Estrogen receptors in skeletal metabolism: lessons from genetically modified models of receptor function

Estrogens have long been known to be important for skeletal homeostasis, but their precise mechanisms of action in bone are still unclear. Mice with targeted deletions of the estrogen receptors alpha (ERalpha) and beta (ERbeta) have been generated by two research groups and several studies performed characterizing the phenotype of ERalpha knockout (ERKOalpha), ERbeta knockout (ERKObeta), or double deletion of ERalpha and ERbeta (DERKO) mice. Initial studies reported a reduction in bone mineral density in male ERKOalpha mice. More extensive analyses have been puzzling, likely because of compensatory mechanisms in ERKO mice. Furthermore, the existence of a third ER continues to be a potential explanation for some actions of estrogen in bone. Other rodent models, including the testicular feminized mouse and rat, the aromatase knockout mouse, and a rat with a dominant negative ER mutation, have added information regarding estrogen's actions in bone. This review summarizes many reports characterizing available rodent models with genetic alterations relevant to estrogen action. The sum of these reports suggests that the ERbeta is not highly protective in bone because loss of its function results in minimal alterations in the skeleton. Furthermore, loss of both the ERalpha and the ERbeta does not account for loss of estrogen action in bone, because the impact of DERKO is seemingly not as great as the impact of gonadectomy on the skeleton. Finally, through studies of ERKO mice and other rodent models of altered sex steroid action, it appears that estrogen may be more protective in the skeleton than androgens.     

The evaluation of acute kidney injury due to ischemia by urinary neutrophil gelatinase-induced lipocalin (uNGAL) measurement in patients who underwent partial nephrectomy

International Urology and Nephrology - To investigate the role of urinary neutrophil gelatinase-induced lipocalin (uNGAL) measurement in the early diagnosis of acute kidney injury that may occur...     

The effect of renal artery-only or renal artery–vein clamping during partial nephrectomy on short and long-term functional results: Is clamping technique important?

Purpose

To evaluate the effect of artery-only (AO) and artery–vein (AV) clamping during partial nephrectomy (PN) on short- and long-term renal function outcome.

Methods

Medical records of 154 patients in the AO group and 192 patients in the AV group who underwent open and minimally invasive (laparoscopic/robotic) PN between January 2011 and January 2018 were retrospectively assessed. Preoperative patient and tumor-specific characteristics in addition to perioperative factors and renal function outcomes were compared. The change in the estimated glomerular filtration rate (eGFR) from postoperative 1–3 days, 12 and 24 months after surgery was calculated. Acute kidney injury (AKI) was defined a as a?>?25% reduction in eGFR.

Results

There were no statistically significant differences between the clamping techniques in terms of postoperative 1–3 days, 12 and 24 months eGFR change percentage and risk of progression to chronic kidney disease (CKD). No significant difference in short- and long-term renal functions was found between the minimally invasive or open AO and AV clamping subgroups at any time point. In multivariate analysis, the R.E.N.A.L score (AO group p?=?0.026, AV group p?<?0.001) and preoperative eGFR (AO group p?<?0.001, AV group p?=?0.010) were strong predictors of the acute kidney injury in both groups. Older age (AO group p?=?0.045, AV group p?=?0.010) and preoperative eGFR (AO group p?=?0.008, AV group p?=?0.002) were significantly associated with CKD progression at 2-year follow-up in both groups.

Conclusion

AV clamping does not adversely affect postoperative renal function compared to AO clamping. Preoperative patient- and tumor-related factors are more important for renal function regardless of the clamping technique.

     

A New Approach to Tertiary Hyperparathyroidism: Percutaneous Embolization: Two Case Reports

Secondary hyperparathyroidism is one of the most common complications of chronic kidney failure. If prolonged, parathyroid hormone release gains autonomy and tertiary hyperparathyroidism with parathyroid adenoma or hyperplasia can be develop. Tertiary hyperparathyroidism is associated with increased risk of mortality and morbidity; thus, treatment is recommended. Medical treatment includes phosphate binders, vitamin D analogues, and calcimimetic agents. Most cases of tertiary hyperparathyroidism can be controlled with medical treatment. When medical treatment options prove insufficient, parathyroidectomy is recommended. However, recurrence after parathyroidectomy is possible, which requires an alternative treatment. We present our percutaneous embolization experience, which has not been tried in the treatment of tertiary hyperparathyroidism in renal transplantation patients diagnosed with tertiary hyperparathyroidism.     

The “vaccine” hubbub: Viral load comparisons of SARS-CoV-2 Delta and Omicron variants against different vaccine–booster vaccine combinations

There is a significant body of evidence showing that efficient vaccination schemes against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is helping control the coronavirus disease 2019 (COVID-19) pandemic. However, this goal cannot be achieved without real world data highlighting the impact of vaccines against viral spread. In this study, we have aimed at differentially investigating the impact of COVID-19 vaccines (CoronaVac, Pfizer/BioNTech, Astra/Zeneca Oxford, Janssen) used in North Cyprus in limiting the viral load of Delta and Omicron variants of SARS-COV-2. We have utilized real-time quantitative polymerase chain reaction cycle threshold values (Ct values) as a proxy of viral load of the two SARS-CoV-2 variants. Our results indicate that the administration of at least two doses of the messenger RNA-based Pfizer/BioNTech vaccine leads to the lowest viral load (highest Ct values) obtained for both Omicron and Delta variants. Interestingly, regardless of the vaccine type used, our study revealed that Delta variant produced significantly higher viral loads (lower Ct values) compared with the Omicron variant, where the latter was more commonly associated with younger patients. Viral spread is a crucial factor that can help determine the future of the pandemic. Thus, prioritizing vaccines that will play a role in not only preventing severe disease but also in limiting viral load and spread may contribute to infection control strategies.     

Incremental value of live/real time three‐dimensional transesophageal echocardiography over the two‐dimensional technique in the assessment of a tuberculoma involving the left atrium and appendage

Intracardiac tuberculomas are extremely rare, and cardiac involvement in tuberculosis accounts for only 0.5% of extrapulmonary tuberculosis. We report for the first time incremental value of live/real time three‐dimensional transesophageal echocardiography over two‐dimensional transesophageal echocardiography in the assessment of a tuberculoma involving the left atrium and left atrial appendage.