Serum VEGF-A levels on admission in COVID-19 patients correlate with SP-D and neutrophils, reflecting disease severity: A prospective study.

BACKGROUND AND OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant global morbidity and mortality. This study aimed to investigate the clinical significance of serum vascular endothelial growth factor A (VEGF-A) in COVID-19 patients and its association with disease severity and pulmonary injury. METHODS: We prospectively collected data from 71 hospitalized COVID-19 patients between June 2020 and January 2021. Patients were classified as either mild or severe based on their oxygen requirements during hospitalization. Serum VEGF-A levels were measured using an ELISA kit. RESULTS: In comparison to mild cases, significantly elevated serum VEGF-A levels were observed in severe COVID-19 patients. Furthermore, VEGF-A levels exhibited a positive correlation with white blood cell count, neutrophil count, and lymphocyte count. Notably, serum surfactant protein-D (SP-D), an indicator of alveolar epithelial cell damage, was significantly higher in patients with elevated VEGF-A levels. CONCLUSION: These results suggest that elevated serum VEGF-A levels could serve as a prognostic biomarker for COVID-19 as it is indicative of alveolar epithelial cell injury caused by SARS-CoV-2 infection. Additionally, we observed a correlation between VEGF-A and neutrophil activation, which plays a role in the immune response during endothelial cell injury, indicating a potential involvement of angiogenesis in disease progression. Further research is needed to elucidate the underlying mechanisms of VEGF-A elevation in COVID-19.

Cardiovascular risk assessments in patients with cortisol-producing adenoma: impact of clinical features and genetic characteristics.

The causes of adrenal Cushing's syndrome (CS) encompass a wide spectrum of adrenal cortisol proliferations that exhibit clinical and molecular heterogeneity. The aims of our study were to investigate whether clinical and molecular heterogeneity influences endothelial function and metabolic abnormalities in patients with cortisol-producing adenoma (CPA). We retrospectively enrolled 25 patients with CPA and 45 patients with essential hypertension (EH). All CPAs were studied by direct sequencing of PRKACA. Flow-mediated vasodilation (FMD), an index of vascular endothelial function, was significantly lower in CS and subclinical CS (SCS) groups than in the EH group. FMD impairment did not differ significantly between CS and SCS groups. No differences in FMD were seen between PRKACA mutant and wild-type groups. FMD correlated negatively with hemoglobin A1c (HbA1c) in both PRKACA mutant and wild-type groups, as well as in CS and SCS groups. After adrenalectomy, systolic blood pressure (SBP) and HbA1c decreased significantly from baseline in the CS group, and SBP and low-density lipoprotein cholesterol (LDL-C) decreased significantly from baseline in the SCS group. While SBP and LDL-C decreased significantly from baseline in patients with wild-type PRKACA, only HbA1c decreased from baseline in patients harboring PRKACA mutations. Our data showed that patients with CPA have impaired endothelial function compared with EH patients and suggest the need for strict monitoring of atherosclerosis, even in patients with SCS or without PRKACA mutation.

Characteristics of Month-by-Month Blood Pressure Variability in Patients on Hemodialysis.

INTRODUCTION: Poor prognosis in hemodialysis (HD) patients is due to the increased prevalence of cardiovascular diseases among them. We previously reported that higher visit-by-visit blood pressure variability is associated with increased cardiovascular mortality in HD patients. This present study aimed to investigate the characteristics of month-by-month blood pressure variability (MMBPV) in these patients. METHODS: A total of 324 maintenance HD patients, who could be followed up for 60 months, were recruited. We used standard deviation (SD), coefficient of variation (CV), and variation independent of the mean (VIM) in pre- and post-dialysis systolic blood pressure (pre- and post-SD, pre- and post-CV, and pre- and post-VIM) as an index of MMBPV. We investigated (1) the reproducibility of MMBPV, (2) relationship between these values and background factors, and (3) association between these values and mortality. RESULTS: MMBPV (pre- and post-SD, pre- and post-CV, and pre- and post-VIM) showed significant reproducibility (intraclass correlation, 0.483 [p < 0.001], 0.553 [p < 0.001], 0.450 [p < 0.001], 0.518 [p < 0.001], 0.456 [p < 0.001], and 0.522 [p < 0.001], respectively). High pre-VIM was associated with high interdialytic weight gain and poor nutritional status. High post-VIM was associated with glucose intolerance, high interdialytic weight gain, and poor nutritional status and associated with high rate of cardiovascular deaths independent of other factors (hazard ratio: 1.104, 95% confidence interval: 1.011-1.207, p = 0.028). CONCLUSION: These data suggested that pre- and post-VIM in HD patients are reproducible and associated with various background factors, and especially post-VIM is independently correlated with cardiovascular mortality. Further studies are necessary to confirm the mechanism of increased post-VIM and clarify whether reducing post-VIM can improve the prognosis of HD patients.

Effects of Aliskiren Monotherapy versus Amlodipine Monotherapy in Hypertensive Patients with Obesity or Type 2 Diabetes Mellitus.

INTRODUCTION: Renin-angiotensin system inhibitors have been reported to exert protective effects against organ damage and failure; however, the impact of the direct renin inhibitor as monotherapy has not been assessed. Here, we investigated the effects of 24-week monotherapy with aliskiren compared to amlodipine in hypertensive patients with type 2 diabetes or obesity. METHODS: In this randomized intervention study, 62 adult hypertensive patients with visceral obesity (defined as a body mass index [BMI] greater than 25 kg/m2 and a visceral adipose tissue area [VFA] greater than 100 cm2) or type 2 diabetes mellitus (age 57 ± 13, 65% men, BMI 28.8 ± 4.8 kg/m2, VFA 134.8 ± 47.0 cm2, blood pressure 141 ± 16/86 ± 13 mm Hg) were randomized to receive 24-week treatment with aliskiren (max. 300 mg) or amlodipine (max. 10 mg). The primary outcome was the change in VFA at 24 weeks post-treatment. RESULTS: Change in VFA did not differ significantly from baseline in either group. Systolic blood pressure significantly decreased at 12 weeks (-10 mm Hg, p = 0.001) and 24 weeks (-10 mm Hg, p = 0.001) in the amlodipine group and at 24 weeks (-11 mm Hg, p = 0.001) in the aliskiren group. Diastolic blood pressure significantly decreased at 24 weeks (-6 mm Hg, p = 0.009) only in the amlodipine group. Although the estimated glomerular filtration rates did not significantly change in either group, the logarithm of urinary albumin excretion significantly decreased at 24 weeks only in the aliskiren group (-0.60, p < 0.001). The 24-week changes in the urinary albumin excretion significantly correlated with the changes in the plasma renin activity in the aliskiren group (r = 0.51, p = 0.008). CONCLUSION: Aliskiren monotherapy did not show any superiority to amlodipine monotherapy on VFA, estimated glomerular filtration rates, or urinary albumin excretion in obese or type 2 diabetic hypertensive patients.

Impact of Abdominal Fat Distribution on Mortality and Its Changes Over Time in Patients Undergoing Hemodialysis: A Prospective Cohort Study.

OBJECTIVE: Measures of fat distribution and visceral fat accumulation maintain a direct association with mortality in the general population. However, among patients undergoing hemodialysis (HD), there are few reports of this association. This study aimed to investigate the impact of computed tomography (CT)-measured abdominal fat levels, including the visceral fat area (VFA) and subcutaneous fat area (SFA), on all-cause mortality in patients undergoing HD and investigate whether there are sex-specific particularities regarding the associations between the abovementioned parameters. METHODS: A total of 258 participants were selected from the population of patients undergoing stable HD. The baseline characteristics were collected by records and interviews. The following variables were assessed at baseline and every year: body mass index, abdominal circumference, VFA, and SFA. Abdominal circumference and body fat distribution were assessed at the level of the umbilicus via CT. All CT scans were performed on a nondialysis day with the subject in a supine position. The primary end point was the 5-year all-cause mortality. RESULTS: This prospective cohort study revealed that age, cardiothoracic ratio, %VFA (VFA/[VFA + SFA]), and albumin were independent predictors of death via multivariable analyses. Regarding the %VFA, its area under the curve (0.599), which did not suffice to predict mortality, was higher than that of VFA, SFA, and body mass index. Also, the effect was recognized mainly in male patients. The %VFA of patients who survived for 60 months increased over time. CONCLUSION: These data suggest that patients (especially men) with a high VFA-to-abdominal fat ratio have a high risk of death. Thus, more attention should be paid to such patients.

Clinical features and difficulty in diagnosis of Langerhans cell histiocytosis in the hypothalamic-pituitary region.

Langerhans cell histiocytosis (LCH) is a multi-organ disorder that rarely involves the hypothalamic-pituitary region (HPR). HPR-LCH presents with severe progressive pituitary dysfunction and its prognosis is poor. The definitive diagnosis of LCH is considerably difficult and complicated owing to the occurrence of several diseases with similar manifestations in the HPR and its location in the deepest portion of the anterior skull base, in close proximity to important normal structures, severely limiting the size of the biopsy specimen. Chemotherapy is the established treatment modality for LCH; hence, timely and accurate diagnosis of LCH is essential for early therapeutic intervention. We retrospectively reviewed clinical features and biopsy procedures in four patients with HPR-LCH (all female, 28-44 years old) from 2009 to 2020. Maximum diameter of supra-sellar lesions was 23-35 mm and 2 cases had skip lesions. All patients demonstrated central diabetes insipidus, hyper-prolactinemia, and severe anterior pituitary dysfunction. Two of the patients had progressive disease. Furthermore, four patients presented body weight gain, two visual disturbance, and two impaired consciousness. The duration from onset to diagnosis of LCH was 3 to 10 (average 7.25) years. In total, eight operations were performed until final diagnosis. The percentage of correct diagnosis by biopsy was 50% (4/8). Clinical features of HPR-LCH are very similar to those of other HPR diseases, and their symptoms are progressive and irreversible. Clinicians should consider repeated biopsy with a more aggressive approach if the lesion is refractory to steroid therapy, in order to ensure accurate diagnosis and appropriate treatment.

Adrenal cortex hypoxia modulates aldosterone production in heart failure.

Plasma aldosterone concentration increases in proportion to the severity of heart failure, even during treatment with renin-angiotensin system inhibitors. This study investigated alternative regulatory mechanisms of aldosterone production that are significant in heart failure. Dahl salt-sensitive rats on a high-salt diet, a rat model of heart failure with cardio-renal syndrome, had high plasma aldosterone levels and elevated ß3-adrenergic receptor expression in hypoxic zona glomerulosa cells. In H295R cells (a human adrenocortical cell line), hypoxia-induced ß3-adrenergic receptor expression. Hypoxia-mediated ß3-adrenergic receptor expression augmented aldosterone production by facilitating hydrolysis of lipid droplets though ERK-mediated phosphorylation of hormone-sensitive lipase, also known as cholesteryl ester hydrolase. Hypoxia also accelerated the synthesis of cholesterol esters by acyl-CoA:cholesterol acyltransferase, thereby increasing the cholesterol ester content in lipid droplets. Thus, hypoxia enhanced aldosterone production by zona glomerulosa cells via promotion of the accumulation and hydrolysis of cholesterol ester in lipid droplets. In conclusion, hypoxic zona glomerulosa cells with heart failure show enhanced aldosterone production via increased catecholamine responsiveness and activation of cholesterol trafficking, irrespective of the renin-angiotensin system.

Autopsy of malignant paraganglioma causing compressive myelopathy due to vertebral metastases.

Paraganglioma is a neuroendocrine tumor arising from extra-adrenal sites in the peripheral nervous system. Although malignant paraganglioma is known to metastasize to bones, including vertebral bodies, there is little literature on the compressive myelopathy accompanied by sphincter dysfunction; to our knowledge, only 12 cases have been reported. Moreover, neuropathological investigations of the spinal cord in this state have not been well-documented. This autopsy report describes a 55-year-old man with malignant paraganglioma and compression myelopathy caused by vertebral metastasis. The present case showed a gradual numbness and a sudden onset of irreversible paraplegia with sphincter dysfunction, which were not palliated these neurologic dysfunctions despite radiotherapy. Computed tomography (CT) revealed multiple metastases to the bones, lymph nodes, and lungs when he was diagnosed with malignant paraganglioma. At the same time, he had numbness, and magnetic resonance imaging (MRI) showed multiple diffuse metastatic lesions in the vertebral bodies. Following abrupt onset of paralysis, MRI showed fractured third and sixth thoracic vertebral bodies. An autopsy revealed residual vertebral metastases with fractures of the third and sixth thoracic vertebral bodies, resulting in compressive myelopathy at the fourth thoracic segment, which was characterized by complete spinal cord destruction. Destructive spinal cord lesion-induced secondary degeneration was observed in the gracile fasciculus at the rostral side and in the pyramidal tract at the caudal side, which showed Wallerian degeneration. Such pathology was consistent with the presenting neurological symptoms, including paraplegia and somatic sensory loss below the fourth thoracic spinal cord segment. Although it is difficult to identify the pathognomonic morphological changes responsible for the sphincter dysfunction, the present case suggests a supranuclear dysregulation of the somatosensory and central autonomic nervous systems involved in urination and defecation. Based on a review of the literature and the features of the present case, paraganglioma can metastasize aggressively even with a low pathological grading. This case of vertebral metastasis as a result of malignant paraganglioma may not be extraordinary but the autopsy report is rare. This autopsy revealed transverse myelopathy as a result of malignant vertebral metastasis of malignant paraganglioma.

Correlation between urinary fractionated metanephrines in 24-hour and spot urine samples for evaluating the therapeutic effect of metyrosine: a subanalysis of a multicenter, open-label phase I/II study.

We recently conducted an open-label phase I/II study to evaluate the efficacy and safety of preoperative and chronic treatment with metyrosine (an inhibitor of catecholamine synthesis) in pheochromocytoma/paraganglioma (PPGL) in Japan. We compared creatinine-corrected metanephrine fractions in spot urine and 24-hour urine samples (the current standard for the screening and diagnosis of PPGLs) from 16 patients to assess the therapeutic effect of metyrosine. Percent changes from baseline in urinary metanephrine (uMN) or normetanephrine (uNMN) were compared between spot and 24-hour urine samples. Mean percent changes in uMN or uNMN in spot and 24-hour urine were -26.36% and -29.27%, respectively. The difference in the percent change from baseline between uMN or uNMN in spot and 24-hour urine was small (-2.90%). The correlation coefficient was 0.87 for percent changes from baseline between uMN or uNMN measured in spot and 24-hour urine. The area under the receiver operator characteristic (ROC) curve of uMN or uNMN measured in spot urine vs. 24-hour urine (reference standard) to assess the efficacy of metyrosine treatment was 0.93. Correlations and ROCs between 24-hour urinary vanillylmandelic acid, adrenaline, and noradrenaline and 24-hour uMN or uNMN were similar to those between spot uMN or uNMN and 24-hour uMN or uNMN. No large difference was observed between spot and 24-hour urine for the assessment of metyrosine treatment by quantifying uMN or uNMN in Japanese patients with PPGLs. These results suggest that spot urine samples may be useful in assessing the therapeutic effect of metyrosine.

Fatal Fournier's gangrene caused by Clostridium ramosum in a patient with central diabetes insipidus and insulin-dependent diabetes mellitus: a case report.

BACKGROUND: Clostridium ramosum is a generally non-pathogenic enteric anaerobe, and Fournier's gangrene is a rare necrotizing soft tissue infection with male predisposition affecting the perineum and the genital area. We report, to our knowledge, the first case of Fournier's gangrene caused by C. ramosum in a female patient with multiple underlying conditions. CASE PRESENTATION: A 44-year-old woman with a 6-year history of insulin-dependent diabetes mellitus after total pancreatectomy and an 11-year history of central diabetes insipidus developed a pain in the genital area after a month of urinary catheter use. The lower abdominal pain worsened gradually over 2 weeks, and the pain, general fatigue, and loss of appetite prompted the patient's hospital admission. As she had severe edema in her pelvic and bilateral femoral areas, ceftriaxone was started empirically after collecting two sets of blood cultures. On hospital day 2, CT examination revealed the presence of necrotizing faciitis in the genital and pelvic areas, and the antibiotics were changed to a combination of meropenem, vancomycin, and clindamycin. Gram-positive cocci and gram-positive rods were isolated from blood cultures, which were finally identified as Streptococcus constellatus and C. ramosum using superoxide dismutase and 16S rDNA sequencing. An emergent surgery was performed on hospital day 2 to remove the affected tissue. Despite undergoing debridement and receiving combined antimicrobial chemotherapies, the patient's clinical improvement remained limited. The patient's condition continued to deteriorate, and she eventually died on hospital day 8. In the present case, the underlying diabetes mellitus, urinary incontinence due to central diabetes insipidus, undernutrition, and edema served as the predisposing conditions. CONCLUSIONS: C. ramosum is a potentially opportunistic pathogen among immunosuppressed persons and a rare cause of necrotizing fasciitis.

Efficacy and safety of metyrosine in pheochromocytoma/paraganglioma: a multi-center trial in Japan.

To assess the efficacy, safety, and pharmacokinetics of metyrosine (an inhibitor of catecholamine synthesis) in patients with pheochromocytoma/paraganglioma (PPGL), we conducted a prospective, multi-center, open-label study at 11 sites in Japan. We recruited PPGL patients aged ≥12 years requiring preoperative or chronic treatment, receiving α-blocker treatment, having baseline urinary metanephrine (uMN) or normetanephrine (uNMN) levels ≥3 times the upper limit of normal values, and having symptoms associated with excess catecholamine. Metyrosine treatment was started at 500 mg/day and modified according to dose-adjustment criteria up to 4,000 mg/day. The main outcome measure was the proportion of patients who achieved at least 50% reduction in uMN or uNMN levels from baseline. Sixteen patients (11 males/5 females) aged 12-86 years participated. After 12 weeks of treatment and at the last evaluation of efficacy, the primary endpoint was achieved in 31.3% of all patients, including 66.7% of those under preoperative treatment and 23.1% of those under chronic treatment. Sedation, anemia, and death were reported in 1 patient each as serious adverse drug reactions during the 24-week treatment. Metyrosine was shown to be tolerated and to relieve symptoms by reducing excess catecholamine in PPGL patients under both preoperative and chronic treatment.

The rationale and design of reduction of uncontrolled hypertension by Remote Monitoring and Telemedicine (REMOTE) study.

PURPOSE: Although self-measurement of home blood pressure (HBP) is common in Japan and HBP telemonitoring via the Internet is possible, whether telemonitoring improves HBP control better than conventional practice remains unclear. Furthermore, hypertension care with online communication using telemonitored HBP is feasible, whereas the efficacy and safety of such telemedicine have not been established. We aim to compare traditional care, care with office visits using HBP telemonitoring, and antihypertensive telemedicine based on HBP telemonitoring. METHODS AND DESIGN: In total, 444 patients with uncontrolled hypertension will be recruited and randomly assigned to three groups: (1) control: usual care with office visits and HBP self-report, (2) telemonitoring: weekly assessment of transmitted HBP by physicians and treatment adjustment upon office visits, or (3) telemedicine: online communication instead of office visits to adjust medication using telemonitored HBP. Primary outcome is the time to control of HBP, and secondary outcomes include achieved HBP levels, adherence, treatment intensity, adverse events, patient satisfaction and cost-effectiveness. DISCUSSION: Hypertension care with telemonitoring and telemedicine are expected to require shorter time to achieve HBP control compared to usual care. Combining HBP telemonitoring with telemedicine may lower the hurdles for starting and persisting to hypertension treatment and eventually reduce cardiovascular events.

Collecting duct prorenin receptor knockout reduces renal function, increases sodium excretion, and mitigates renal responses in ANG II-induced hypertensive mice.

Augmented intratubular angiotensin (ANG) II is a key determinant of enhanced distal Na+ reabsorption via activation of epithelial Na+ channels (ENaC) and other transporters, which leads to the development of high blood pressure (BP). In ANG II-induced hypertension, there is increased expression of the prorenin receptor (PRR) in the collecting duct (CD), which has been implicated in the stimulation of the sodium transporters and resultant hypertension. The impact of PRR deletion along the nephron on BP regulation and Na+ handling remains controversial. In the present study, we investigate the role of PRR in the regulation of renal function and BP by using a mouse model with specific deletion of PRR in the CD (CDPRR-KO). At basal conditions, CDPRR-KO mice had decreased renal function and lower systolic BP associated with higher fractional Na+ excretion and lower ANG II levels in urine. After 14 days of ANG II infusion (400 ng·kg-1·min-1), the increases in systolic BP and diastolic BP were mitigated in CDPRR-KO mice. CDPRR-KO mice had lower abundance of cleaved αENaC and γENaC, as well as lower ANG II and renin content in urine compared with wild-type mice. In isolated CD from CDPRR-KO mice, patch-clamp studies demonstrated that ANG II-dependent stimulation of ENaC activity was reduced because of fewer active channels and lower open probability. These data indicate that CD PRR contributes to renal function and BP responses during chronic ANG II infusion by enhancing renin activity, increasing ANG II, and activating ENaC in the distal nephron segments.

Effects of L- and N-Type Ca Channel Blocker Cilnidipine on Changes in Heart Rate and QT Interval During Dialysis.

BACKGROUND/AIMS: Hemodialysis patients have poor prognosis due to increased prevalence of cardiovascular diseases. Treatment to suppress increases in sympathetic nerve activity and QT prolongation may have the potential to reduce the occurrence of these events. The L/N-type Calcium (Ca) channel blocker cilnidipine has unique inhibitory action to inhibit sympathetic nerve activity and in a canine model ameliorates QT prolongation. In this study, we investigated whether cilnidipine has inhibitory effects on heart rate, an index of sympathetic nerve activity, and QT prolongation in patients undergoing dialysis. METHODS: An L-type Ca channel blocker amlodipine was administered for 4 weeks followed by cilnidipine treatment for 4 weeks. On the last day of each period, heart rate and corrected QT interval were estimated and compared between the two periods. RESULTS: Cilnidipine showed greater suppression of heart rate during dialysis than did amlodipine. The corrected QT interval in one dialysis session was significantly increased, and 3 of 17 patients showed prominent QT prolongation during administration of amlodipine but not cilnidipine. CONCLUSION: These data suggested that cilnidipine may inhibit increases in heart rate and QT interval. Cilnidipine may have beneficial effects in reducing cardiovascular events, resulting from increased sympathetic nerve activity and lethal arrhythmias in hemodialysis patients.

Antidiuretic Action of Collecting Duct (Pro)Renin Receptor Downstream of Vasopressin and PGE2 Receptor EP4.

Within the kidney, the (pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD), particularly in intercalated cells, and it is regulated by the PGE2 receptor EP4 Notably, EP4 also controls urinary concentration through regulation of aquaporin 2 (AQP2). Here, we tested the hypothesis that sequential activation of EP4 and PRR determines AQP2 expression in the CD, thus mediating the antidiuretic action of vasopressin (AVP). Water deprivation (WD) elevated renal PRR expression and urinary soluble PRR excretion in rats. Intrarenal infusion of a PRR decoy peptide, PRO20, or an EP4 antagonist partially prevented the decrease in urine volume and the increase in urine osmolality and AQP2 expression induced by 48-hour WD. In primary cultures of rat inner medullary CD cells, AQP2 expression induced by AVP treatment for 24 hours depended on sequential activation of the EP4 receptor and PRR. Additionally, mice lacking PRR in the CD exhibited increased urine volume and decreased urine osmolality under basal conditions and impaired urine concentrating capability accompanied by severe volume loss and a dangerous level of plasma hyperosmolality after WD. Together, these results suggest a previously undescribed linear AVP/PGE2/EP4/PRR pathway in the CD for regulation of AQP2 expression and urine concentrating capability.

Vacuolar ATPase in phagosome-lysosome fusion.

The vacuolar H(+)-ATPase (v-ATPase) complex is instrumental in establishing and maintaining acidification of some cellular compartments, thereby ensuring their functionality. Recently it has been proposed that the transmembrane V0 sector of v-ATPase and its a-subunits promote membrane fusion in the endocytic and exocytic pathways independent of their acidification functions. Here, we tested if such a proton-pumping independent role of v-ATPase also applies to phagosome-lysosome fusion. Surprisingly, endo(lyso)somes in mouse embryonic fibroblasts lacking the V0 a3 subunit of the v-ATPase acidified normally, and endosome and lysosome marker proteins were recruited to phagosomes with similar kinetics in the presence or absence of the a3 subunit. Further experiments used macrophages with a knockdown of v-ATPase accessory protein 2 (ATP6AP2) expression, resulting in a strongly reduced level of the V0 sector of the v-ATPase. However, acidification appeared undisturbed, and fusion between latex bead-containing phagosomes and lysosomes, as analyzed by electron microscopy, was even slightly enhanced, as was killing of non-pathogenic bacteria by V0 mutant macrophages. Pharmacologically neutralized lysosome pH did not affect maturation of phagosomes in mouse embryonic cells or macrophages. Finally, locking the two large parts of the v-ATPase complex together by the drug saliphenylhalamide A did not inhibit in vitro and in cellulo fusion of phagosomes with lysosomes. Hence, our data do not suggest a fusion-promoting role of the v-ATPase in the formation of phagolysosomes.

Renal tubular epithelial cell prorenin receptor regulates blood pressure and sodium transport.

The physiological significance of the renal tubular prorenin receptor (PRR) has been difficult to elucidate due to developmental abnormalities associated with global or renal-specific PRR knockout (KO). We recently developed an inducible renal tubule-wide PRR KO using the Pax8/LC1 transgenes and demonstrated that disruption of renal tubular PRR at 1 mo of age caused no renal histological abnormalities. Here, we examined the role of renal tubular PRR in blood pressure (BP) regulation and Na(+) excretion and investigated the signaling mechanisms by which PRR regulates Na(+) balance. No detectable differences in BP were observed between control and PRR KO mice fed normal- or low-Na(+) diets. However, compared with controls, PRR KO mice had elevated plasma renin concentration and lower cumulative Na(+) balance with normal- and low-Na(+) intake. PRR KO mice had an attenuated hypertensive response and reduced Na(+) retention following angiotensin II (ANG II) infusion. Furthermore, PRR KO mice had significantly lower epithelial Na(+) channel (ENaC-α) expression. Treatment with mouse prorenin increased, while PRR antagonism decreased, ENaC activity in isolated split-open collecting ducts (CD). The prorenin effect was prevented by protein kinase A and Akt inhibition, but unaffected by blockade of AT1, ERK1/2, or p38 MAPK pathways. Taken together, these data indicate that renal tubular PRR, likely via direct prorenin/renin stimulation of PKA/Akt-dependent pathways, stimulates CD ENaC activity. Absence of renal tubular PRR promotes Na(+) wasting and reduces the hypertensive response to ANG II.

Dual adrenal venous phase contrast-enhanced MDCT for visualization of right adrenal veins in patients with primary aldosteronism.

PURPOSE: To evaluate the frequency of visualization of the right adrenal vein (RAV) on dual adrenal venous phase multi-detector computed tomography (MDCT) in patients with primary aldosteronism. MATERIALS AND METHODS: Images of contrast-enhanced dual adrenal venous phase MDCT (45- and 55-second delays) in 90 patients with primary aldosteronism who underwent adrenal venous sampling were retrospectively evaluated. The degree of RAV visualization on each phase image was evaluated by two radiologists using a five-point scale and RAV visualization rates were estimated. RESULTS: The RAV visualization rates on the first- and second-phase images were 89 % and 91 % by radiologist A, and 93 % and 90 % by radiologist B, respectively. No significant differences in the score of RAV visualization were observed between the first- and second-phase images by the two readers (P = 0.164 and P = 0.06). The kappa values for inter-observer agreement of RAV visualization on the first- and second-phase images were 0.57 and 0.46, respectively. The consensual RAV visualization rates on the first- and second-phase images were 91 % and 92 %, respectively. The overall RAV visualization rate by using both phase images was 98 %. CONCLUSION: Dual adrenal venous phase MDCT can visualize the RAV in almost all patients with primary aldosteronism. KEY POINTS: • Dual adrenal venous phase MDCT images can visualize the right adrenal veins. • The adrenal venous phase lies between the arterial and portal phases. • Anatomical information will contribute to the technical success of adrenal venous sampling.

Evaluation of insulin sensitivity and secretion in primary aldosteronism.

In primary aldosteronism (PA), insulin response to glucose is not fully understood. Insulin action was elucidated using indices in 32 PA and 21 essential hypertension (EH) patients. These patients were evaluated using homeostasis model assessment (HOMA) indices, quantitative insulin sensitivity check index (QUICKI), and insulinogenic index (IGI), which were expressed for insulin sensitivity/secretion and the early phase of insulin secretion. Insulin sensitivity and early phase of insulin secretion were decreased in PA, and there was a negative correlation between serum potassium concentration and insulin sensitivity indices. These findings suggest that glucose intolerance in PA may be caused by hypokalemia-induced insulin resistance and hypokalemia-independent impairment of early-phase insulin secretion.

A functional (pro)renin receptor is expressed in human lymphocytes and monocytes.

The renin-angiotensin system (RAS) is involved in inflammation. The signaling via the ANG II type 1 receptor in human lymphocytes and monocytes, which play key roles in pathophysiology of glomerulonephritis (GN), can enhance inflammation. However, the role of the (pro)renin receptor [(P)RR], a component of the RAS, in inflammatory reactions is unknown. We assessed whether (P)RR is expressed in human lymphocytes and monocytes by RT-PCR, Western blotting, flow cytometry, and immunohistochemistry, and whether (P)RR functions in inflammation. (P)RR mRNA and protein were expressed in human peripheral blood mononuclear cells (PBMCs). Flow cytometric analysis revealed high expression of (P)RR on monocytes. (P)RR was present on PBMCs, infiltrating lymphocytes, and macrophages around glomeruli with a crescent in anti-neutrophil cytoplasmic antibody (ANCA)-associated GN. Renin stimulation of PBMCs from healthy subjects in the presence of the ANG II type 1 receptor and ANG II type 2 receptor blockers induced ERK1/2 phosphorylation and release of IL-6 and expression of cyclooxygenase-2 (COX-2). The increases in cytokine release and COX-2 expression were inhibited in the presence of an ERK1/2 inhibitor. (P)RR knockdown by small interfering RNA in U937 cells, a human leukemic monocyte lymphoma cell line, significantly decreased ERK1/2 phosphorylation after renin stimulation. Thus (P)RR expressed in human inflammatory cells might contribute to inflammation in ANCA-associated GN.