A curative treatment strategy using tumor debulking surgery combined with immune checkpoint inhibitors for advanced pediatric solid tumors: An in vivo study using a murine model of osteosarcoma

Background/purpose

This study aimed to assess the significance of tumor debulking surgery by using immune checkpoint inhibitors for advanced pediatric solid tumors in a murine model of advanced osteosarcoma.

Optimal conditions and the advantages of using laser microdissection and liquid chromatography tandem mass spectrometry for diagnosing renal amyloidosis

Background

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has recently been utilized to accurately detect the amyloid proteins of renal amyloidosis. The present study investigated the optimal procedures for analyzing samples by LCMS/MS, and the advantage of using this technique to diagnosis renal amyloidosis.

Methods

To detect amyloid proteins, laser microdissected glomeruli from AL (n?=?13) or AA (n?=?10) renal amyloidosis patients were digested and analyzed by LCMS/MS. To determine the best procedures for analyzing samples by LCMS/MS, we examined the suitability of tissue samples, frozen or formalin-fixed paraffin-embedded (FFPE), the number of dissected glomeruli required for analysis (2, 10, or 50 glomeruli), and the amount of trypsin with or without dithiothreitol (DTT). We additionally compared the detection of amyloid proteins between immunostaining and LCMS/MS.

Results

Examining 10 dissected glomeruli from FFPE sections digested with trypsin 3 µL (0.1 mg/mL) without DDT made it possible to detect amyloid protein in all 10 AA and in 10 out of 12 AL amyloidosis cases. All AA amyloidosis cases were diagnosed using immunohistochemistry for amyloid A. With immunostaining, however, there were several inconclusive immunoglobulin and/or their light chain staining noted in the AA or AL amyloidosis cases. Even so, LCMS/MS was able to accurately detect amyloid protein in renal amyloidosis.

Conclusion

The use of 10 laser microdissected glomeruli (170,000–220,000 µm²) with amyloid deposition from FFPE sections digested with trypsin 3 µL (0.1 mg/mL) allowed the accurate detection of amyloid protein in AA and AL amyloidosis.

     

Clinicopathological analysis of biopsy-proven diabetic nephropathy based on the Japanese classification of diabetic nephropathy

Background

The Japanese classification of diabetic nephropathy reflects the risks of mortality, cardiovascular events and kidney prognosis and is clinically useful. Furthermore, pathological findings of diabetic nephropathy are useful for predicting prognoses. In this study, we evaluated the characteristics of pathological findings in relation to the Japanese classification of diabetic nephropathy and their ability to predict prognosis.

Methods

The clinical data of 600 biopsy-confirmed diabetic nephropathy patients were collected retrospectively from 13 centers across Japan. Composite kidney events, kidney death, cardiovascular events, all-cause mortality, and decreasing rate of estimated GFR (eGFR) were evaluated based on the Japanese classification of diabetic nephropathy.

Results

The median observation period was 70.4 (IQR 20.9–101.0) months. Each stage had specific characteristic pathological findings. Diffuse lesions, interstitial fibrosis and/or tubular atrophy (IFTA), interstitial cell infiltration, arteriolar hyalinosis, and intimal thickening were detected in more than half the cases, even in Stage 1. An analysis of the impacts on outcomes in all data showed that hazard ratios of diffuse lesions, widening of the subendothelial space, exudative lesions, mesangiolysis, IFTA, and interstitial cell infiltration were 2.7, 2.8, 2.7, 2.6, 3.5, and 3.7, respectively. Median declining speed of eGFR in all cases was 5.61 mL/min/1.73 m²/year, and the median rate of declining kidney function within 2 years after kidney biopsy was 24.0%.

Conclusions

This study indicated that pathological findings could categorize the high-risk group as well as the Japanese classification of diabetic nephropathy. Further study using biopsy specimens is required to clarify the pathogenesis of diabetic kidney disease.

     

Induction of hibernation-like hypothermia by central activation of the A1 adenosine receptor in a non-hibernator,the rat

Central adenosine A1-receptor (A1AR)-mediated signals play a role in the induction of hibernation. We determined whether activation of the central A1AR enables rats to maintain normal sinus rhythm even after their body temperature has decreased to less than 20 °C. Intracerebroventricular injection of an adenosine A1 agonist, N6-cyclohexyladenosine (CHA), followed by cooling decreased the body temperature of rats to less than 20 °C. Normal sinus rhythm was fundamentally maintained during the extreme hypothermia. In contrast, forced induction of hypothermia by cooling anesthetized rats caused cardiac arrest. Additional administration of pentobarbital to rats in which hypothermia was induced by CHA also caused cardiac arrest, suggesting that the operation of some beneficial mechanisms that are not activated under anesthesia may be essential to keep heart beat under the hypothermia. These results suggest that central A1AR-mediated signals in the absence of anesthetics would provide an appropriate condition for maintaining normal sinus rhythm during extreme hypothermia.