Plasma endothelin concentrations in patients with pulmonary hypertension associated with congenital heart defects. Evidence for increased production of endothelin in pulmonary circulation

BACKGROUND

To elucidate the pathophysiological significance of endothelin in pulmonary hypertension associated with congenital heart defects, we measured plasma endothelin-like immunoreactivity (ET-LI) concentrations by using radioimmunoassay in 18 patients with pulmonary hypertension (PH group; age, 6 months to 12 years) in comparison with 27 patients without pulmonary hypertension (non-PH group; age, 6 months to 12 years).

METHODS AND RESULTS

Blood samples were obtained from the vena cava, right atrium, right ventricle, left or right pulmonary artery, and pulmonary vein or the pulmonary arterial wedge position (pulmonary venous blood) during cardiac catheterization. Plasma ET-LI concentrations in the PH group were significantly higher than those in the non-PH group at all sampling sites. In the PH group, plasma ET-LI concentration showed a significant increase between the right ventricle and pulmonary artery and between the pulmonary artery and pulmonary vein. The increment of plasma ET-LI concentrations from the right ventricle to the pulmonary vein was significantly larger in the PH group than in the non-PH group and was significantly correlated with pulmonary artery pressure.

CONCLUSIONS

Plasma ET-LI concentrations were elevated in patients with pulmonary hypertension; the elevation was due to the increased production of ET-LI in pulmonary circulation, indicating the possible involvement of endothelin in the pathophysiology of pulmonary hypertension.

Long-term outcome of living related liver transplantation for patients with intrapulmonary shunting and strategy for complications

BACKGROUND

In 320 living related liver transplantation performed between June 1990 and September 1997, there were 21 living related liver transplantation for patients with intrapulmonary shunting, manifested by digital clubbing, cyanosis, and dyspnea. We report the long-term outcome for more 6 months and our strategy to overcome complications in these recipients.

PATIENTS

A total of 21 patients (age range 2-33 years, 19 children and 2 adults, 6 males and 15 females) were classified into three grades according to shunt ratio calculated by TcMAA pulmonary scintigraphy; 5 in mild group (shunt ratio: less than 20%), 6 in moderated group (20%-40%), and 10 in severe group (more than 40%). The original underlying liver disease was biliary atresia in all patients.

RESULTS

Spearmen's correlation coefficient rank test revealed that shunt ratio correlated significantly with PaO2 in room air (P=0.0001), PaO2 in 100% oxygen (P=0.0004), hematocrit (P=0.0276), and period of dyspnea before transplantation (P=0.023).

COMPLICATIONS

Wound infection occurred in 80, 66, and 80%, and bile leakage in 20, 0, 40% in mild, moderate, and severe group, respectively. Patients who had portal vein thrombosis, and intracranial complication were classified as severe group and the incidence was 20 and 20%, respectively. The patient actuarial one year survival was 80, 66.7, and 48%, in mild, moderate, and severe group, respectively, although there was no significant difference. All patients who survived improved hepatopulmonary syndrome and the length of period required for the resolution was significantly correlated to the preoperative shunt ratio (P=0.023).

COMMENTS

Patients with severe shunting are susceptible to wound infection and bile leak. The trend of higher incidence of portal thrombosis and intracranial complications in the severe group was closely related high hematocrit. Secure surgical technique to reduce bile leak and delayed primary wound closure to reduce wound infection were found to be effective. Anticoagulant therapy by infusing heparin through the portal vein followed by coumadin could prevent fatal portal vein thrombosis without counter risk of fatal cerebral hemorrhage.

Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth

The aim of the present study is to establish the normal range and to determine the developmental changes of plasma brain natriuretic peptide (BNP) concentrations in children. We measured plasma BNP concentrations as well as atrial natriuretic peptide (ANP) concentrations in 58 healthy children from birth to adolescence and in the umbilical vein of 20 healthy neonates using highly sensitive immunoradiometric assays. The plasma BNP concentration was the highest at 0 days of age and descended through maturation to be almost constant and to be at the adult level at 3 months of age. The plasma BNP concentration at 0 days of age (56.7 +/- 49.6 fmol/ml; mean +/- SD) was 25 to 30 times higher than the adult level and 21 times higher than that in the umbilical vein (2.7 +/- 1.4 fmol/ml). The plasma ANP concentration at 0 days of age was not significantly different from that in the umbilical vein. The ratio of BNP to ANP was also the highest at 0 days of age (1.39 +/- 0.72) and decreased through maturation to be at the adult level at 3 months of age. Thus, the plasma BNP concentration in healthy subjects showed a marked, rapid and preferential increase immediately after birth, suggesting that BNP has a physiological role distinct from that of ANP in the perinatal circulatory changes from fetus to neonate.

Dichotic listening in patients with situs inversus: brain asymmetry and situs asymmetry

In order to investigate the relation between situs asymmetry and functional asymmetry of the human brain, a consonant-vowel syllable dichotic listening test known as the Standard Dichotic Listening Test (SDLT) was administered to nine subjects with situs inversus (SI) that ranged in age from 6 to 46 years old (mean of 21.8 years old, S.D. = 15.6); the four males and five females all exhibited strong right-handedness. The SDLT was also used to study twenty four age-matched normal subjects that were from 6 to 48 years old (mean 21.7 years old, S.D. = 15.3); the twelve males and twelve females were all strongly right-handed and served as a control group. Eight out of the nine subjects (88.9%) with SI more often reproduced the sounds from the right ear than sounds from the left ear; this is called right ear advantage (REA). The ratio of REA in the control group was almost the same, i.e., nineteen out of the twenty-four subjects (79.1%) showed REA. Results of the present study suggest that the left-right reversal in situs inversus does not involve functional asymmetry of the brain. As such, the system that produces functional asymmetry in the human brain must independently recognize laterality from situs asymmetry.

Plasma levels of adrenomedullin in primary and secondary pulmonary hypertension in patients <20 years of age

To elucidate the pathophysiologic significance of adrenomedullin in pulmonary hypertension, we measured plasma adrenomedullin-like immunoreactivity (AM-LI) concentrations in blood samples obtained from various sites during cardiac catheterization by using radioimmunoassay in patients with pulmonary hypertension in comparison with patients without pulmonary hypertension. In patients with pulmonary hypertension, plasma AM-LI concentrations were significantly elevated and there was a significant uptake of AM-LI in pulmonary circulation, indicating the involvement of adrenomedullin in the cardiovascular regulation of pulmonary circulation in pulmonary hypertension.

Tacrolimus and myocardial hypertrophy

Tacrolimus has been used as an immunosuppressive agent in the transplantation of all solid organs. Tacrolimus-induced hypertrophic cardiomyopathy has been reported to be an unusual but serious complication. To elucidate the effects of tacrolimus on myocardial hypertrophy, we studied the relationship between the blood levels of tacrolimus and cardiac wall thickening. Our findings demonstrated that tacrolimus-induced myocardial hypertrophy correlated with tacrolimus blood levels, and that myocardial hypertrophy induced by tacrolimus was reversible. However, no patients developed clinically significant symptoms related to myocardial hypertrophy.

Plasma endothelin levels in healthy children: high values in early infancy

We measured plasma endothelin-1-like immunoreactivity (ET-1-LI) levels in the peripheral vein of 70 healthy children (37 males and 33 females) aged 5 days to 15 years to establish the normal range in children, and compared them with those in 11 normal adults (age, mean +/- SD; 29.5 +/- 5.7 years, 6 males and 5 females). Plasma ET-1-LI levels (pg/ml, mean +/- SD) in children of each age group and adults were as follows: children younger than 1 month = 23.4 +/- 3.9 (n = 10), 1-3 months = 25.0 +/- 6.1 (n = 8), 3-6 months = 17.0 +/- 1.4 (n = 8), 6 months to 1 year = 14.0 +/- 1.7 (n = 13), 1-5 years = 13.8 +/- 2.6 (n = 11), 5-10 years = 13.6 +/- 1.6 (n = 10), 10-15 years = 12.9 +/- 2.2 (n = 10), and adults = 13.2 +/- 2.4 (n = 11). There was no significant difference in plasma ET-1-LI levels between males and females in each age group. Plasma ET-1-LI levels in children younger than 3 months were significantly (p less than 0.01) higher than those in older children or adults. After 3 months of age, plasma ET-1-LI levels were nearly constant at all ages. This is the first report to establish the normal range of plasma ET-1-LI levels in children.

Protective role of podocyte autophagy against glomerular endothelial dysfunction in diabetes

To examine the cell-protective role of podocyte autophagy against glomerular endothelial dysfunction in diabetes, we analyzed the renal phenotype of tamoxifen (TM)-inducible podocyte-specific Atg5-deficient (iPodo-Atg5^-/-) mice with experimental endothelial dysfunction. In both control and iPodo-Atg5^-/- mice, high fat diet (HFD) feeding induced glomerular endothelial damage characterized by decreased urinary nitric oxide (NO) excretion, collapsed endothelial fenestrae, and reduced endothelial glycocalyx. HFD-fed control mice showed slight albuminuria and nearly normal podocyte morphology. In contrast, HFD-fed iPodo-Atg5^-/- mice developed massive albuminuria accompanied by severe podocyte injury that was observed predominantly in podocytes adjacent to damaged endothelial cells by scanning electron microscopy. Although podocyte-specific autophagy deficiency did not affect endothelial NO synthase deficiency-associated albuminuria, it markedly exacerbated albuminuria and severe podocyte morphological damage when the damage was induced by intravenous neuraminidase injection to remove glycocalyx from the endothelial surface. Furthermore, endoplasmic reticulum stress was accelerated in podocytes of iPodo-Atg5^-/- mice stimulated with neuraminidase, and treatment with molecular chaperone tauroursodeoxycholic acid improved neuraminidase-induced severe albuminuria and podocyte injury. In conclusion, podocyte autophagy plays a renoprotective role against diabetes-related structural endothelial damage, providing an additional insight into the pathogenesis of massive proteinuria in diabetic nephropathy.

Age-related acute adriamycin cardiotoxicity in mice

Myocardial mitochondrial function after acute adriamycin exposure was compared in infant and adult mice. Heart mitochondrial were isolated 48 h after an intraperitoneal injection of adriamycin. Concentrations of adriamycin in serum and heart tissue were not significantly different between infant and adult mice. Oxygen consumption (state 3 respiration), and respiratory control ratio (RCR) were studied polarographically. Enzyme activities in the respiratory chain [succinate-cytochrome c reductase (SCCR), NADH-cytochrome c reductase (NCCR), cytochrome c oxidase (CCO)], and adenine nucleotide translocase (ANT) were assayed. After saline injection (control), no significant differences were detected in state 3 respiration, RCR, and enzyme activity of ANT between infant and adult mice. The respective enzyme activities of SCCR, NCCR, and CCO in adult mice were significantly lower than those in infant mice. After adriamycin injection in adult mice, there were significant decreases in state 3 respiration (using glutamate and malate as substrates from 239 +/- 25 to 160 +/- 50 nanoatom O2/min/mg protein), RCR (using glutamate and malate as substrates from 7.2 +/- 1.0 to 4.4 +/- 1.4), and enzyme activities of SCCR (from 279 +/- 30 to 178 +/- 28 nmol/min/mg protein) and NCCR (from 331 +/- 43 to 237 +/- 30 nmol/min/mg protein), but there were no significant changes in infant mice. No significant changes in enzyme activities of CCO and ANT were found in either infant or adult mice following the administration of adriamycin. In conclusion, adriamycin is less toxic on the myocardial mitochondrial function in infant mice than in adult mice.

Regional myocardial perfusion and metabolism assessed by positron emission tomography in children with Kawasaki disease and significance of abnormal Q waves and their disappearance

To clarify the significance of newly appearing abnormal Q waves and their disappearance in patients with Kawasaki disease, regional myocardial perfusion and glucose metabolism at rest in the fasting condition were assessed by positron emission tomography (PET) with 13N-ammonia and 18F-fluorodeoxyglucose (FDG), and regional wall motion by left ventriculography in regions with persistent and transient abnormal Q waves in 14 patients. PET identified 3 groups of abnormal myocardial segments: segments with hypoperfusion without increased FDG uptake, those with hypoperfusion and increased FDG uptake, and those with normal perfusion and increased FDG uptake. Almost all the segments with persistent or transient abnormal Q waves had abnormal PET findings. PET demonstrated evidence of metabolic activity in 57% of segments with persistent abnormal Q waves and 67% of those with transient abnormal Q waves. Regional wall motion, scored from 0 (normal) to 4 (dyskinesia), was not significantly different between segments with persistent and transient abnormal Q waves (2.3 +/- 1.3 vs 2.2 +/- 1.2). The persistence of abnormal Q waves on serial electrocardiograms was significantly shorter in metabolically active than in inactive segments (19 +/- 17 vs 92 +/- 27 months). In conclusion, in patients with Kawasaki disease, the new appearance of abnormal Q waves is a reliable clue to the presence of ischemic myocardial injury and a high proportion of them are associated with metabolically active myocardial regions. The disappearance of abnormal Q waves does not necessarily mean the normalization of regional myocardial perfusion, metabolism or function, and their early disappearance may imply "viability" in the associated myocardial region.

Intrapulmonary shunting in biliary atresia before and after living-related liver transplantation

BACKGROUND

Intrapulmonary shunting (IPS) is frequently observed and causes hypoxaemia in liver cirrhosis. This study investigated the prevalence, predictors of reversibility and the effect of living-related liver transplantation (LRLT) on IPS using contrast echocardiography in patients with end-stage biliary atresia.

METHODS

Fifty consecutive patients with biliary atresia were examined for IPS using contrast echocardiography before and after LRLT until IPS disappeared. The severity of IPS was classified into five grades according to the extent of contrast in the left ventricle (0, none; 1, trivial; 2, apparent; 3, complete but less than in right ventricle; 4, as dense as in right ventricle).

RESULTS

Thirty-two patients (grade 1, n = 15; grade 2, n = 7; grade 3, n = 4; grade 4, n = 6) had IPS before LRLT. Forty-four patients have survived for 9-26 months after LRLT. Among patients with grade 3 or 4 IPS (n = 8), there was a significant correlation between age at LRLT and the duration of IPS persistence after LRLT (P = 0.044).

CONCLUSION

IPS takes longer to disappear in older children than in younger ones, but always disappears eventually. LRLT is an effective treatment for biliary atresia with IPS. Presented to the 31st annual meeting of the Pacific Association of Pediatric Surgeons, Maui, Hawaii, June 1998

Significant regional heterogeneity of coronary flow reserve in paediatric hypertrophic cardiomyopathy

Previous studies have indicated that cardiac events in young patients with hypertrophic cardiomyopathy (HCM) are related to ischaemia rather than to arrhythmia. We measured coronary flow reserve in paediatric HCM and compared the values with those in adult HCM. We studied 12 patients with HCM including six paediatric (<20 years old; mean 13 years) and six adult patients (>20 years old: mean 62 years), and six healthy young adults (mean 29 years) as controls. Every patient underwent magnetic resonance imaging (MRI) for anatomical assessment. Myocardial blood flow at rest and after dipyridamole infusion was measured with dynamic nitrogen-13 ammonia positron emission tomography (PET). Partial volume effect was corrected for using the anatomical data obtained with MRI. In adult patients with HCM, coronary flow reserve in the hypertrophied septal region was not significantly different from that in the non-hypertrophied lateral wall (1.38+/-0.29 vs 1.77+/-0.39, respectively). In the paediatric patients, coronary flow reserve in the hypertrophied septal region was significantly lower than in the non-hypertrophied lateral wall (0.84+/-0.33 vs 2.74+/-0.90, respectively, P<0.01). In addition, coronary flow reserve in adult patients was lower than in control subjects both in the septal wall (1.38+/-0.29 vs 2.94+/-0.35, respectively, P<0.0001) and in the lateral wall (1.77+/-0.39 vs 2.85+/-0.69, respectively, P<0.05). In contrast, coronary flow reserve in paediatric patients was not significantly different from that in control subjects in the lateral wall (2.74+/-0.90 vs 2.85+/-0.69, respectively), while absolute reduction of myocardial blood flow was noted after pharmacological vasodilatation in the hypertrophied septal region. In conclusion, significant regional differences of coronary flow reserve were present in the paediatric patients with HCM. These results suggest that paediatric patients with HCM intrinsically have the potential to experience significant regional ischaemia even in the absence of coronary stenosis.

Acute pure red cell aplasia associated with allopurinol therapy

Several investigators have reported patients with acute pure red cell aplasia (PRCA) caused by anticonvulsants, antibiotics, or antithyroid agents. Allopurinol is known to be a causative agent of aplastic anemia, but there have been few reports of acute PRCA induced by allopurinol. We describe here a 15-year-old boy who suffered from anemia 6 weeks after initiation of allopurinol therapy; his anemia immediately improved after cessation of the drug. His bone marrow showed severe erythroid hypoplasia with a myeloid/erythroid ratio of 18.6 and low expression of glycophorin A detected on cell-surface antigen analysis. No morphological abnormalities were observed in myeloid series and megakaryocytes. The prolonged plasma iron disappearance rate and the decreased plasma iron turnover rate also indicated erythroid hypoplasia. He had been free from any infections, including parvovirus B19, before manifestation of PRCA. Taken together, these results suggest a diagnosis of acute PRCA. This side effect of allopurinol should be taken into consideration.

Magnetic resonance imaging of old myocardial infarction in young patients with a history of Kawasaki disease

BACKGROUND

On magnetic resonance imaging (MRI) using gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) as contrast medium, images of infarct regions are enhanced in acute myocardial infarction (AMI). In old myocardial infarction (OMI), thinning of the myocardial walls is present, but images are no longer enhanced by Gd-DTPA. On the other hand, MI in children with a history of Kawasaki disease (KD), several differences from adult MI are observed.

HYPOTHESIS

The aim of this study was to evaluate the lesions that result from OMI in children with a history of KD using MRI with Gd-DTPA as a contrast medium.

METHODS

The subjects were 16 young patients with a history of KD who were diagnosed as having OMI. Of these, both thinning of the myocardial wall and MRI enhancement by Gd-DTPA were observed in 4 cases, thinning alone was observed in 6 cases, Gd-DTPA image enhancement alone was observed in 3 cases, and neither thinning nor Gd-DTPA image enhancement was observed in 3 cases.

RESULTS

The Gd-DTPA-image-enhanced, OMI-induced lesions observed in patients with KD were different from those observed in adults; this might be attributable to histologic differences.

CONCLUSION

Magnetic resonance imaging using Gd-DTPA can evaluate myocardial thinning and presence of circulation noninvasively at the same time and is considered to be useful for long-term follow up of the patients with KD and OMI.

Significance of dipyridamole loading in ultrafast x-ray computed tomography for detection of myocardial ischemia. A study in patients with Kawasaki disease

BACKGROUND AND RATIONALE

To examine the significance of dipyridamole loading as a stress in ultrafast computed tomography (CT) to improve the detection of left ventricular myocardial ischemia.

METHODS

Thirty-eight patients with coronary arterial involvement of Kawasaki disease and 18 control subjects received cardiac ultrafast CT with intravenous long-bolus iodinated contrast injection; dipyridamole was loaded in 40 examinations. Early (first-pass) and late (4 minutes) M/Ls (ratio of postcontrast incremental increases in the left ventricular myocardial [M] and luminal [L] CT number) were analyzed.

RESULTS

Dipyridamole induced a prominent increase in early M/L of the normal myocardium in control subjects (no loading: 26.8%, dipyridamole: 39.2%; P < 0.001) with small influence on late M/Ls. In ischemic or infarcted myocardium in Kawasaki disease, dipyridamole early M/Ls (20.4%, 16.0%) and late M/Ls showed no difference from corresponding values without loading. Using early M/L with dipyridamole, sensitivity and specificity for detection of ischemic abnormalities were 89% and 100%, respectively.

CONCLUSIONS

Dipyridamole-loaded first-pass contrast ultrafast CT was proven to have excellent detectability for myocardial ischemia comparable with stress thallium scintigraphy.

Diagnosing infection of extracardiac conduit in children

Between August 1985 and July 1992, at our center, 142 Japanese children had an extracardiac conduit operation to reconstruct the right ventricular outflow tract. The study group consisted of 22 of these 142 children who had a persistent fever and whose serum was positive for acute-phase reactants after the operation. We present the diagnostic findings for 10 children with infection of an extracardiac conduit that had been placed to restore the continuity of the right ventricle-pulmonary artery. They were part of the group of 22 children who were followed over the past 7 years with blood cultures, echocardiography, and 67Ga imaging. All 10 developed a persistent fever and were seropositive for acute-phase reactants. Conduit infection was diagnosed in only 2 patients by the detection of vegetation on echocardiography and was diagnosed in 9 of the 10 patients by an abnormal 67Ga uptake in the area of the artificial vessels used to reconstruct the pulmonary artery. The present study compared the use of blood cultures, echocardiography, and 67Ga imaging in diagnosing an infection of the extracardiac conduit. The sensitivity of blood cultures in diagnosing an extracardiac conduit infection was 70% (7/10), and the specificity was 92% (1/12). 67Ga imaging showed a higher sensitivity than echocardiography in diagnosing infection of an extracardiac conduit.

[Gallium-67 imaging in patients with myocarditis in childhood and youth]

Gallium-67 (Ga-67) myocardial imaging was performed in 19 patients (1 month to 21 years of age) with proven or suspected myocarditis. The anterior images, 48 hrs after the intravenous administration of 0.5-2.0 mCi Ga-67 citrate, were analysed using a computer. Regions of interest were set on the heart, lungs and background, excluding the sternum and vertebrae. The uptake of Ga-67 was evaluated quantitatively by the ratio of the average count of the heart to the average count of the lung (H/L). When the H/L value was higher than 130% the cardiac uptake of Ga-67 was designated positive. Histological examination was performed in 11 patients who underwent right endomyocardial biopsy. The patients were categorized according to their clinical findings. Group 1 consisted of 11 patients with clinical symptoms of dilated cardiomyopathy, six of whom had arrhythmias or elevated serum CPK-MB levels (group Ia) in the acute stage of the disease, and the remaining five had neither (group Ib). Group 2 consisted of eight patients with dysrhythmias but without heart failure. Four had elevated serum CPK-MB levels (group IIa), but the remaining four did not (group IIb). All patients in the group Ia had positive Ga-67 uptakes, and three patients in the group Ib had negative uptakes. The H/L values were significantly higher in the group Ia than in the group Ib (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Establishment of a novel mouse model of renal artery coiling-based chronic hypoperfusion-related kidney injury

Renal artery stenosis-induced chronic renal ischemia is an important cause of renal dysfunction, especially in older adults, and its incidence is currently increasing. To elucidate the mechanisms underlying chronic renal hypoperfusion-induced kidney damage, we developed a novel mouse model of renal artery coiling-based chronic hypoperfusion-related kidney injury. This model exhibits decreased renal blood flow and function, atrophy, and parenchymal injury in the coiled kidney, along with compensatory hypertrophy in the non-coiled kidney, without chronic hypertension. The availability of this mouse model, which can develop renal ischemia without genetic modification, will enhance kidney disease research by serving as a new tool to investigate the effects of acquired factors (e.g., obesity and aging) and genetic factors on renal artery stenosis-related renal parenchymal damage.

A Long-term Estimated Glomerular Filtration Rate Plot Analysis Permits the Accurate Assessment of a Decline in the Renal Function by Minimizing the Influence of Estimated Glomerular Filtration Rate Fluctuations

Objective Evaluating the rate of decline in the estimated glomerular filtration rate (eGFR) may help identify patients with occult chronic kidney disease (CKD). We herein report that eGFR fluctuation complicates the assessment of the rate of decline and propose a long-term eGFR plot analysis as a solution. Methods In 142 patients with persistent eGFR decline in a single hospital, we evaluated the factors influencing the rate of eGFR decline, calculated over the long term (≥3 years) and short term (<3 years) using eGFR plots, taking into account eGFR fluctuation between visits. Results The difference between the rate of eGFR decline calculated using short- and long-term plots increased as the time period considered in the short-term plots became shorter. A regression analysis revealed that eGFR fluctuation was the only factor that explained the difference and that the fluctuation exceeded the annual eGFR decline in all participants. Furthermore, the larger the eGFR fluctuation, the more difficult it became to detect eGFR decline using a short-term eGFR analysis. Obesity, a high eGFR at baseline, and faster eGFR decline were associated with larger eGFR fluctuations. To circumvent the issue of eGFR fluctuation in the assessment of the rate of eGFR decline, we developed a system that generates a long-term eGFR plot using all eGFR values for a participant, which enabled the detection of occult CKD, facilitating early therapeutic intervention. Conclusion The construction of long-term eGFR plots is useful for identifying patients with progressive eGFR decline, as it minimizes the effect of eGFR fluctuation.

Fructose overconsumption accelerates renal dysfunction with aberrant glomerular endothelial-mesangial cell interactions in db/db mice

For the advancement of DKD treatment, identifying unrecognized residual risk factors is essential. We explored the impact of obesity diversity derived from different carbohydrate qualities, with an emphasis on the increasing trend of excessive fructose consumption and its effect on DKD progression. In this study, we utilized db/db mice to establish a novel diabetic model characterized by fructose overconsumption, aiming to uncover the underlying mechanisms of renal damage. Compared to the control diet group, the fructose-fed db/db mice exhibited more pronounced obesity yet demonstrated milder glucose intolerance. Plasma cystatin C levels were elevated in the fructose model compared to the control, and this elevation was accompanied by enhanced glomerular sclerosis, even though albuminuria levels and tubular lesions were comparable. Single-cell RNA sequencing of the whole kidney highlighted an increase in Lrg1 in glomerular endothelial cells (GECs) in the fructose model, which appeared to drive mesangial fibrosis through enhanced TGF-β1 signaling. Our findings suggest that excessive fructose intake exacerbates diabetic kidney disease progression, mediated by aberrant Lrg1-driven crosstalk between GECs and mesangial cells.

Myocardial metabolic changes in hypertrophic cardiomyopathy

We evaluated myocardial blood flow, glucose and oxygen metabolism using PET in hypertrophic cardiomyopathy (HCM).

METHODS

PET studies using 18F-fluorodeoxyglucose (FDG) and 11C-acetate were performed at rest in patients with HCM and normal subjects as a control group. The metabolic rate of glucose (MRGlu), K mono value as a marker of oxidative metabolism, and myocardial blood flow were estimated from serial dynamic FDG and 11C-acetate PET studies.

RESULTS

Myocardial blood flow (%) did not differ significantly in hypertrophic and nonhypertrophic myocardium (90.3 +/- 3.1 versus 91.7 +/- 3.4). The MRGlu in hypertrophic myocardium, however, was lower than that of hypertrophic and normal myocardium (0.44 +/- 0.10 versus 0.52 +/- 0.15 and 0.53 +/- 0.15 mumole/min/g, respectively, p < 0.05). The K mono values were also lower in hypertrophic myocardium than in nonhypertrophic and normal myocardium (0.05 +/- 0.010 versus 0.066 +/- 0.0011 and 0.065 +/- 0.017 per min, respectively, p < 0.05). The %FDG/%perfusion values in hypertrophic myocardium did not differ significantly from those in nonhypertrophic myocardium (0.96 +/- 0.10 versus 1.02 +/- 0.07).

CONCLUSION

Myocardial ischemia at rest is observed less frequently in patients with HCM. Impairment of oxidative and glucose metabolism may precede decreased blood flow. Primary metabolic impairment is considered to be dominant in hypertrophic myocardium.