Prediction of pseudoprogression and long-term outcome of vestibular schwannoma after Gamma Knife radiosurgery based on preradiosurgical MR radiomics

BACKGROUND AND PURPOSE

Gamma Knife radiosurgery (GKRS) is a safe and effective treatment modality with a long-term tumor control rate over 90% for vestibular schwannoma (VS). However, numerous tumors may undergo a transient pseudoprogression during 6-18 months after GKRS followed by a long-term volume reduction. The aim of this study is to determine whether the radiomics analysis based on preradiosurgical MRI data could predict the pseudoprogression and long-term outcome of VS after GKRS.

MATERIALS AND METHODS

A longitudinal dataset of patients with VS treated by single GKRS were retrospectively collected. Overall 336 patients with no previous craniotomy for tumor removal and a median of 65-month follow-up period after radiosurgery were finally included in this study. In total 1763 radiomic features were extracted from the multiparameteric MRI data before GKRS followed by the machine-learning classification.

RESULTS

We constructed a two-level machine-learning model to predict the long-term outcome and the occurrence of transient pseudoprogression after GKRS separately. The prediction of long-term outcome achieved an accuracy of 88.4% based on five radiomic features describing the variation of T2-weighted intensity and inhomogeneity of contrast enhancement in tumor. The prediction of transient pseudoprogression achieved an accuracy of 85.0% based on another five radiomic features associated with the inhomogeneous hypointensity pattern of contrast enhancement and the variation of T2-weighted intensity.

CONCLUSION

The proposed machine-learning model based on the preradiosurgical MR radiomics provides a potential to predict the pseudoprogression and long-term outcome of VS after GKRS, which can benefit the treatment strategy in clinical practice.

Retinol-binding protein 4 is associated with impaired glucose regulation and microalbuminuria in a Chinese population

AIMS/HYPOTHESIS

Increased retinol-binding protein 4 (RBP4) has been reported in association with insulin resistance and type 2 diabetes. We aimed to investigate the association of serum RBP4 with impaired glucose regulation and microalbuminuria in Chinese adults aged 40 years or older.

METHODS

Serum RBP4 was measured in 763 individuals with normal glucose regulation, 508 with impaired glucose regulation and 524 newly diagnosed diabetic patients. Serum RBP4 was measured using ELISA and urine albumin/creatinine ratio was used to determine the urinary albumin excretion.

RESULTS

Serum RBP4 concentrations were significantly higher in participants with isolated impaired fasting glucose, isolated impaired glucose tolerance, combined impaired fasting glucose/impaired glucose tolerance and diabetes than in those with normal glucose regulation, whereas serum RBP4 levels were not different in the four groups with dysregulation of glucose metabolism. RBP4 was associated with a higher risk for impaired glucose regulation (OR 1.011 for each 1 microg/ml increase in RBP4, 95% CI 1.000-1.022, p = 0.04) after adjustment for sex, age, BMI, current smoking and alcohol intake, family history of diabetes, insulin resistance, triacylglycerol, total cholesterol, and HDL- and LDL-cholesterol; the corresponding OR of combined impaired glucose regulation and type 2 diabetes was 1.022 (95% CI 1.009-1.035, p = 0.0009). RBP4 was associated with the risk of microalbuminuria (OR 1.023, 95% CI 1.004-1.042, p = 0.01) after adjustment for sex, age, smoking habit and alcohol intake, BMI, waist/hip ratio, homeostasis model assessment of insulin resistance, GFR, triacylglycerol, total cholesterol, and HDL- and LDL-cholesterol.

CONCLUSIONS/INTERPRETATION

Serum RBP4 level is closely associated with impaired glucose regulation and is an independent risk factor for microalbuminuria.

A recurrent chromosome breakpoint in breast cancer at the NRG1/neuregulin 1/heregulin gene

Most studies of genomic rearrangements in common cancers have focused on regional gains and losses, but some rearrangements may break within specific genes. We previously reported that five breast cancer cell lines have chromosome translocations that break in the NRG1 gene and that could cause abnormal NRG1 expression. NRG1 encodes the Neuregulins 1 (formerly the Heregulins), ligands for members of the ErbB/epidermal growth factor-receptor family, which includes ErbB2/HER2. We have now screened for breaks at NRG1 in paraffin sections of breast tumors. Tissue microarrays were screened by fluorescence in situ hybridization, with hybridization probes proximal and distal to the expected breakpoints. This screen detects breaks but does not distinguish between translocation or deletion breakpoints. The screen was validated with array-comparative genomic hybridization on a custom 8p12 high-density genomic array to detect a lower copy number of the sequences that were lost distal to the breaks. We also precisely mapped the breaks in five tumors with different hybridization probes. Breaks in NRG1 were detected in 6% (19 of 323) of breast cancers and in some lung and ovarian cancers. In an unselected series of 213 cases with follow-up, breast cancers where the break was detected tended to be high-grade (65% grade III compared with 28% of negative cases). They were, like breast tumors in general, mainly ErbB2 low (11 of 13 were low) and estrogen receptor positive (11 of 13 positive).

A recurrent chromosome translocation breakpoint in breast and pancreatic cancer cell lines targets the neuregulin/NRG1 gene

The 8p11-21 region is a frequent target of alterations in breast cancer and other carcinomas. We surveyed 34 breast tumor cell lines and 9 pancreatic cancer cell lines for alterations of this region by use of multicolor fluorescence in situ hybridization (M-FISH) and BAC-specific FISH. We describe a recurrent chromosome translocation breakpoint that targets the NRG1 gene on 8p12. NRG1 encodes growth factors of the neuregulin/heregulin-1 family that are ligands for tyrosine kinase receptors of the ERBB family. Breakpoints within the NRG1 gene were found in four of the breast tumor cell lines: ZR-75-1, in a dic(8;11); HCC1937, in a t(8;10)(p12;p12.1); SUM-52, in an hsr(8)(p12); UACC-812, in a t(3;8); and in two of the pancreatic cancer cell lines: PaTu I, in a der(8)t(4;8); and SUIT-2, in a del(8)(p). Mapping by two-color FISH showed that the breaks were scattered over 1.1 Mb within the NRG1 gene. It is already known that the MDA-MB-175 breast tumor cell line has a dic(8;11), with a breakpoint in NRG1 that fuses NRG1 to the DOC4 gene on 11q13. Thus, we have found a total of seven breakpoints, in two types of cancer cell lines, that target the NRG1 gene. This suggests that the NRG1 locus is a recurring target of translocations in carcinomas. PCR analysis of reverse-transcribed cell line RNAs revealed an extensive complexity of the NRG1 transcripts but failed to detect a consistent pattern of mRNA isoforms in the cell lines with NRG1 breakpoint.

Modified plication of the tunica albuginea in treating congenital penile curvature

OBJECTIVE

To describe a modified plication technique and compare the results with the Nesbit procedure for treating congenital penile curvature.

PATIENTS AND METHODS

Eleven men with congenital penile curvature were treated by a modified tunica albuginea plication technique. An artificial erection was induced by normal saline injection; in the areas where plication was planned, Buck's fascia was opened longitudinally and dissected a short distance toward the midline to free the neurovascular bundles. Allis clamps were used to grasp the tunica albuginea and "bumps" created. Two interrupted U-shaped sutures using 2/0 polyglactin were placed underneath each Allis clamp to secure the bump. The results were analysed retrospectively and compared with the results of 11 other men treated using the Nesbit procedure.

RESULTS

The mean (range) follow-up was 25 (12-47) months for the Nesbit procedure and 15 (8-26) months for the modified plication procedure. In the Nesbit group, eight patients had satisfactory cosmetic and functional results; three complained of penile shortening and one had erectile dysfunction. In the modified plication group, 10 patients reported satisfactory cosmetic and functional results; one complained of penile shortening, two were concerned about the indurations of the penis but none had erectile dysfunction.

CONCLUSIONS

The modified plication technique is easier to perform, is more often successful and causes fewer surgical complications than the Nesbit procedure for treating congenital penile curvature.

Coronary artery stenosis in rats affects beta-adrenergic receptor signaling in myocytes

OBJECTIVE

The purpose of this study was to determine whether the early chronic ischemic cardiomyopathy produced by non-occlusive coronary artery constriction was characterized by alterations in the regulation of beta-adrenoreceptor (beta-AR) signaling.

METHODS

Coronary artery narrowing was surgically induced in rats and the animals sacrificed at 7 and 14 days. The changes in the biochemical properties of the multiple components of the beta-AR pathway were examined in enzymatically dissociated myocytes.

RESULTS

Coronary stenosis, involving an average 55% reduction in luminal diameter, was associated with left ventricular failure and right ventricular dysfunction at both time intervals. A decrease in the quantity of beta-AR was detected at 7 days and preceded the loss of high-affinity binding sites. This regulatory modification was characterized by a reduction in beta 1 and beta 2 receptors and a shift in the isoproterenol dose response curve indicating a functional correlation between the decrease in beta-AR and attenuated inotropic support of the myocardium. The percentage of beta-AR binding agonist with high affinity decreased significantly at 14 days along with a further reduction in the density of beta 1 and beta 2 receptors. Reconstitution studies with cyc S49 lymphoma cells did not detect an impairment of Gs alpha functional activity, but the quantity of Gi alpha was increased at both intervals. Finally, activation of the catalytic unit of adenylyl cyclase by forskolin and GTP was not altered by coronary stenosis, however, basal cyclic AMP in myocytes was depressed at 14 days.

CONCLUSIONS

Coronary stenosis induces distinct and progressive modifications in the beta-AR signaling cascade which may contribute to the impaired ventricular performance in this model of myocardial ischemia.

[Complications of percutaneous renal biopsy: an analysis of 1000 consecutive biopsies]

The complications of percutaneous renal biopsies in 1000 cases are analysed in this paper. Because the modern techniques for biopsy localization and operation were used, both accidental puncture of other organs and infection were avoided. However, the hemorrhage of renal wound was still a predominate complication. Gross hematuria developed in 7.4% of biopsies, perirenal hematomas 4.4% of biopsies, and serious renal bleeding complications, including arteriovenous fistula, requiring transfusion of more than 1000 ml of blood were detected in 0.6% of biopsies. In this paper the manifestations, diagnosis and treatment for every renal bleeding complication are discussed. It is emphasized that renal arteriography should be done for the patients with persistent or recurrent renal hemorrhage, and that selective arterial embolization by using self-blood coagulative pieces should be considered before deciding surgical correction of these serious bleeding complications.

ANG II receptors, c-myc, and c-jun in myocytes after myocardial infarction and ventricular failure

To determine the relationship between reactive cardiac hypertrophy and the expression of angiotensin II (ANG II) receptors in surviving myocytes after infarction, large infarcts were produced in rats that were killed 2-3 days later. Measurements of global ventricular dynamics indicated that left ventricular failure and right ventricular dysfunction occurred in experimental animals. These alterations in ventricular pump function were associated with increases in ventricular weight-to-body weight ratio, indicative of developing cardiac hypertrophy. Such a response was coupled with a 6.6-fold increase in ANG II receptor mRNA in myocytes from the left ventricle. A 2.3-fold increase in the expression of ANG II receptor in myocytes from the right ventricle was also found. Radioligand binding assay documented a 44% increase in the density of ANG II receptors on left ventricular myocytes of infarcted hearts. To establish whether the induction of genes commonly associated with myocyte hypertrophy was present, the message for c-myc and c-jun was biventricularly assessed. Myocardial infarction was accompanied by overexpressions of c-myc and c-jun that were more prominent in left than in right ventricular myocytes. In conclusion, the enhanced expression of ANG II receptor and its receptor protein and c-myc and c-jun in myocytes may participate in the reactive growth processes of these cells after infarction.