Discrimination between non-functioning pituitary adenomas and hypophysitis using machine learning methods based on magnetic resonance imaging‑derived texture features

Purpose

Hypophysitis is a heterogeneous condition that includes inflammation of the pituitary gland and infundibulum, and it can cause symptoms related to mass effects and hormonal deficiencies. We aimed to evaluate the potential role of machine learning methods in differentiating hypophysitis from non-functioning pituitary adenomas.

Methods

The radiomic parameters obtained from T1A-C images were used. Among the radiomic parameters, parameters capable of distinguishing between hypophysitis and non-functioning pituitary adenomas were selected. In order to avoid the effects of confounding factors and to improve the performance of the classifiers, parameters with high correlation with each other were eliminated. Machine learning algorithms were performed with the combination of gray-level run-length matrix-low gray level run emphasis, gray-level co-occurrence matrix-correlation, and gray-level co-occurrence entropy.

Results

A total of 34 patients were included, 17 of whom had hypophysitis and 17 had non-functioning pituitary adenomas. Among the 38 radiomics parameters obtained from post-contrast T1-weighted images, 10 tissue features that could differentiate the lesions were selected. Machine learning algorithms were performed using three selected parameters; gray level run length matrix-low gray level run emphasis, gray-level co-occurrence matrix-correlation, and gray level co-occurrence entropy. Error matrices were calculated by using the machine learning algorithm and it was seen that support vector machines showed the best performance in distinguishing the two lesion types.

Conclusions

Our analysis reported that support vector machines showed the best performance in distinguishing hypophysitis from non-functioning pituitary adenomas, emphasizing the importance of machine learning in differentiating the two lesions.

     

Pulsed Doppler tissue imaging can help to identify patients with right ventricular infarction

This study was planned to assess whether tissue Doppler imaging is a useful method for the detection of the right ventricular myocardial infarction. Forty-eight patients with acute inferior myocardial infarction and 24 age- and sex-matched healthy controls were included in this study. Twenty-four patients had electrocardiographic signs of inferior myocardial infarction without right ventricular infarction (group I), and the other 24 patients had electrocardiographic signs of inferior myocardial infarction with right ventricular infarction (group II). From the echocardiographic apical four-chamber view, peak systolic, early diastolic, and late diastolic velocities of the tricuspid annulus at the right ventricular free wall were recorded with the use of pulsed-wave Doppler tissue imaging. The tricuspid annular peak tissue Doppler imaging systolic velocity was significantly lower in group I (14.03 ± 2.57cm/s, P 0.005) and in group II (8.50 ± 0.84cm/s, P 0.005) than in controls (16.63 ± 2.31cm/s). The tricuspid annular peak systolic (8.50 ± 0.84cm/s vs 16.63 ± 2.31cm/s) and peak early diastolic (10.99 ± 3.28cm/s vs 19.39 ± 4.3cm/s) velocities were significantly lower in group II than in group I, as compared with controls (P 0.001). Peak early diastolic velocity of tricuspid annulus (10.99 ± 3.28cm/s vs 19.39 ± 4.3cm/s) was significantly lower in group I than in controls (P 0.001); however, late diastolic velocity was significantly lower in group II (15.98 ± 5.08cm/s, P 0.05) than in group I (18.21 ± 2.63cm/s, P 0.05) and in controls (19.02 ± 5.29cm/s). The results of this study indicate that tricuspid annular peak systolic and early diastolic velocities are reduced in patients with right ventricular infarction. The velocity of the tricuspid annulus by tissue Doppler imaging is simple and can be used to distinguish whether patients with inferior myocardial infarction have right ventricular infarction.This study was presented at the XXIII. Congress of the European Society of Cardiology, Stockholm, Sweden, 1–5 September 2001     

Melatonin ameliorates oxidative organ damage induced by acute intra-abdominal compartment syndrome in rats

Acutely increased intra-abdominal pressure (IAP) can lead to multiple organ failure. As blood flow to intra-abdominal organs is reduced by high venous resistance, ischemia-reperfusion (I/R) injury plays an important role in the pathogenesis of abdominal compartment syndrome (ACS) following IAP. Melatonin, a secretory product of the pineal gland, is known to have free radical scavenging and antioxidative properties in several oxidative processes. The objective of this study was to examine the potential protective properties of melatonin on the oxidative organ damage in a rat model of ACS. Under ketamine anesthesia, an arterial catheter was inserted intraperioneally (i.p.) and using an aneroid manometer connected to the catheter, IAP was kept at 20 mmHg (ischemia group; I) for 1 hr. In the ischemia/reperfusion (I/R) group, pressure applied for an hour was decompressed and a 1-hr reperfusion period was allowed. In another IR group, melatonin was administered (10 mg/kg, i.p.) immediately before the decompression of IAP. The results demonstrate that tissue levels of malondialdehyde (MDA) and myeloperoxidase activity (MPO; index of tissue neutrophil infiltration) were elevated, while glutathione (GSH; a key to antioxidant) levels were reduced in both I and I/R groups (P < 0.05-0.001). Melatonin treatment in I/R rats reversed these changes (P < 0.01-0.001). Moreover, melatonin given to the I/R group reduced the elevations in serum aspartate aminotransferase, alanine aminotransferase and blood urea nitrogen levels and abolished the increase in serum creatinine levels. Our results indicate that melatonin, because of antioxidant and free radical scavenging properties, ameliorates reperfusion-induced oxidative organ damage. In conclusion, the results of the present study suggest that the therapeutic value of melatonin as a 'reperfusion injury-limiting' agent must be considered in ACS.     

Plasma homocysteine levels in polycystic ovary syndrome and congenital adrenal hyperplasia

The purpose of this study was to determine whether polycystic ovary syndrome (PCOS) and nonclassic 21-hydroxylase deficiency (CAH) are related to hyperhomocysteinemia, and to investigate if there is a correlation between homocysteine levels and insulin sensitivity in women with PCOS and CAH. Fifty patients with PCOS, 50 patients with CAH and 25 control women were included in the study. Blood samplings were performed in the early follicular phase for measuring hormone profile, Vitamin B(12), folate, homocysteine levels and fasting blood glucose. Ovulatory status was assessed with timed serum progesterone measurements. Homeostasis model assessment-insulin resistance (HOMA-IR) was calculated as a measure of insulin resistance. Mean homocysteine levels were found as (8.9 + 1.9 micromol/l and 17.7 + 3.6 micromol/l) in the normal group and PCOS respectively (p<0.001), but there was no statistical significance between nonclassic 21-hydroxylase deficiency (9.0 + 2.2 micromol/l) and control group. Most of the patients in PCOS group (35 of 50) were significantly insulin resistant. However, there was no insulin resistant patient in CAH or control group. When we compare the two subgroups of PCOS women, the patients with insulin resistance had significantly higher homocysteine levels than the ones who were not insulin resistant. There were positive correlations among serum homocysteine, insulin and androgen levels in PCOS patients. There were no correlations among these parameters in CAH and control groups. Increased homocysteine levels may contribute to increased cardiovascular disease risk in patients with PCOS. The reason for hyperhomocysteinemia seems to be related to insulin resistance but not high androgen levels.     

Lack of association of hepatic estrogen receptor-alpha expression with histopathological and biochemical findings in chronic hepatitis C

Estrogens exert a protective effect against hepatic steatosis and fibrosis. Loss of estrogen receptor-alpha (ER-α) in the liver is associated with hepatic steatosis and inflammation in animal models. We conducted a study in order to investigate the presence and extent of ER-α expression in HCV infection, and its relationship with histological and biochemical findings. Ninety biopsy-proven chronic hepatitis C (CHC) patients were enrolled in the study. Liver biopsy specimens were immunohistochemically stained for ER-α expression. Nuclear ER-α expression percentage was calculated. ER-α was positive in 69 of the patients (76%). ER-α positive and negative groups were not significantly different in terms of age, gender, necroinflammatory activity, fibrosis, steatosis, serum levels of AST, ALT, ALP, GGT, and bilirubin. ER-α expression percentage was not correlated with fibrosis, steatosis, necroinflammatory activity and biochemical findings. Although estrogens are known to be protective against fibrosis and steatosis in animal models, we did not find any significant correlation between ER-α expression and histopathological and biochemical findings in CHC patients. These findings should be verified in further large scale studies.     

Comparison of the Effects of Desflurane and Propofol Anesthesia on the Inflammatory Response and S100β Protein During Coronary Artery Bypass Grafting

Cardiopulmonary bypass (CPB) contributes to the secretion of anti-inflammatory cytokines that mediate the inflammatory response observed during open heart surgery. In addition to many factors, type of anesthesia management affects immune response and central nervous system in cardiac surgery. The aim of this study was to assess the effect of propofol versus desflurane anesthesia on systemic immune modulation and central nervous system on patients undergoing coronary artery bypass grafting. Forty patients undergoing elective coronary artery bypass graft surgery with CPB were included in this prospective randomized study. Patients were allocated to receive propofol (n?=?20) or desflurane (n?=?20) for maintenance of anesthesia. The blood samples for IL-6, IL-8, TNF-α, and S100β were drawn just prior to the operation before the induction of anesthesia, second before cardiopulmonary bypass, third after CPB, fourth 4 h postoperatively at the ICU. Major finding in our study is that S100β levels were lower in propofol group when compared to desflurane anesthesia. And also immune reaction was less in patients exposed to desflurane anesthesia when compared to propofol anesthesia as indicated by lower plasma concentrations of IL-8 and IL-6. Propofol is more preferable in terms of S100β for anesthetic management for CABG.     

The Role of Serum Procalcitonin Levels in Predicting Ascitic Fluid Infection in Hospitalized Cirrhotic and Non-cirrhotic Patients

Objective: To determine the role of serum procalcitonin levels in predicting ascites infection in hospitalized cirrhotic and non-cirrhotic patients.Methods: A total of 101 patients (mean age: 63.4±1.3, 66.3% were males) hospitalized due to cirrhosis (n=88) or malignancy related (n=13) ascites were included in this study. Spontaneous bacterial peritonitis (SBP, 19.8%), culture-negative SBP (38.6%), bacterascites (4.9%), sterile ascites (23.8%) and malign ascites (12.9%) groups were compared in terms of procalcitonin levels in predicting ascites infection. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of procalcitonin levels and predicting outcome of procalcitonin levels was compared with C-reactive protein (CRP).Results: Culture positivity was determined in 26.7% of overall population. Serum procalcitonin levels were determined to be significantly higher in patients with positive bacterial culture in ascitic fluid compared to patients without culture positivity (median (min-max): 4.1 (0.2-36.4) vs. 0.4 (0.04-15.8), p<0.001). Using ROC analysis, a serum procalcitonin level of <0.61 ng/mL in SBP (area under curve (AUC): 0.981, CI 95%: 0.000-1.000, p<0.001), <0.225 ng/mL in culture-negative SBP (AUC: 0.743, CI 95%: 0.619-0.867, p<0.001), <0.42 ng/mL in SBP and culture-negative SBP patients (AUC: 0.824, CI 95%: 0.732-0.916, p<0.001), and <1.12 ng/mL in bacterascites (AUC: 0.837, CI 95%: 0.000-1.000, p=0.019) were determined to accurately rule out the diagnosis of bacterial peritonitis. Predictive power of serum procalcitonin levels in SBP + culture-negative SBP group (AUCs: 0.824 vs 0.622, p=0.004, Fig 4), culture-positive SBP (AUCs: 0.981 vs 0.777, p=0.006, Fig 5) and (although less powerfull) in culture-negative SBP (AUCs: 0.743 vs 0.543, p=0.02, Fig 6) were found significantly higher than CRP.Conclusion: According to our findings determination of serum procalcitonin levels seems to provide satisfactory diagnostic accuracy in differentiating bacterial infections in hospitalized patients with liver cirrhosis related ascites.