five groups according to time from surgery. Demographics, clinical and pathological characteristics of patients were compared between these groups. Correlation coefficients controlled for age at the time of questionnaire between HRQOL scores and time from RP were assessed. A total of 105 patients (74%) returned the questionnaire. The mean time from surgery was 48 months (range 25–84). Demographics, clinical and pathological characteristics of patients were not statistically different between time groups. Several recoding items were found to decrease significantly with the time from RP including physical functioning, role limitations due to physical health problem, vitality, and general health. In contrary, urinary, bowel and sexual scores were not significantly correlated to time from RP. Although sexual, urinary and bowel scores seem to remain stable from 2 to 7 years following RP, general health appears to significantly deteriorate with time after RP, independent of the patient’s age at the time of the questionnaire.     

The aluminum content of bone increases with age, but is not higher in hip fracture cases with and without dementia compared to controls

Aluminum is considered a potentially toxic metal, and aluminum poisoning may lead to three types of disorders: aluminum-induced bone disease, microcytic anemia and encephalopathy. This is well known in patients with chronic renal failure, but since healthy subjects with normal renal function retain 4% of the aluminum consumed, they are also at risk of long-term low-grade aluminum intoxication. Included in this study were a total of 172 patients (age range 16–98 years) with the aim of examining whether aluminum accumulates in bone with increasing age. Additionally, we aimed to investigate whether the aluminum content of bone differs between controls and hip fracture cases with and without dementia, in particular in those with Alzheimers disease. During operations for all cases, bone biopsies were taken with an aluminum-free instrument from the trabecular bone. The samples were measured for their content of aluminum using an inductively coupled mass spectrometer. We found an exponential increase in aluminum content of bone with age. The average aluminum values, adjusted for age, were similar in men and women (P=0.46). No significant differences in sex- and age-adjusted mean aluminum values between the controls and the hip fracture cases with (P=0.72) and without (P=0.33) dementia could be detected. The average aluminum concentration among cases with Alzheimers disease was also similar to the values of hip fracture patients with other types of dementia (P=0.47). Odds ratios of hip fracture for each quartile of aluminum content in bone were also estimated to detect non-linear effects, but we did not find any statistically significant association remaining after age and sex adjustment. Thus, our results indicate that we accumulate aluminum in bone over our life span, but this does not seem to be of major pathogenetic significance for the occurrence of hip fracture or dementia.     

Traumatic hip dislocation in childhood

Traumatic dislocation of the hip in childhood is uncommon and can be a consequence of minor trauma. The authors report a series of 35 dislocations in skeletally immature patients. Most were isolated posterior dislocations without acetabular lesions. In 75% of cases, reduction of the dislocation was easy. Nine children required surgery to remove interposed joint capsule and/or osteochondral fragments to achieve anatomic reduction. Outcomes were generally good, except in one patient in whom a displaced fracture of the femoral physis was followed by total head avascular necrosis. One case of partial necrosis had a satisfactory outcome. Epiphyseal necrosis, though uncommon, appeared to be inconsistent to prevent and hard to predict. Bone scan seems to be more effective than MRI for the detection of necrosis.     

Changes in core temperature associated with lower extremity tourniquet--the influence of ambient temperature and warming equipments

BACKGROUND: We investigated changes in core temperature associated with lower extremity tourniquet (TQ) under two different ambient temperatures (1) and two different warming equipments (2) under general anesthesia combined with lumbar epidural anesthesia. METHODS: (1) The values of core temperature at ambient temperature of either 22 degrees C (n = 15) or 20 degrees C (n=15) were recorded after induction of anesthesia, at start of TQ application, at the termination of TQ application, and 14 minute after TQ release. (2) The values of core temperature using either air-forced warming or active heated i.v. at ambient temperature 20 degrees C were recorded at four points as mentioned above. RESULTS: (1) Changes in core temperature were not observed during TQ application at ambient temperature both 20 degrees C and 22 degrees C. Core temperatures in both groups decreased significantly after TQ release, and core temperatures at termination of TQ application and after TQ release at ambient temperature 20 degrees C were significantly lower than those at ambient temperature 22 degrees C. (2) Significant increases in core temperatures using two different warming equipments were observed at termination of TQ application and after TQ release at ambient temperature 20 degrees C. Core temperatures using air-forced warming were maintained during the investigation, though significant decrease in core temperature using active heated i.v. was recorded after TQ release. CONCLUSIONS: Air-forced warming maintains core temperature efficiently associated with lower extremity tourniquet.     

Shifting risk-stratified early prostate cancer detection to a primary healthcare setting

Objective

To evaluate the feasibility of multivariable risk stratification for early prostate cancer (PCa) detection in a primary healthcare diagnostic facility with regard to its effects on the referral rate and subsequent PCa diagnoses compared to a PSA threshold of 3.0 ng/mL as the current referral indicator.

Patients and Methods

In 2014, the Erasmus MC Cancer Institute and the primary healthcare diagnostic facility STAR-SHL (located in Rotterdam city centre) initiated this observational study, in which general practitioners (GPs) could refer men who wished to undergo PCa screening to STAR-SHL for consultation by specially trained personnel. Referral recommendations to secondary healthcare were based on the outcome of application of the Rotterdam Prostate Cancer Risk Calculator (RPCRC) and were compared to the current Dutch GPs' PSA referral threshold of 3.0 ng/mL. For data collection on PCa diagnoses, the study cohort was linked to the Dutch nationwide pathology databank (PALGA).

Results

Between January 2014 and February 2021, 507 men were referred for consultation and in 495 men prostate-specific antigen (PSA) was tested. The median (interquartile range) follow-up from consultation to PALGA linkage was 43 (25–65) months. In total, 279 men (56%) had a PSA level ≥3.0 ng/mL, of whom 68% (95% confidence interval [95% CI] 63–74) were considered at low risk according to the RPCRC. Within 1 year after consultation, one of these men (0.52%; 95% CI 0.092–2.9) was diagnosed with clinically significant (cs)PCa (i.e., International Society of Urological Pathology Grade Group ≥2). Thereafter, another four (2.1%; 95% CI 0.82–5.3) low-risk men were diagnosed with csPCa. Of the high-risk men who were biopsied within 1 year after consultation (n = 61), 77% (95% CI 65–86) were diagnosed with PCa and 49% (95% CI 37–61) with csPCa.

Conclusion

In a primary healthcare diagnostic facility, the RPCRC could reduce up to 68% of referrals to secondary healthcare, as compared to a PSA referral threshold of 3.0 ng/mL. Deploying the RPCRC in this setting resulted in a high csPCa detection rate in those men biopsied. This strategy can be considered safe since the observational data showed low proportions of csPCa among men at low risk.