Transjugular liver biopsy: a review of 461 biopsies

Transjugular liver biopsy was performed in a large series of patients for whom routine percutaneous biopsy was contraindicated; most of the patients had severe liver disease associated with coagulopathies or massive ascites. Of the 461 biopsies performed over a 7-year period, adequate specimens for histologic diagnosis were obtained in 425; in 14 (3.3%), the biopsy provided a false-negative result. Minor complications such as neck pain, hematoma at the puncture site, or pyrexia occurred in 79 patients (17.1%). Serious complications were encountered in six patients (1.3%) (two with cardiac arrhythmias; four with intraperitoneal hemorrhage following capsular perforation), with an overall mortality rate for the series of 0.22%. Modification of the technique--taking the biopsy with the catheter positioned centrally rather than wedged peripherally--has reduced the occurrence of capsular perforation without affecting the success rate. Transjugular liver biopsy is a valuable technique that provides diagnostic information in a high proportion of cases in which conventional percutaneous biopsy is contraindicated.     

Performance of the CKD-EPI creatinine-cystatin C glomerular filtration rate estimation equations in a multiethnic Asian population

INTRODUCTION

Clinical practice guidelines recommend using creatinine-based equations to estimate glomerular filtration rates (GFRs). While these equations were formulated for Caucasian-American populations and have adjustment coefficients for African-American populations, they are not validated for other ethnicities. The Chronic Kidney Disease-Epidemiology Collaborative Group (CKD-EPI) recently developed a new equation that uses both creatinine and cystatin C. We aimed to assess the accuracy of this equation in estimating the GFRs of participants (healthy and with chronic kidney disease [CKD]) from a multiethnic Asian population.

METHODS

Serum samples from the Asian Kidney Disease Study and the Singapore Kidney Function Study were used. GFR was measured using plasma clearance of ^99mTc-DTPA. GFR was estimated using the CKD-EPI equations. The performance of GFR estimation equations were examined using median and interquartile range values, and the percentage difference from the measured GFR.

RESULTS

The study comprised 335 participants (69.3% with CKD; 38.5% Chinese, 29.6% Malays, 23.6% Indians, 8.3% others), with a mean age of 53.5 ± 15.1 years. Mean standardised serum creatinine was 127 ± 86 µmol/L, while mean standardised serum cystatin C and mean measured GFR were 1.43 ± 0.74 mg/L and 67 ± 33 mL/min/1.73 m², respectively. The creatinine-cystatin C CKD-EPI equation performed the best, with an estimated GFR of 67 ± 35 mL/min/1.73 m².

CONCLUSION

The new creatinine-cystatin C equation estimated GFR with little bias, and had increased precision and accuracy in our multiethnic Asian population. This two-biomarker equation may increase the accuracy of population studies on CKD, without the need to consider ethnicity.     

A comparison of the thresholding strategies of micro-CT for periodontal bone loss: a pilot study

Objectives:

Micro-CT provides three-dimensional details and has been widely used for biomedical assessments. This study aimed to determine the most appropriate threshold method for quantitatively assessing the dynamics of periodontal destruction.

Methods:

Inflammation was induced by submerging a silk ligature in the sulcus of the maxillary second molars of rats, and the animals were killed prior to ligature placement and after 7 and 21 days. The maxillae were examined for the bone resorptive activities by micro-CT, histology and tartrate-resistant acid phosphatase staining. The imaging threshold was determined by CT phantom, global and local algorithms. A bone fraction measurement from each threshold-determining technique was compared with histomorphometry. The reliability and reproducibility were examined by the intraclass correlation coefficient (ICC) and the coefficient of variation.

Results:

Significant reduction of inflammatory infiltration (p < 0.01) and active osteoclastic resorption (p < 0.05) from Day 7 to Day 21 were noted. High inter- and intraexaminer agreement were demonstrated in both histomorphometric and micro-CT assessments (ICC > 0.98). The algorithm-based technique demonstrated stronger correlation to histomorphometry than phantom-based thresholds, and the highest agreement was presented by the local algorithm (ICC > 0.96). This, however, was considerably computationally expensive.

Conclusions:

The local threshold-determining algorithm is suggested for examining inflammation-induced bone loss. Further investigation will be aimed at enhancing computational efficiency.     

Synthesis of cobalamin coenzymes by human lymphocytes in vitro and the effect of folates and metabolic inhibitors

The uptake of 57Co-cyanocobalamin (CN-Cbl) and its conversion to 5- deoxyadenosylcobalamin (Ado-Cbl), methylcobalamin (Me-Cbl), and hydroxocobalamin (OH-Cbl) has been studied in phytohemagglutinin (PHA)- transformed lymphocytes from normal subjects and patients with patients with pernicious anemia. Uptake and conversion were much greater by PHA- stimulated lymphocytes than by mature non-transformed lymphocytes. In normal cells, uptake of 57Co-CN-Cbl and synthesis of the cobalamin coenzymes were approximately linear between 3 and 48 hr incubation. Ado- Cbl was the major cobalamin formed, and after 72 hr the cells contained about twice as much Ado-Cbl as Me-Cbl. Uptake by lymphocytes from patients with untreated pernicious anemia (PA) was greater than that by normal lymphocytes, but the proportions of Ado-Cbl and Me-Cbl synthesized by each were similar. Folic acid and methyltetrahydrofolate enhanced synthesis of Me-Cbl both in normal and in PA cells, while methotrexate and 5-fluorouracil depressed it. This depression was overcome by 5-formyltetrahydrofolate, suggesting that an uninterrupted folate cycle may play an important role in Me-Cbl synthesis.     

镁及镁合金在仿生体液中的腐蚀降解行为

目的:观察纯镁及镁锌系列合金在仿生体液中的腐蚀行为,分析其是否具有生物临床应用价值。方法:实验采用纯镁(99.9%)、镁锌锆(ZK60)、镁锌锆钇(Mg-5.6Zn-0.55Zr-0.9Y)3种合金材料,将试样分别放入仿生溶液中浸泡10d,仿生溶液恒温(37.0±0.5)℃。用BP211D电子天平测量了试样在仿生体液中的腐蚀失重,用LK98BII型电化学系统测量了试样在仿生体液中腐蚀时的Tafel曲线,同时观察仿生溶液pH值的变化结果:①在仿生体液中242h后,纯镁、镁锌锆和镁锌锆钇损失量分别为0.9%,3.1%和抗蚀性1.7%。②在实验条件下,腐蚀电流密度纯镁为2.03mA/mm2,镁锌锆为10.14mA/mm2,镁锌锆钇为4.42mA/mm2。③随着镁合金在仿生体液中浸泡时间延长,溶液的pH值增高,电势也随着pH值的增加而减小,镁及镁合金的腐蚀速率会降低。结论:①合金中杂质元素越少,耐腐蚀性能越好,选择纯镁或含Y的镁合金作为镁基生物材料的耐蚀性较好。②在镁锌合金中添加钇后其耐体液腐蚀性能得到了改善。     

Hippocampal volumes are larger in postmenopausal women using estrogen therapy compared to past users, never users and men: a possible window of opportunity effect

Considerable evidence suggests that estrogen can have neuroprotective effects. However, recent results raised important questions regarding the conditions under which hormone therapy (HT) following menopause can be beneficial. It has been suggested that variables such as time of initiation and duration of HT use are of critical importance for beneficial cognitive effects to be observed. The aim of the present study was to investigate the potential neuroprotective effects of estrogens in aging on brain regions with high levels of estrogen receptors, namely the hippocampus (HC) and the amygdala (AG). In order to better characterize the punctual and long-term effects of estrogens, we tested postmenopausal women currently using estrogen therapy alone (ET), past HT users, never users, and men. Age at menses, age at menopause, HT duration and age were included as covariates in the analysis. Results demonstrate that women using ET had larger left and right HC volumes compared to men, and larger right HC volumes compared to past users and never users. Importantly, we found a significant negative relationship between ET duration and HC volume in this group. The observed effects were region-specific since no significant differences could be observed for the AG. In summary, these findings support a treatment duration dependent neuroprotective role of estrogen on HC volume in aging.     

International variation in GP treatment strategies for subclinical hypothyroidism in older adults: a case-based survey

Background

There is limited evidence about the impact of treatment for subclinical hypothyroidism, especially among older people.

Aim

To investigate the variation in GP treatment strategies for older patients with subclinical hypothyroidism depending on country and patient characteristics.

Design and setting

Case-based survey of GPs in the Netherlands, Germany, England, Ireland, Switzerland, and New Zealand.

Method

The treatment strategy of GPs (treatment yes/no, starting-dose thyroxine) was assessed for eight cases presenting a woman with subclinical hypothyroidism. The cases differed in the patient characteristics of age (70 versus 85 years), vitality status (vital versus vulnerable), and thyroid-stimulating hormone (TSH) concentration (6 versus 15 mU/L).

Results

A total of 526 GPs participated (the Netherlands n = 129, Germany n = 61, England n = 22, Ireland n = 21, Switzerland n = 262, New Zealand n = 31; overall response 19%). Across countries, differences in treatment strategy were observed. GPs from the Netherlands (mean treatment percentage 34%), England (40%), and New Zealand (39%) were less inclined to start treatment than GPs in Germany (73%), Ireland (62%), and Switzerland (52%) (P = 0.05). Overall, GPs were less inclined to start treatment in 85-year-old than in 70-year-old females (pooled odds ratio [OR] 0.74 [95% confidence interval [CI] = 0.63 to 0.87]). Females with a TSH of 15 mU/L were more likely to get treated than those with a TSH of 6 mU/L (pooled OR 9.49 [95% CI = 5.81 to 15.5]).

Conclusion

GP treatment strategies of older people with subclinical hypothyroidism vary largely by country and patient characteristics. This variation underlines the need for a new generation of international guidelines based on the outcomes of randomised clinical trials set within primary care.