Patient-Reported Financial Toxicity Associated With Management of Nephrolithiasis

OBJECTIVE

To characterize stone-related financial burden among adults with nephrolithiasis through validated questionnaires for financial toxicity.

METHODS

We performed a cross-sectional survey of adults with history of nephrolithiasis at an outpatient clinic. The survey contained a measure of stone-related financial toxicity (COST score), and assessed demographics, stone event history, and burden of overall, ancillary, preventative, and insurance costs. A COST score ≤21 was classified as high financial toxicity. Multivariable logistic regression was used to evaluate associations with demographic variables and stone event history.

RESULTS

One hundred patients completed the survey (median age 57, IQR, 48-64). The median COST score was 30 (IQR, 23-37), and 19% reported high financial toxicity. Insurance status, household income, stone surgeries during lifetime and within the last 3 years were associated with financial toxicity on univariable analysis (P <.05). Burden of costs was significantly higher in all categories within the high financial toxicity cohort (each P <.05). On multivariable logistic regression, only income >$75,000 remained significant within the second model (OR: 0.22, 95% CI, 0.05-0.77, P = .02), however, this relationship did not persist on the final model. When asked whether providers should be mindful of their financial situation prior to making treatment recommendations, 39% responded "quite a bit" or "very much."

CONCLUSION

One in 5 patients seeking care for nephrolithiasis meet criteria for high financial toxicity. Financial toxicity was associated with household income, insurance, education, and frequency of stone events. Thirty-nine percent reported that their provider should be mindful of their financial situation when making recommendations.

The Financial Burden of Nephrolithiasis and Predictors of Disease-specific Financial Toxicity

OBJECTIVE

To characterize stone-related financial toxicity among US adults with kidney stones through validated questionnaires for financial toxicity and disease-specific health-related quality of life.

MATERIALS AND METHODS

We performed a cross-sectional survey of adults with kidney stone disease from the general population ascertained through a national registry of volunteers (ResearchMatch). A computer-based survey queried stone event history and related costs for medical care, disease-specific quality of life (WISQOL), and an 11-item measure of stone-related financial toxicity (COST-11 score). Multivariable logistic regression was performed to evaluate predictors of financial toxicity, defined as having a COST-11 score ≤20.

RESULTS

Of 942 responses, median COST-11 score was 29 (IQR 21-38), and 24.7% (N = 233) met criteria for disease-specific financial toxicity. Stone-formers with financial toxicity spent more out of pocket on stone-treatment in the previous year than patients with lower financial burden (P <.001) and were more likely to defer or delay recommended treatment due to anticipated cost (27% vs 3%; P <.001). Stone-specific financial toxicity was associated with poorer disease-specific health-related quality of life across all WISQOL domains (each P <.001). Multivariable logistic regression showed that female gender (OR 1.81; 95% CI 1.24-2.67), Medicaid compared to private insurance (OR 3.91; 95% CI 2.34-6.94), and stone passage in the previous year (OR 2.00; 95% CI 1.41-2.86) were independently associated with financial toxicity.

CONCLUSION

Approximately 1 in 4 individuals with kidney stone disease report disease-specific financial toxicity. These data suggest the financial burden of the condition may influence decision-making and associates with poorer disease-specific quality of life.

Increasing utilization of the TWIST score in workup of patients with acute scrotal pain: Role in diagnosis and risk stratification

INTRODUCTION

The TWIST score is a 5-component physical examination score used to aid in diagnosis of testicular torsion (TT) and could lessen need for radiologic testing in certain clinical scenarios.

OBJECTIVE

TWIST use was not previously widespread at our institution. The primary objective of this quality improvement study was to achieve 100% compliance in TWIST utilization among urology and ED residents and to assess for score concordance between ED and urology assessments. Secondary goals were correlation of TWIST components with need for orchiectomy.

METHODS

ED staff were educated about the TWIST score and asked to complete assessment for patients presenting with acute scrotal pain. Simultaneously, an electronic medical record-based dot phrase was introduced for urology trainees to complete an independent TWIST evaluation. Spearman correlation was performed to assess association between ED and Urology TWIST scores. Multivariable logistic regression was performed to assess association of TWIST score components and need for orchiectomy.

RESULTS

103 patients presented to the ED from 3/2018-11/2020 with a complaint of acute scrotal pain; 47 were diagnosed with torsion. As compared to our retrospective cohort, the documentation rate of complete TWIST score components on exam rose from 9% to 98% (P < 0.001) on ED evaluation and 16%-66% on urology evaluation (P < 0.001). Rates of repeat ultrasound for patient's transferred between facilities was similar (58% vs. 63%; p = 0.66) as was median time to OR (160 min vs. 145 min; p = 0.5). Using TWIST cutoff of >5 yielded a specificity of 94.5% for diagnosis of torsion, with corresponding strong correlation between ED and urology scores (rho = 0.71). A firm testicle was noted on urology evaluation in 100% of orchiectomy patients (vs. 61% of salvage patients) with persistent association after controlling for duration of symptoms (OR 28.1; P = 0.016).

DISCUSSION

Through two-pronged quality improvement efforts, we significantly improved utilization of the TWIST score by ED and urology staff for workup of patients with acute testicular pain. We confirmed the high sensitivity and specificity of the TWIST score and demonstrated inter-rater reliability between ED and urology assessments. On prospective analysis, testicular firmness on exam was predictive of need for orchiectomy.

CONCLUSION

The TWIST score is an accurate diagnostic tool for both ED and urology providers in workup of children with acute scrotal pain, with a normal score essentially ruling out the condition. Future work should aim at minimizing unnecessary testing in patients demonstrated to be at high risk for torsion.

Positive direct antiglobulin test in COVID-19 patients: Decision-making process

In this unprecedented crisis of severe acute respiratory syndrome coronavirus 2 and its associated coronavirus disease 2019 (COVID-19), polymerase chain reaction and then serological testing platforms have been massively developed to face the important screening demand. Polymerase chain reaction and serological testing platforms are not the only actors impacted by the crisis, transfusion services are facing important difficulties. A positive direct antiglobulin test is frequently observed for patients encountering COVID-19. Patients with severe symptoms may develop anaemia and become good candidates for blood transfusions. The interpretation of a positive direct antiglobulin test for patients recently transfused and suffering from COVID-19 is complex. The differentiation between COVID-19 induced antibodies and possible associated transfusion alloantibodies is therefore crucial. In this context, the elution technique incorporated in an appropriate decision-making process plays its full role. This intricate topic is presented through a case report followed by literature review and finally decision-making process for COVID-19 patients necessitating red blood cells administration.

Postoperative Opiate Use in Urological Patients: A Quality Improvement Study Aimed at Improving Opiate Disposal Practices

PURPOSE

We aimed to determine trends in postoperative opiate management among urological patients, identify associations with opiate keeping and foster appropriate opiate disposal after surgery via introduction of an educational handout.

MATERIALS AND METHODS

We retrospectively analyzed opiate practices in 68 patients who had undergone urological surgery. In a separate consecutive cohort of 59 patients we distributed a handout detailing FDA (Food and Drug Administration) approved disposal methods. Patient opiate obtainment, use and disposal were assessed via telephone interviews with prescription filling data verified using the Tennessee CSMD (Controlled Substances Monitoring Database). Opiate keeping was defined as possessing any opiates more than 3 weeks after surgery or more than 4 times the duration of the postoperative prescription, whichever was longer.

RESULTS

Opiate keeping was observed in 41 patients (72%) in our initial cohort. Of these patients 68% left the medication unsecured at home. Major barriers to opiate disposal included concern for return of disease specific pain in 44% of patients and unrelated pain in 29%. As assessed on a short test, opiate keepers were less knowledgeable about safe disposal practices compared to nonkeepers (72% vs 85%, p = 0.005). Among opiate keepers there was an improvement in knowledge scores after the intervention (66% to 77%, p = 0.03). When comparing pre-education to post-education, there was no detectable improvement in the rate of opiate keeping (72% vs 68%, p = 0.66) or proper disposal (9% vs 8%, p = 1.0).

CONCLUSIONS

Opiate keeping is common following urological surgery and a major barrier to disposal is concern for the return of disease specific pain. Future interventions aimed at limiting opiate keeping should combine evidence-based prescription practices and targeted patient education.

TRAF1 Coordinates Polyubiquitin Signaling to Enhance Epstein-Barr Virus LMP1-Mediated Growth and Survival Pathway Activation

The Epstein-Barr virus (EBV) encoded oncoprotein Latent Membrane Protein 1 (LMP1) signals through two C-terminal tail domains to drive cell growth, survival and transformation. The LMP1 membrane-proximal TES1/CTAR1 domain recruits TRAFs to activate MAP kinase, non-canonical and canonical NF-kB pathways, and is critical for EBV-mediated B-cell transformation. TRAF1 is amongst the most highly TES1-induced target genes and is abundantly expressed in EBV-associated lymphoproliferative disorders. We found that TRAF1 expression enhanced LMP1 TES1 domain-mediated activation of the p38, JNK, ERK and canonical NF-kB pathways, but not non-canonical NF-kB pathway activity. To gain insights into how TRAF1 amplifies LMP1 TES1 MAP kinase and canonical NF-kB pathways, we performed proteomic analysis of TRAF1 complexes immuno-purified from cells uninduced or induced for LMP1 TES1 signaling. Unexpectedly, we found that LMP1 TES1 domain signaling induced an association between TRAF1 and the linear ubiquitin chain assembly complex (LUBAC), and stimulated linear (M1)-linked polyubiquitin chain attachment to TRAF1 complexes. LMP1 or TRAF1 complexes isolated from EBV-transformed lymphoblastoid B cell lines (LCLs) were highly modified by M1-linked polyubiqutin chains. The M1-ubiquitin binding proteins IKK-gamma/NEMO, A20 and ABIN1 each associate with TRAF1 in cells that express LMP1. TRAF2, but not the cIAP1 or cIAP2 ubiquitin ligases, plays a key role in LUBAC recruitment and M1-chain attachment to TRAF1 complexes, implicating the TRAF1:TRAF2 heterotrimer in LMP1 TES1-dependent LUBAC activation. Depletion of either TRAF1, or the LUBAC ubiquitin E3 ligase subunit HOIP, markedly impaired LCL growth. Likewise, LMP1 or TRAF1 complexes purified from LCLs were decorated by lysine 63 (K63)-linked polyubiqutin chains. LMP1 TES1 signaling induced K63-polyubiquitin chain attachment to TRAF1 complexes, and TRAF2 was identified as K63-Ub chain target. Co-localization of M1- and K63-linked polyubiquitin chains on LMP1 complexes may facilitate downstream canonical NF-kB pathway activation. Our results highlight LUBAC as a novel potential therapeutic target in EBV-associated lymphoproliferative disorders.

The linear ubiquitin assembly complex (LUBAC) plays crucial roles in immune receptor-mediated NF-kB and MAP kinase pathway activation. Comparatively little is known about the extent to which microbial pathogens use LUBAC to activate downstream pathways. We demonstrate that TRAF1 enhances EBV oncoprotein LMP1 TES1/CTAR1 domain mediated MAP kinase and canonical NF-kB activation. LMP1 TES1 signaling induces association between TRAF1 and LUBAC, and triggers M1-polyubiquitin chain attachment to TRAF1 complexes. TRAF1 and LMP1 complexes are decorated by M1-polyubiquitin chains in LCL extracts. TRAF2 plays a key role in LMP1-induced LUBAC recruitment and M1-chain attachment to TRAF1 complexes. TRAF1 and LMP1 complexes are modified by lysine 63-linked polyubiquitin chains in LCL extracts, and TRAF2 is a target of LMP1-induced K63-ubiquitin chain attachment. Thus, the TRAF1:TRAF2 heterotrimer may coordinate ubiquitin signaling downstream of TES1. Depletion of TRAF1 or the LUBAC subunit HOIP impairs LCL growth and survival. Thus, although TRAF1 is the only TRAF without a RING finger ubiquitin ligase domain, TRAF1 nonetheless has important roles in ubiqutin-mediated signal transduction downstream of LMP1. Our work suggests that LUBAC is important for EBV-driven B-cell proliferation, and suggests that LUBAC may be a novel therapeutic target in EBV-associated lymphoproliferative disorders.

Viral pseudo-enzymes activate RIG-I via deamidation to evade cytokine production

RIG-I is a pattern recognition receptor that senses viral RNA and is crucial for host innate immune defense. Here, we describe a mechanism of RIG-I activation through amidotransferase-mediated deamidation. We show that viral homologs of phosphoribosylformylglycinamidine synthetase (PFAS), although lacking intrinsic enzyme activity, recruit cellular PFAS to deamidate and activate RIG-I. Accordingly, depletion and biochemical inhibition of PFAS impair RIG-I deamidation and concomitant activation. Purified PFAS and viral homolog thereof deamidate RIG-I in vitro. Ultimately, herpesvirus hijacks activated RIG-I to avoid antiviral cytokine production; loss of RIG-I or inhibition of RIG-I deamidation results in elevated cytokine production. Together, these findings demonstrate a surprising mechanism of RIG-I activation that is mediated by an enzyme.

Clinical and microbiological findings in prosthetic joint replacement due to aseptic loosening

OBJECTIVES

A role for microorganisms in aseptic prosthetic loosening (AL) is postulated. We analyse the microbiological and clinical findings of patients with suspected AL, and compare them with patients with chronic prosthetic joint infection (PJI).

METHODS

Prospective study (2011-2012) of patients with presumed AL. Evaluation of tissue samples (≥5; TS) at the time of surgery and sonication fluid (SF) of prosthesis.

RESULTS

According to positive culture in TS/SF, 89 patients were divided into: Group1: (≥2 positive-TS; n = 12); Group2: single positive-TS and concordant SF (n = 10); Group3: one positive or non-concordant TS or SF (n = 38); and Group4: cultures negative (n = 29). Positive-SF was always concordant with TS in Group 1 (75%); it was positive in 74% in Group 3. Median months (prosthesis-age: implantation to revision arthroplasty) for PJI and Group 1-4 was 21, 46, 65, 63 and 81, respectively (P < 0.001); they also had a different dynamic trend in prosthesis failure (P < 0.001).

CONCLUSIONS

Several patients with suspected AL are misdiagnosed PJI. Results from SF correlated well with TS in Group 1, led us to consider single positive-TS as significant (Group 2) and to suggest that microorganisms were on the prosthesis (Group 3). We observed a correlation between microbiology and prosthesis-age, which supports that early loosening is more often caused by hidden PJI than late loosening.

[Calcific myonecrosis of the leg]

Calcific myonecrosis is a rare post-traumatic sequela almost exclusively located in the lower extremity, which can be mistaken for an aggressive primary neoplasm. This lesion, initially described by Gallei and Thompson in 1960, is characterized by the formation of a calcified mass that appears decades after trauma. The pathophysiologic mechanism is not fully understood, although the lesion most likely results from post-traumatic ischemia and it may be associated with a common peroneal nerve injury. The typical radiographic image is a fusiform soft tissue mass with linear calcifications. The treatment of choice is conservative in asymptomatic patients because the surgical treatment has a high complication rate. We report four cases of calcific myonecrosis treated surgically in our hospital. Three of the cases had an infection as a complication that required subsequent debridement and special therapies to achieve the resolution of the cases.

Pilot study of ampicillin-ceftriaxone combination for treatment of orthopedic infections due to Enterococcus faecalis

Serious Enterococcus faecalis infections usually require combination therapy to achieve a bactericidal effect. In orthopedic infections, the prognosis of enterococcal etiology is considered poor, and the use of aminoglycosides is questioned. The ampicillin-ceftriaxone combination has recently been accepted as alternative therapy for enterococcal endocarditis. After one of our patients with endocarditis and vertebral osteomyelitis was cured with ampicillin-ceftriaxone, we started a pilot study of orthopedic infections. Patients with infections due to E. faecalis (with two or more surgical samples or blood cultures) diagnosed during 2005 to 2008 were recruited. Polymicrobial infections with ampicillin- and ceftriaxone-resistant microorganisms were excluded. Patients received ampicillin (8 to 16 g/day)-ceftriaxone (2 to 4 g/day) and were followed up prospectively. Of 31 patients with E. faecalis infections, 10 received ampicillin-ceftriaxone. Including the first patient, 11 patients were treated with ampicillin-ceftriaxone: 3 with prosthetic joint infections, 3 with instrumented spine arthrodesis device infections, 2 with osteosynthesis device infections, 1 with foot osteomyelitis, and 2 with vertebral osteomyelitis and endocarditis. Six infections (55%) were polymicrobial. All cases except the vertebral osteomyelitis ones required surgery, with retention of foreign material in six cases. Ampicillin-ceftriaxone was given for 25 days (interquartile range, 15 to 34 days), followed by amoxicillin (amoxicilline) being given to seven patients (64%). One patient with endocarditis died within 2 weeks (hemorrhagic stroke) and was not evaluable. For one patient with prosthesis retention, the infection persisted; 9/10 patients (90%) were cured, but 1 patient was superinfected. Follow-up was for 21 months (interquartile range, 14 to 36 months). Ampicillin-ceftriaxone may be a reasonable synergistic combination to treat orthopedic infections due to E. faecalis. Our experience, though limited, shows good outcomes and tolerability and may provide a basis for further well-designed comparative studies.

[Oxygen metabolism in isolated rat hepatocytes in obesity. Influence of vitamin C]

Nutritional obesity induced by the ingestion of hyperlipidic diet implies a high consume of lipids, which might be involved in oxygen metabolism. Double bound, in the fatty-acid molecules are a vulnerable point to undergo oxidation reactions-generating lipid peroxidation, that are potentially toxic and can produce serious cell injury (alteration in cell permeability and prostaglandins...). To prevent this oxidative injury the aerobic organisms have intracellular mechanisms of defense, the antioxidant systems, that may be classified as enzymatic and nonenzymatic. Vitamin C belongs to the second group and acts as scavenger of free radicals and other species. The purpose of this study was to evaluate the oxygen metabolism in isolated hepatocytes of rats which obesity has been reached by the ingestion of an hyperenergetic olive-oil rich controlled liquid diet and evaluate the effect of ascorbic acid. Cellular oxidative injury in isolated hepatocytes was induced through a lipid peroxidative and cytotoxic molecule tert-butyl-hydroperoxide (t-BOOH). Results show higher levels of lactate dehydrogenase (LDH) leakage and malondialdehyde (MDA) production in obese rats as compared with controls. Otherwise, when these groups are supplemented with ascorbic acid these changes decrease significantly. ATP levels decrease in hepatocytes of obese rats incubated in the presence of 1 mM tert-butylhydroperoxide. While it is maintained in ascorbic acid supplemented animals. GSH values were lower in hepatocytes from obese and control rats, incubated with tert-butyl-hydroperoxide. Supplementation with ascorbic acid also maintained GSH levels thus indicating that ascorbic acid is acting as an efficient antioxidant.

The biological tests used in acute-phase of inflammation in bone infection : Clinical study

We present a comparative study of different biological tests in the acute phase of inflammation. The study was performed in 80 patients after surgical procedures in septic cases. We have compared the levels of C-Reactive Protein (CRP), C3, C3a, C4, T(o), sedimentation rate, and the leucocyte count. The analysis was made before surgery and every week until the ninth week after surgery. The variations in CRP which ocurred very early were extensive. The increase ranged between 200 and 600% after the surgical procedure. In cases without complications the CRP level returned to normal within 20 days. The study showed the CRP as the most specific and sensitive biological test of the acute phase of inflammation. However this biological test cannot differentiate between an acute infective and a severe inflammatory process.

Protein synthesis is stimulated in nutritionally obese rats

To investigate the tissue growth and the protein synthesis in vivo in nutritional obesity we used lipid-rich multichoice diet feeding. Young male rats of the Wistar strain were divided in two groups: control and obese. Control rats were fed pelleted nonpurified diet. Obese rats were fed a multichoice diet based on a variety of highly palatable energy-rich human foods for 30 d. Protein intake was kept equal in the groups to avoid its influence on protein turnover. The tissue growth pattern was evaluated by protein, DNA and RNA contents of liver, kidney, heart, skeletal muscles and small intestine. Protein synthesis in vivo was measured in these tissues by the phenylalanine flooding-dose technique. Rats fed the multichoice diet showed significantly greater body growth when compared with rats fed the nonpurified diet. Adipose and other tissue weights were significantly greater in the obese rats. The tissue growth pattern was characterized mainly by hyperplasia. In most tissues the net protein accretion found in obese rats resulted from an enhancement in the fractional rate of protein synthesis. The greater protein synthesis was due to an increase in the efficiency of ribosomes in kidney, heart and skeletal muscle and to an increase in the synthetic capacity in liver and small intestine. These data suggest that excess energy intake when protein intake is adequate stimulates tissue growth and protein synthesis in rats.

Protein synthesis in vivo in rats fed on lipid-rich liquid diets

Changes in tissue composition and protein synthesis ratio were studied in the major tissues of the body in young rats fed on lipid-rich, isonitrogenous purified liquid diets, a convenient method for inducing voluntary overfeeding under controlled nutritional conditions. Overfed rats showed faster growth induced by the energy excess. Analysis of tissue composition (protein, DNA and RNA contents) revealed that growth was due mainly to tissue hyperplasia in which protein and DNA contents increased in parallel. Fractional protein synthesis ratio measured in vivo by the flooding-dose method of phenylalanine showed a marked increase in all tissues. This change could be attributed to an increase in the ribosomal activity for protein synthesis in most tissues. Therefore, our results indicate that addition of a supplementary energy source (as lipids) to a well-balanced diet improves growth and protein synthesis in growing rats.

Improved nitrogen metabolism in rats fed on lipid-rich liquid diets

N metabolism was studied in young rats fed on lipid-rich, isonitrogenous, purified liquid diets, a convenient and easy technique for inducing voluntary overfeeding of energy and lipids under controlled nutritional conditions. Overfed rats showed a marked N retention at the expense of a reduced production of urea. The capacities of isolated hepatocytes to synthesize urea and glucose from added precursors were greatly diminished. The activities of the urea cycle enzymes and several enzymes involved in the availability of NH3 for this pathway were concomitantly reduced in overfed animals. Therefore, our results showed an improved N metabolism in overfed rats promoted by the overfeeding of lipids that could be due to an enhanced biosynthetic utilization and a reduced catabolism of amino acids. In addition, the versatile and accurate technique for inducing overfeeding in young rats used in the present study could have many advantages for nutritional studies.

[Acute renal failure after major surgery: effectiveness of continuous arterio-venous hemofiltration (CAVH)]

Thirteen patients with acute renal failure after mayor surgery were treated with CAVH, 6 children after liver transplantation (OLT) and 7 after extracorporeal cardiac surgery (ECS). The ages ranged from 4 months to 19 years, with filters from 0.16 m2 to 0.5 m2, according to the weights. CAVH was initiated 19 hours (mean) after OLT and 10.5 hours (mean) after ECS. Mean creatinine clearance was 6.3 ml/min/1.73 m2 (ECS) and 10.1 ml/min/1.73 m2 (OLT). Serum creatinine remained under acceptable values (mean 2.1 mg.%) in both groups. Mean fluid removal was 5.7 L/day (242 ml/kg/day), which allowed plasma administration despite oligoanuria in the OLT group. Fluid removal decreased central venous pressure (p < 0.001) and increased mean arterial pressure (p < 0.01) in the ECS group, and inotropic support could be diminished. CAVH was well tolerated and it was maintained for 79 hours (ECS) and 105 hours (OLT).

Nitrogen metabolism in obesity induced by monosodium-L-glutamate in rats

We have studied the effects of subcutaneous administration of monosodium-L-glutamate (MSG) to neonatal rats on nitrogen metabolism and on general parameters at several intervals after MSG treatment. As MSG-treated rats were hypophagic, all experiments were performed both in control rats pair-fed with the MSG-treated rats and in control rats fed ad libitum. Lee index, total serum lipids and weight of the epididymal fat depots were higher in MSG-treated rats. Body and tissue weights and the amount of protein in several tissues were lower in adult MSG-obese rats than in control rats. Locomotor activity was decreased following MSG administration. Creatinine clearance was diminished by about 50% in rats treated with MSG. Urinary nitrogen and urea excretion were lower, except at four weeks, and serum urea was higher in MSG-obese rats. Considering liver size, urea synthesis by isolated hepatocytes and urea cycle enzyme activities were increased in weanling MSG obese rats and diminished in adult MSG-obese rats when compared with ad libitum controls but were not changed compared with their pair-fed controls. It is concluded that administration of monosodium-L-glutamate shortly after birth induced an increase in urea synthesis in weanling rats that was followed by a reduction in the amount of tissue proteins, suggesting that more amino acids were used for lipid synthesis and urea production in treated rats. The accelerated amino acid degradation slowed down in adult MSG-obese rats which showed an in vitro capacity to synthesise urea similar to that of their pair-fed controls.

[Transposition of the great arteries. A follow-up of patients operated on with atrial correction]

The late results of 146 patients with transposition of the great arteries (simple: 119, complex: 27) surviving to physiological correction (Mustard: 33, Senning: 113) are analyzed. The mean age at operation was 27 months (1-120), and the mean follow-up was 78 months (6-187). The mean P wave voltage significantly decreased (from 0.3 mV preoperatively to 0.16 mV postoperatively). Frontal mean P wave axis varied from 63.9 degrees to 71.3 degrees. Mean heart rate were significantly lower than those for age-matched normal children. Previous atrioseptectomy had been performed in 36 patients and five of them had arrhythmias before operation. 78 (55%) out of the remaining 141 showed arrhythmias in the surface ECG: sinus node disfunction in 51, tachyarrhythmias in eight, atrioventricular block in eight and several association of arrhythmias in 11. Actuarial survival free of arrhythmias is 81% at the first year, 49% at 5 years and 22% at 15 years. The incidence of arrhythmias in the group of 92 patients with Holter monitoring was higher, with 73 cases having arrhythmias (79%): sinus node disfunction in 47, tachyarrhythmias in ten, atrioventricular block in four and associated in 12. Survival free of arrhythmias by both methods (ECG and Holter) shows a 78% at the first year, 28% at 5 years and 5.6% at 15 years. No significant correlation was found between the incidence of arrhythmias and the type of TGA (simple or complex) or the surgical technique (Mustard or Senning). Permanent pacemakers were implanted in seven to a mean follow-up of 7 years. Five patients were reoperated to a mean follow-up of 46 months. There were 7 late deaths to a mean follow-up of 13 months, four of them being sudden. The actuarial survival rate for the whole group was 93.5% at 15 years. No significant correlation was found between the late mortality and the type of TGA or operation. There was also no correlation with the incidence of arrhythmias. Residual lesions were found in 46 patients, hemodynamically significant in ten. Functional status was class I (NYHA) in 123, and class II in 16. There was correlation between the functional class and the residual lesions.

Electrophysiologic changes during acute rejection of heterotopically transplanted rat hearts

Noninvasive monitoring of heart allograft rejection was performed by electrophysiologic techniques using an implanted electrode located on the epicardial surface of the heterotopic transplanted heart of rats. R wave and slew rate determinations were performed daily in 30 syngeneic and 66 allogeneic transplants. These determinations were later compared with histopathologic studies of the transplanted hearts. R wave and slew rate values of allogeneic or rejecting hearts were found to decrease significantly compared with syngeneic or nonrejecting hearts on the days studied. This noninvasive electrophysiologic method may be a promising method for monitoring heart allograft rejection.

Electrophysiological and anatomical findings in heart transplantation: experimental study

The diagnosis of acute rejection by electrophysiological methods is based on the fact that signs of rejection such as inflammatory infiltrate, interstitial edema, and mostly myocyte necrosis lead to obligated alterations in electrophysiological properties of the myocardium. In a total of 276 heterotopic abdominal transplants in rats, a noninvasive monitoring of heart allograft rejection by conventional ECG and electrophysiological techniques was performed. The correlation of these findings with pathological studies, including histologic determination of the degree of acute rejection, analysis of weight and cardiac perimeter, and volumetric cell density were also evaluated in 96 of them, 66 were allogeneic and 30 syngeneic. Sensitivity and specificity of the R wave and slew rate was also determined with respect to the Billingham classification. Results of the correlation analysis showed that electrophysiological variations in R wave and slew rate correlated more intensely with changes in volumetric cell density. The greatest sensitivity and specificity was observed in R wave changes in relation to the Billingham classification.

[Priapism associated with Fabry's disease]

We present a rare case of priapism in a child, ten years old, in association with Fabry's disease. The child had a history of disseminated nodular enlargement, crises of fever, intermittent pain in the extremities and ten hours persistent painful erection of the penis. We don't obtain pain or erection relief with sedation, epidural block and irrigation of the corporal bodies. A saphenous-cavernous shunt, in the Grayhack fashion made, being results satisfactory. In the follow-up, the child had sporadic pain in the extremities and no erection of the penis. The cavernosography showed the shunt open. Fabry's disease was confirmed by nodular biopsy and the demonstration of deficient alpha-galactosidase.

Effect of probenecid and benzbromarone on gluconeogenesis in isolated rat liver cells

The effect of benzbromarone on gluconeogenesis from several gluconeogenic substrates in isolated rat liver cells is reported. Benzbromarone inhibited glucose synthesis from all substrates employed when the drug was used at concentrations half to ten times greater than its therapeutic plasma levels. This inhibition was more pronounced from lactate and pyruvate than from fructose and glycerol. The results are compared with those obtained for probenecid, a classical uricosuric drug. We found that probenecid inhibited the pathway in the same way as benzbromarone.

[Design, efficiency and application of experimental methods in heart transplantation]

Heart transplantation in children with end-stage heart disease or severe congenital heart defect with uncertain surgical palliation, like the hypoplastic left heart syndrome, has become an accepted form of therapy in certain selected Medical Centers. Increasing number of heart transplantation in children have resulted from increased survival attributable to the introduction of cyclosporine. Nevertheless, the diagnosis of rejection in infants and children remains controversial being a great challenge derived by the need for repetitive and routine heart biopsies. Taking in mind that a non-invasive electrophysiologic method could be considered a promising method for monitoring heart allograft rejection the present study was begun. A total of 306 heart transplantation was performed, 206 heterotopic on rats and 30 orthotopic on dogs. Non-invasive monitoring of heart rejection was made by electrophysiologic techniques using an epicardial lead implanted on the donor heart. R wave and slew-rate measurements were performed daily at 30', primero, segundo, tercero quinto and séptimo day postransplant. These measurements were later compared to histopathologic studies. R wave and slew-rate values of alogenic or rejecting hearts were found to decrease significantly as compared to singenic or non-rejecting heart along the days. This non-invasive electrophysiologic method may be considered a promising and suitable method for monitoring heart allograft rejection.

[Surgery of congenital cardiopathies without catheterization: initial experience with 141 consecutive cases]

Our initial experience with surgical treatment of congenital heart disease in 141 consecutive cases without the need of hemodynamic study is described. Ages ranged between 1 day and 15 years; 39 cases under 1 months of age (23 in the first week of life), 38 between 1 and 12 months, and 64 above 1 year of age. Diagnosis were: ductus 32 cases, atrial septal defect 24, Fallot's tetralogy 14, aortic coarctation 13, complete AV canal defect 7, D-transposition of the great arteries 5, ventricular septal defect 6, pulmonary atresia with intact ventricular septum 5, aortic stenosis 3, tricuspid atresia 4, pseudotruncus 2, univentricular heart 2, atrial myxomas, 2, Fallot's like 3, other type of congenital heart defect 19 cases. There was an adequate correlation between eco-2D images and anatomic-surgical findings. In conclusion, we think that a great percentage of cases affected of congenital heart disease should be considered for surgery without the need of a hemodynamic and angiocardiographic study.

Lipid composition, fluidity and enzymatic activities of rat liver plasma and mitochondrial membranes in dietary obese rats

Total lipids and fatty acid composition were determined in liver plasma and mitochondrial membranes from control and dietary obese rats after 4 weeks of the experimental period. The lipid composition of liver plasma and mitochondrial membranes showed an increase of triacylglycerols in obese rats. The liver plasma membranes showed a decrease of saturated/unsaturated fatty acid ratio and an increase of (n-6) polyunsaturated fatty acids, whereas the (n-3) polyunsaturated acids were decreased. Contrary to what occurs with plasma membranes, few modifications were observed in mitochondrial membranes. Changes of the fatty acid composition of the phospholipid bilayer are of potentially great importance in structural and functional parameters of membrane. Fluidity of liver plasma membranes of dietary obese rats was highly increased, while the mitochondrial ones remained unchanged. These results can be well explained by the decreased saturated/unsaturated fatty acid ratio. A significant decrease of (Na+-K+) ATPase activity (a membrane bound enzyme) was found in plasma membranes of dietary obese rats. Mitochondrial enzymatic activities and oxidative phosphorylation showed few changes except a small, but significant decrease of state 3 respiratory rate. In this study we also determined the fatty acid composition of all the foods offered to animals and their daily intakes in order to discuss their possible influence on changes in structural and functional membrane parameters.

Effect of a hyperlipidic diet on lipid composition, fluidity, and (Na+-K+)ATPase activity of rat erythrocyte membranes

Feeding rats a hyperlipidic diet in which animals were offered daily a variety of high-energy food resulted in a significant increase of serum free fatty acids and a decrease of phospholipids with respect to controls. On the contrary, there were no significant differences in erythrocyte membrane total lipid composition between the two groups. Erythrocyte membranes showed a significant decrease in saturated fatty acid content and a significant increase in (n-6) polyunsaturated fatty acid content; (n-3) polyunsaturated fatty acids significantly decreased. Membrane fluidity, investigated by fluorescence polarization of diphenylhexatriene, significantly increased in the erythrocyte membranes of the experimental group. These results seem compatible with the decreased saturated/unsaturated fatty acid ratio. A significant decrease of (Na+-K+)ATPase activity occurred in erythrocyte membranes of the experimental group rats with respect to the controls.

An enzyme immunoassay for the quantitation of rat liver carbamoyl-phosphate synthetase I

An indirect, competitive enzyme-linked immunosorbent assay for the quantitation of carbamoyl-phosphate synthetase I (ammonia) in rat liver has been developed. Homogenization of the liver in 1% sodium deoxycholate is used for complete solubilization of the enzyme. The detergent does not interfere with the method if diluted to a concentration of 0.01% or lower. The assay is applied to determine the amount of enzyme in control rats and in rats fed "cafeteria" or high-protein diets. Changes in the amount of carbamoyl-phosphate synthetase I (ammonia) paralleled changes in enzymatic activity.

Effect of thyroid hormones on urea biosynthesis and related processes in rat liver

The results of the few studies on the effect of the thyroid status on nitrogen metabolism have been inconclusive and/or contradictory. In an attempt to elucidate this important relationship, we have studied the effect of experimental hypo- and hyperthyroidism on urea biosynthesis and related processes. We have found that the capacity of the liver to synthesize urea was increased in hypothyroid rats, as were the activities of the urea cycle enzymes; there were also changes in the activities of some related enzymes and in the levels of intermediates and amino acids. Isolated hepatocytes from these rats showed an increased capacity for urea synthesis. In hyperthyroid rats the picture was more complicated, since there was no change in the urea-synthesizing capacity of the liver, although there were changes in some enzymes and metabolites. Our results suggest that there may be more endogenous proteolysis in hypothyroidism which would increase ammonia production, the ammonia being used primarily for urea biosynthesis and, to a lesser extent, for glutamate and aspartate synthesis. These overall effects might be the result of an increase in glucagon and/or cAMP, which, as is well known, increase the urea-synthesizing capacity of liver. In hyperthyroidism, on the other hand, the changes in nitrogen metabolism could be the result of an increase in protein synthesis, a decrease in catabolic activity, or both.

Inhibition of purine catabolism by benzbromarone in isolated rat liver cells. Comparison with allopurinol and probenecid

Benzbromarone, a potent uricosuric agent, inhibited allantoin production in isolated hepatocytes at concentrations half to ten times greater than therapeutic plasma levels of the drug. In addition, the drug at these concentrations also markedly inhibited xanthine oxidase (EC 1.2.1.37), an enzyme involved in the regulation of this pathway. We found that allopurinol is several times superior to benzbromarone in the lowering of allantoin production (if they are compared in terms of their relative therapeutic levels), and that probenecid had no effect on it.

Seasonal Variation of Essential Oil Yield and Composition of Thymus hyemalis

The aerial parts of THYMUS HYEMALIS Lange were collected throughout its complete vegetative cycle (April 1981 to March 1982) from the same locality. The yield and composition of essential oil have been determined in eleven samples with special reference to the content of 1,8-cineole, camphor, thymol, and carvacrol. It was found that the yield and composition of the oil changed from month to month. On the basis of the results obtained, July might be proposed as the most suitable month for harvesting T. HYEMALIS, giving the maximum yield in essential oil, which is especially rich in terpenic hydrocarbons at this time. Maximum levels of 1,8-cineole in August, however, might warrent harvesting during this month as well.

Studies on the role of insulin in N metabolism changes in cafeteria-fed rats

The present work studies the serum insulin response to cafeteria feeding and the possible role of this hormone in the marked N retention induced by cafeteria feeding. Rats fed a cafeteria diet for periods of 10, 20 and 30 days showed a significant and progressive increase in serum insulin levels. In order to elucidate the possible intervention of this hormone in the marked N retention induced by cafeteria feeding we studied the changes in N metabolism in non-diabetic and streptozotocin-diabetic rats fed a cafeteria diet for 10 days. The amount of N ingested was the same in all experimental groups. Our results suggest that insulin is not absolutely indispensible in the N retention exhibited by cafeteria-fed rats, inasmuch as cafeteria feeding also promotes a decrease in N excretion in streptozotocin-diabetic rats. This is in accordance with the reduction in urea excretion and the activities (U/g liver) of the ureogenic enzymes in streptozotocin-diabetic rats fed a cafeteria diet.

Inhibition of ureogenesis in isolated rat liver cells by a non-steroidal anti-inflammatory drug (butibufen)

The effect of a non-steroidal anti-inflammatory drug (butibufen) on ureogenesis in isolated rat hepatocytes has been studied. Butibufen at 0.4 mM, and particularly at 2 mM, strongly inhibited urea synthesis. The drug at these concentrations also inhibited markedly carbamoylphosphate synthetase activity. In addition, 2 mM butibufen lowered ATP concentrations of the cells and enhanced oxygen consumption in isolated liver mitochondria. The results suggest that the inhibition by 0.4 mM butibufen on carbamoylphosphate synthetase activity can account for the entire inhibition of ureogenesis, whereas the decreased cellular ATP concentration at 2 mM butibufen might be at least partly responsible for low carbamoylphosphate synthesis and thus, for reduced urea production. The decrease in ATP levels probably results from uncoupling effects of butibufen on oxidative phosphorylation.

Decreased urea synthesis in cafeteria-diet-induced obesity in the rat

Feeding rats with a cafeteria diet resulted in increases in total body weight and in epididymal-adipose-tissue weight. Those rats excreted significantly less N than did controls. The amount of N ingested by cafeteria-diet-fed rats was kept equal to that of controls. This decrease in N excretion is explained by a decrease in urinary excretion of urea. This may be due to the following facts. The rate of synthesis of urea from precursors by isolated hepatocytes from cafeteria-diet-fed rats was lower than in controls. In cafeteria-diet-fed rats the activities of all the enzymes of the urea cycle are decreased. The major percentage decreases are those of carbamoylphosphate synthetase (EC 6.3.4.16) and of argininosuccinate synthetase (EC 6.3.4.5), the enzymes probably involved in the regulation of the overall rate of the cycle. When rats are switched to normal chow diet, the enzyme activities return to normal values. The uptake of amino acids by liver of cafeteria-diet-fed rats is lower than in controls. These results contrast with those obtained previously by using other models of obesity in rat (i.e. genetic or hypothalamic), in which N excretion was increased.