Hypoxia Altitude Simulation and Reduction of Cerebral Oxygenation in COPD Patients.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is highly prevalent and often associated with chronic hypoxia. Previous studies have shown alterations of cerebral oxygenation and cardiac repolarization in COPD patients (GOLD stage II-IV). Airplane travel is common in patients with COPD; however, the clinical effects of a diminished oxygen partial pressure in aircraft cabin environments at cruising altitude remain elusive. The aim of this study was to assess changes of cerebral oxygenation as well as parameters of cardiac repolarization during a hypoxia altitude simulation combined with mild physical activity in these patients.METHODS: Patients with COPD and healthy subjects (10 per group) randomly selected from the Charité outpatient clinic conducted a hypoxia altitude simulation test which consisted of three phases. The regional cerebral oxygen saturation (rSO2) of the frontal cortex was measured at rest using near-infrared spectroscopy (NIRS). Furthermore, oxygen saturation (SpO2), blood pressure, and heart rate values, as well as a 12-lead-ECG, were recorded. Subsequently, a mild treadmill exercise program (25 W) was divided into 10 min of normoxia (pre-hypoxia), 30 min of mild hypoxia (FIO2 = 0.15), followed by a second 10-min period of normoxia (post-hypoxia). Meanwhile, mentioned parameters were recorded in 2-min intervals. P, PQ, QRS, QT, QTc, QTd, T-peak-T-end interval (TpTe), and corrected TpTe (TpTec) were measured on three ECG complexes, each at baseline, at the end of the normoxic phase, and at the end of the hypoxic phase.RESULTS: A total of 10 patients with COPD and 10 control subjects were included in this study. SpO2 was significantly lower in COPD patients throughout the whole test. Frontal cerebral rSO2 was significantly lower in the left hemisphere during hypoxia altitude simulation in COPD patients (59.5 ± 8.5 vs. 67.5 ± 5.7).CONCLUSIONS: We show reduced left frontal cerebral oxygenation during hypoxia and mild exercise in patients with COPD, suggesting diminished altitude resilience and altitude capabilities. Preflight hypoxia assessment might be recommended to patients with severe COPD.Dehe L, Hohendanner F, Gültekin E, Werth G, Wutzler A, Bender TO. Hypoxia altitude simulation and reduction of cerebral oxygenation in COPD patients. Aerosp Med Hum Perform. 2023; 94(3):102-106.

Added Value of Tomoelastography for Characterization of Pancreatic Neuroendocrine Tumor Aggressiveness Based on Stiffness.

PURPOSE: To evaluate the diagnostic performance of tomoelastography in differentiating pancreatic neuroendocrine tumors (PNETs) from healthy pancreatic tissue and to assess the prediction of tumor aggressiveness by correlating PNET stiffness with PET derived asphericity. METHODS: 13 patients with PNET were prospectively compared to 13 age-/sex-matched heathy volunteers (CTR). Multifrequency MR elastography was combined with tomoelastography-postprocessing to provide high-resolution maps of shear wave speed (SWS in m/s). SWS of pancreatic neuroendocrine tumor (PNET-T) were compared with nontumorous pancreatic tissue in patients with PNET (PNET-NT) and heathy pancreatic tissue (CTR). The diagnostic performance of tomoelastography was evaluated by ROC-AUC analysis. PNET-SWS correlations were calculated with Pearson's r. RESULTS: SWS was higher in PNET-T (2.02 ± 0.61 m/s) compared to PNET-NT (1.31 ± 0.18 m/s, p < 0.01) and CTR (1.26 ± 0.09 m/s, p < 0.01). An SWS-cutoff of 1.46 m/s distinguished PNET-T from PNET-NT (AUC = 0.89; sensitivity = 0.85; specificity = 0.92) and a cutoff of 1.49 m/s differentiated pancreatic tissue of CTR from PNET-T (AUC = 0.96; sensitivity = 0.92; specificity = 1.00). The SWS of PNET-T was positively correlated with PET derived asphericity (r = 0.81; p = 0.01). CONCLUSIONS: Tomoelastography provides quantitative imaging markers for the detection of PNET and the prediction of greater tumor aggressiveness by increased stiffness.

Tomoelastography for Measurement of Tumor Volume Related to Tissue Stiffness in Pancreatic Ductal Adenocarcinomas.

OBJECTIVES: Estimations of tumor volume and boundary in pancreatic ductal adenocarcinoma (PDAC) are crucial for surgery planning. The aim of the study is to evaluate tomoelastography for detection of PDAC and quantification of PDAC volume based on tissue stiffness. MATERIALS AND METHODS: From March 2018 to December 2019, a total of 102 participants (30 healthy participants and 72 patients with histologically proven PDAC) were prospectively enrolled in a multicenter study. Multifrequency magnetic resonance elastography was combined with tomoelastography postprocessing to generate maps of shear wave speed (SWS) depicting highly resolved anatomical details of tissue stiffness. Subregional analysis of pancreatic head, body, and tail and reproducibility tests were performed in healthy participants, whereas tumorous (PDAC-T) and nontumorous (PDAC-NT) pancreatic tissue analysis was conducted in patients. In all patients, tumor volumes measured by computed tomography (CT) were compared with SWS-derived volumes. In addition, in 32 patients, tumor sizes were evaluated by macroscopy after resection. RESULTS: Tumor volumes were quantified in 99% and 87% of all cases with tomoelastography and CT, respectively. Pancreatic SWS was highly reproducible (repeatability coefficient = 0.12) and did not vary regionally or with patient age, sex, or body mass index (all P > 0.08). Shear wave speed was higher in PDAC-T (2.08 ± 0.38 m/s) than in healthy (1.25 ± 0.09 m/s; P < 0.001) and PDAC-NT (1.28 ± 0.14 m/s; P < 0.001) participants. A threshold of 1.47 m/s separated PDAC-T from healthy volunteers (area under the curve = 1.0, sensitivity = 100%, specificity = 100%), while 1.49 m/s separated PDAC-T from PDAC-NT with high accuracy (area under the curve = 0.99, sensitivity = 90%, specificity = 100%). Tomoelastography-derived tumor volume correlated with CT volume (r = 0.91, P < 0.001) and ex vivo tumor volume (r = 0.66, P < 0.001). CONCLUSIONS: Tomoelastography provides a quantitative imaging marker for tissue stiffness depicting PDAC boundaries and separates PDAC from unaffected pancreatic tissue.

Antegrade stent placement in laparoscopic upper urinary tract surgery. Is there an easy way?

INTRODUCTION: Antegrade placement of double J stents in laparoscopy is considered a challenging and time-consuming process due to limitations regarding stent flexibility. AIM: To describe the method we used to facilitate the antegrade placement of intracorporeal stents in laparoscopic upper urinary tract (LUUT) surgery and report its results. MATERIAL AND METHODS: Data obtained from 42 consecutive patients who had stents placed antegradely in laparoscopic pyeloplasty or in laparoscopic ureterolithotomy for middle-upper ureteral stones were retrospectively evaluated. The mean age of the patients was 30.1 ±18.6 (10 months-68 years) and 13 patients were in the paediatric age group. All patients in the paediatric age group underwent laparoscopic pyeloplasty. RESULTS: The mean operative time for the 42 total cases, of which 32 underwent laparoscopic dismembered pyeloplasty and 10 laparoscopic ureterolithotomy, was 126.9 ±33.5 (70-200) min and the intraoperative stent placement time was calculated as 2.61 ±0.8 (1.5-5) min. The patients, who had a mean hospitalization time of 2.8 ±0.9 (2-5) months, required no additional interventions and no complications were encountered intraoperatively. In the patient series that had a mean follow-up time of 17.4 ±11.3 (1-35), it was determined only in 1 patient that the distal tip of the stent had not been in the bladder. CONCLUSIONS: The described modified antegrade stent placement technique is a practical method that is safe for all LUUT cases in both paediatric and adult age groups and it has been shown to produce successful outcomes and to be time-saving.

Can routine peripheral blood counts like neutrophil-to-lymphocyte ratio be beneficial in prediagnosis of testicular cancer and its stages?

BACKGROUND: The purpose of this study was to assess the diagnostic role of preoperative hematological parameters, especially neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) in germ cell testicular malignancies and their prediagnostic role in staging of testicular cancer. MATERIALS AND METHODS: In this cross-sectional retrospective study, we analyzed 39 patients who underwent radical orchiectomy due to a testicular cancer (Group 1) and 82 patients on whom varicocelectomy procedure was performed as control group (Group 2) between January 2006 and January 2016 in our clinic. Evaluation of the preoperative hematological parameters in both groups and also the subgroups in malignancy group according to histopathological stages was conducted in this study. RESULTS: When the hematological parameters were compared, a statistically significant difference was found between the two groups in terms of neutrophil counts, NLR, PLR, and MPV. NLR and PLR were significantly higher and MPV was significantly lower in testicular cancer group compared to the control group. NLR was 3.1 ± 1.4 and 2.0 ± 1.5, PLR was 141.3 ± 53.2 and 115.7 ± 44.8, and MPV was 8.9 ± 1.0 and 9.3 ± 1.1 for testicular cancer and control groups, respectively (P < 0.05). Furthermore, differences were observed between only mean corpuscular volume, mean corpuscular hemoglobin, and MPV (P < 0.05) in different stages of malignancy. CONCLUSION: In accordance with these findings, NLR, PLR, and MPV may be helpful for prediagnosis of testicular malignancies. Hematological parameters will become important in the preoperative assessment for those patients.

The Effect of Local Anesthetic Agent Infiltration Around Nephrostomy Tract On Postoperative Pain Control After Percutaneous Nephrolithotomy: A single-centre, randomised, double-blind, placebocontrolled clinical trial.

PURPOSE: Insufficient alleviation of pain after percutaneous nephrolithotomy causes patient dissatisfaction and generates additional morbidity factors by preventing early mobilization. This study investigated the effects of bupivacaine infiltration with two different doses around the nephrostomy tract after percutaneous nephrolithotomy. MATERIALS AND METHODS: Patients who underwent subcostal single entrance percutaneous nephrolithotomy were randomly divided into 3 groups of 20 patients. While the first and second group were planned to receive bupivacaine at rates of 0.5% and 0.25% respectively, the third group was planned to receive a placebo agent to preserve the doubly blinded nature of the study. RESULTS: A statistically significant difference was found in the number of patients using tramadole. The frequency of analgesic administration was found lower in the two groups that received bupivacaine in comparison to the group that did not, while the time of the first analgesic administration in the group that received high dose bupivacaine was significantly later than the other groups. Although there was no difference between the groups in terms of total amount of analgesic usage, patients who received higher concentrations of bupivacaine were likely to requirea lower amount of narcotic agent. The frequency of analgesic administration decreased significantly in patients of both groups that received bupivacaine. Moreover, by administering bupivacaine at a 0.5% rate, fewer patients (50%) required narcotic analgesia and the first time of analgesic administration was found to be significantly later. CONCLUSION: Administering bupivacaine at a 0.5% rate around the nephrostomy tract after surgery was demonstrated to be more effective.

Laparoscopic dismembered pyeloplasty combined with port entrance flexible renoscopic lithotripsy.

INTRODUCTION: Ureteropelvic junction obstruction and concomitant calculus disease may coexist. We demonstrate our use of flexible renoscopy during laparoscopic pyeloplasty for caliceal stone removal. PATIENT AND METHODS: A 28-year-old female patient presented with recurrent attacks of flank pain of two years duration. When noncontrast-CT and DTPA were performed, the patient was diagnosed with ureteropelvic junction stenosis and 3 stones with a total burden of 14mm in the lower pole of right kidney. After pneumoperitoneum was established in right flank position, three 10mm trocars were placed including one camera port. 5mm trocar was placed for convenience to retraction and dissection. The surgery was uneventful, with no operative complications or evidence of intra-abdominal bleeding. RESULTS: The duration of the surgery was 110 minutes. The amount of bleeding was 30ml. On the postoperative 2nd day, the urethral catheter was removed and the patient was discharged on the fourth day postoperatively. Stent removal was done on the 3rd postoperative week and retrograde pyelogram showed normal ureter. Post-operative follow-up with ultrasound showed that hydronephrosis had regressed. Conclusions: Laparoscopic pyeloplasty and concomitant flexible renoscopy through lowermost trocar with basket extraction is a simple, attractive alternative for the simultaneous treatment of ureteropelvic junction obstruction presenting with coexisting nephrolithiasis. This method is useful and feasible, with minimal invasiveness and an early post-operative recovery.

Multifrequency Magnetic Resonance Elastography for the Assessment of Renal Allograft Function.

OBJECTIVE: The aim of this study was to apply multifrequency magnetic resonance elastography (MMRE) for assessment of kidney function based on renal stiffness of allografts in transplant recipients and native kidneys in controls. METHODS: In this prospective study, MMRE was used to measure stiffness in transplant kidneys in 22 recipients (age range, 23-73 years; 7 females) and in native kidneys in 11 controls (age range, 26-55 years; 4 females) after internal review board approval. The MMRE was performed on a 1.5 T magnetic resonance imaging scanner using 4 vibration frequencies from 40 to 70 Hz. Stiffness maps were computed by multifrequency reconstruction of the magnitude shear modulus (|G*|). Clinical markers such as glomerular filtration rate (GFR) and resistive index (RI) were acquired. Differences in renal stiffness among groups were compared by Mann-Whitney U test. Correlations were tested using Pearson correlation. RESULTS: Functioning transplants had higher stiffness (|G*| = 9.00 ± 1.71 kPa) than nonfunctioning transplants (|G*| = 5.88 ± 1.71 kPa, P < 0.001) and native kidneys (|G*| = 6.63 ± 1.63 kPa, P < 0.01). A cutoff value of 7.04 kPa provided sensitivity (83.33%) and specificity (86.67%) for detecting renal allograft dysfunction with an area under the receiver operating characteristic curve value of 0.9278 (95% confidence interval, 0.83-1.00). |G*| correlated positively with GFR (r = 0.52, P = 0.015) and negatively with RI (r = -0.52, P = 0.016). CONCLUSIONS: Multifrequency magnetic resonance elastography has good diagnostic accuracy in detecting renal allograft dysfunction. Renal stiffness is significantly lower in recipients with nonfunctioning transplant kidneys and correlates with clinical markers such as GFR and RI.

Giant malignant pheochromocytoma with palpable rib metastases.

Pheochromocytoma is a rare and usually benign neuroendocrine neoplasm. Only 10% of all these tumors are malignant and there are no definitive histological or cytological criteria of malignancy. Single malignancy criteria are the presence of advanced locoregional disease or metastases. We report a case, with a giant retroperitoneal tumor having multiple metastases including palpable rib metastases, who was diagnosed as a malignant pheochromocytoma. The patient was treated with surgery. The literature was reviewed to evaluate tumor features and current diagnostic and therapeutic approaches for patients with metastatic or potentially malignant pheochromocytoma.

In-vitro effects of PDE5 inhibitor and statin treatment on the contractile responses of experimental MetS rabbit's cavernous smooth muscle.

OBJECTIVE: Hypercholesterolaemia promotes erectile dysfunction through increased superoxide formation and decreased nitric oxide bioactivity in cavernosal tissue. The role of nitric oxide on erectile function is well known. Statins have lipid lowering properties and can modulate endothelial nitric oxide bioavailability. Sildenafil, enhances smooth muscle relaxation in corpus cavernosum. We investigated in-vitro effects of sildenafil and rosuvastatin on nonadrenergic, non-cholinergic and nitric oxide mediated cavernosal smooth muscle relaxation in metabolic syndrome rabbits, since alterations in this pathway are recognised in diabetic and hypercholesterolemic erectile dysfunction. METHODS: Ten male rabbits were fed a standard diet as control group, fourty male rabbits were fed a hypercholesterolemic diet for 12 weeks. Hypercholesterolemic group were divided for without treatment, rosuvastatin treatment, sildenafil treatment, and rosuvastatin + sildenafil treatment (N = 10 per groups). RESULTS: Serum levels of cholesterol and glucose were significantly higher in the experimental group than in the control group (p < 0.05). After therapy no differences were found among the groups in relaxation responses to sodium nitroprusside. The relaxation responses to carbachol and EFS were significantly reduced in metabolic syndrome group to control group (p < 0.05), but there were no differences between the other groups and control group. There was a significantly lower in-vitro relaxation response in the metabolic syndrome rabbits than in controls and the others (p < 0.05). CONCLUSION: Both agents improve in-vitro relaxation responses of erectile tissue from metabolic syndrome rabbits to endothelial non-adrenergic, non-cholinergic and nitric oxide. This finding supports to the results of other clinical studies with these drugs.

Effect of Strontium Chloride on Experimental Bladder Inflammation in Rat.

Introduction. Strontium salts are anti-irritants for chemically induced sensory irritation. Interstitial cystitis is a painful disease without definitive therapy. The aim of the study was to determine the effect of strontium in bladder with experimental interstitial cystitis model. Material and Methods. Rats' bladders in control group were instilled with NaCl. Second group was instilled with E. coli LPS. Third group was instilled with strontium. Fourth group was initially instilled with strontium and then LPS. Fifth group was instilled with LPS initially and then strontium. Urine of rats was collected at the beginning and end of the study. Results. Histamine and TNF-α changes were statistically significant in the second group but were not significant in the third group. When we compared the histamine levels of second via fourth and fifth groups the changes were statistically not significant. When we compared the TNF-α levels of second via fourth and fifth groups the changes were statistically significant. Conclusions. In our model, strontium did not make any significant changes in histopathology or histamine levels; however, it significantly reduced the levels of TNF-α. Given the role of TNF-α in the physiopathology of interstitial cystitis, these results suggested that further studies are required to evaluate the potential use of strontium in the management of interstitial cystitis.

Relation of microvessel density with microvascular invasion, metastasis and prognosis in renal cell carcinoma.

OBJECTIVE: To clarify the significance of microvessel density (MVD) in a retrospective investigation the relationship between the pattern of MVD (reflecting angiogenesis), and tumour stage, grade, size, and occurrence of microvessel invasion (MVI), metastasis, and cancer-specific survival (CSS) in patients who had surgery for renal cell carcinoma (RCC). PATIENTS AND METHODS: Vessels were labelled in sections of formalin-fixed, paraffin-embedded tissues from 54 RCCs by CD34 immunohistochemistry. The mean MVD, expressed as the number of vessels per 10 high-power fields (HPF, x400) were measured for each case. In addition, all pathological slides were reviewed for the presence and absence of MVI. The prognostic value of MVD and MVI was then evaluated, and correlated with the usual prognostic variables, tumour metastasis and CSS. RESULTS: In a univariate analysis of CSS, the MDV tended to be lower as stage increased from pT1 to pT3, and as grade increased from G1 to G4, although it was statistically significant only for stage (P < 0.001 and 0.050, respectively). The mean MVD was higher in 42 nonmetastatic than in 12 metastatic tumours, and in 33 tumours associated with MVI than in 21 with no MVI (P < 0.001). The mean MVD was also lower and significantly different for 28 large than 26 small tumours (P = 0.005). The survival rate of patients with tumours that were small, low-stage, of higher MVD, with no MVI and metastasis was significantly higher than that of patients with large, high-stage, low MVD, with MVI and metastatic tumours (all P < 0.001). MVI was significantly more common with a decreasing trend in MVD and the presence of metastasis (Spearman rank correlation r(s) = -0.68, P = 0.01, and r(s) = 0.39, P = 0.01, respectively). Independent prognostic factors in a multivariate analysis were: in all patients with RCC, tumour stage (P = 0.013) and metastasis (P = 0.028); in those with low MVD, MVI (P = 0.004) and metastases (P = 0.016); in those with no MVI, stage (P = 0.020); in those with MVI, MVD (P = 0.001); in those with no metastases, stage (P = 0.045); and in those with metastases, MVD (P < 0.001). No independent predictor was identified in patients with high MVD. In patients with no metastases there was a significantly shorter median CSS time in RCCs with low MVD and with MVI (P = 0.004 for both). Similarly, patients who had grade 3-4 tumours, vs those with lower MVD and with MVI, had a significantly shorter median CSS (P = 0.020 for MVD, and 0.01 for MVI). CONCLUSIONS: This study suggested that MVD in RCC was inversely associated with MVI, tumour metastasis, patient survival and tumour diameter and stage, from the usual prognostic variables, but MVD was not an independent prognostic factor in multivariate analysis for all patients with RCC. Low MVD and the presence of MVI appears to be a marker for identifying patients with an adverse prognosis.

Case report: Nonobstructive giant urethral stone with two safety pins.

The urethra can be the site of various types of foreign bodies. A 61-year-old man having a giant urethral stone with two safety pins was evaluated according to the literature. To our knowledge, we report the first case of foreign bodies in urethra in which existing non-obstructive giant urethral stone with two safety pins.

Epidermoid cyst in the renal pelvis.

Epidermoid cysts are benign cysts localizing rarely in solid organs with an unclear pathogenesis. A 55 years old woman having an epidermoid cyst in the renal pelvis was evaluated according to the literature.