Low rCBV values in glioblastoma tumor progression under chemoradiotherapy

PURPOSE

After standard treatment for glioblastoma, perfusion MRI remains challenging for differentiating tumor progression from post-treatment changes. Our objectives were (1) to correlate rCBV values at diagnosis and at first tumor progression and (2) to analyze the relationship of rCBV values at tumor recurrence with enhancing volume, localization of tumor progression, and time elapsed since the end of radiotherapy in tumor recurrence.

METHODS

Inclusion criteria were (1) age > 18 years, (2) histologically confirmed glioblastoma treated with STUPP regimen, and (3) tumor progression according to RANO criteria > 12 weeks after radiotherapy. Co-registration of segmented enhancing tumor VOIs with dynamic susceptibility contrast perfusion MRI was performed using Olea Sphere software. For tumor recurrence, we correlated rCBV values with enhancing tumor volume, with recurrence localization, and with time elapsed from the end of radiotherapy to progression. Analyses were performed with SPSS software.

RESULTS

Sixty-four patients with glioblastoma were included in the study. Changes in rCBV values between diagnosis and first tumor progression were significant (p < 0.001), with a mean and median decreases of 32% and 46%, respectively. Mean rCBV values were also different (p < 0.01) when tumors progressed distally (radiation field rCBV values of 1.679 versus 3.409 distally). However, changes and, therefore, low rCBV values after radiotherapy in tumor recurrence were independent of time.

CONCLUSION

Chemoradiation alters tumor perfusion and rCBV values may be decreased in the setting of tumor progression. Changes in rCBV values with respect to diagnosis, with low rCBV in tumor progression, are independent of time but related to the site of recurrence.

Sinus bradycardia as the initial manifestation of multisystem inflammatory syndrome in children

Background

While cardiovascular complications, including arrhythmias are now a recognized manifestation of Multisystem inflammatory syndrome in children (MIS-C), there are no reports of primary bradycardia preceding the clinical presentation. We sought to describe a case series of sinus bradycardia as an initial manifestation of MIS-C.

Methods

We included a series of 10 consecutive patients with confirmed COVID-19 who met WHO and CDC criteria for MIS-C, who developed sinus bradycardia with a heart rate measured in the awake state that was below the normal range for age for children, as an initial manifestation of the disease, in a prospective observational multicenter study. Patients underwent clinical, laboratory evaluation, ECG, Holter, telemetry, echocardiogram, chest X Ray, and a chest CT scan.

Results

Of the 10 patients included, 6 were male, with a mean age of 6.52±5.35 years, range 4 months to 14 years. All cases were Hispanic. Bradycardia was transient and did not merit treatment. Coronary abnormalities were noted in 6 cases; 4 patients had mild coronary ectasia; 9 patients had pericardial effusion with no evidence of tamponade. All patients had a mild clinical course; none had shock, heart failure, the need for mechanical ventilation, or died. All blood markers (Troponin, BNP, Platelet count, C-reactive protein, D-dimer, Ferritin) returned to normal levels by discharge/follow-up with a favorable outcome including resolution of coronary dilatation in all but 2 in which aneurysm persisted.

Treatment

All patients received steroids and low-weight-molecular heparin 10 patients, 8 aspirin and 8 intravenous immunoglobulins.

Conclusion

Sinus bradycardia may be the initial manifestation of MIS-C, usually transient and mild. Physicians should be aware of this presentation.

Funding Acknowledgement

Type of funding sources: None.

Erratum: Azimuthal Anisotropy of K_{S}^{0} and Λ+Λ[over ¯] Production at Midrapidity from Au+Au Collisions at sqrt[s]_{NN}=130 GeV [Phys. Rev. Lett. 89, 132301 (2002)]

This corrects the article DOI: 10.1103/PhysRevLett.89.132301.

Pancreatic cancer prognosis is predicted by an ATAC-array technology for assessing chromatin accessibility

Unlike other malignancies, therapeutic options in pancreatic ductal adenocarcinoma (PDAC) are largely limited to cytotoxic chemotherapy without the benefit of molecular markers predicting response. Here we report tumor-cell-intrinsic chromatin accessibility patterns of treatment-naïve surgically resected PDAC tumors that were subsequently treated with (Gem)/Abraxane adjuvant chemotherapy. By ATAC-seq analyses of EpCAM+ PDAC malignant epithelial cells sorted from 54 freshly resected human tumors, we show here the discovery of a signature of 1092 chromatin loci displaying differential accessibility between patients with disease free survival (DFS) < 1 year and patients with DFS > 1 year. Analyzing transcription factor (TF) binding motifs within these loci, we identify two TFs (ZKSCAN1 and HNF1b) displaying differential nuclear localization between patients with short vs. long DFS. We further develop a chromatin accessibility microarray methodology termed "ATAC-array", an easy-to-use platform obviating the time and cost of next generation sequencing. Applying this methodology to the original ATAC-seq libraries as well as independent libraries generated from patient-derived organoids, we validate ATAC-array technology in both the original ATAC-seq cohort as well as in an independent validation cohort. We conclude that PDAC prognosis can be predicted by ATAC-array, which represents a low-cost, clinically feasible technology for assessing chromatin accessibility profiles.

Heterogeneous ozone effects on the DNA methylome of bronchial cells observed in a crossover study

We used a randomized crossover experiment to estimate the effects of ozone (vs. clean air) exposure on genome-wide DNA methylation of target bronchial epithelial cells, using 17 volunteers, each randomly exposed on two separated occasions to clean air or 0.3-ppm ozone for two hours. Twenty-four hours after exposure, participants underwent bronchoscopy to collect epithelial cells whose DNA methylation was measured using the Illumina 450 K platform. We performed global and regional tests examining the ozone versus clean air effect on the DNA methylome and calculated Fisher-exact p-values for a series of univariate tests. We found little evidence of an overall effect of ozone on the DNA methylome but some suggestive changes in PLSCR1, HCAR1, and LINC00336 DNA methylation after ozone exposure relative to clean air. We observed some participant-to-participant heterogeneity in ozone responses.

The Salivary Mycobiome Contains 2 Ecologically Distinct Mycotypes

A broad range of fungi has been detected in molecular surveys of the oral mycobiome. However, knowledge is still lacking on interindividual variability of these communities and the ecologic and clinical significance of oral fungal commensals. In this cross-sectional study, we use internal transcribed spacer 1 amplicon sequencing to evaluate the salivary mycobiome in 59 subjects, 36 of whom were scheduled to receive cancer chemotherapy. Analysis of the broad population structure of fungal communities in the whole cohort identified 2 well-demarcated genus-level community types (mycotypes), with Candida and Malassezia as the main taxa driving cluster partitioning. The Candida mycotype had lower diversity than the Malassezia mycotype and was positively correlated with cancer and steroid use in these subjects, smoking, caries, utilizing a removable prosthesis, and plaque index. Mycotypes were also associated with metabolically distinct bacteria indicative of divergent oral environments, with aciduric species enriched in the Candida mycotype and inflammophilic bacteria increased in the Malassezia mycotype. Similar to their fungal counterparts, coexisting bacterial communities associated with the Candida mycotype showed lower diversity than those associated with the Malassezia mycotype, suggesting that common environmental pressures affected bacteria and fungi. Mycotypes were also seen in an independent cohort of 24 subjects, in which cultivation revealed Malassezia as viable oral mycobiome members, although the low-abundance Malassezia sympodialis was the only Malassezia species recovered. There was a high degree of concordance between the molecular detection and cultivability of Candida, while cultivation showed low sensitivity for detection of the Malassezia mycotype. Overall, our work provides insights into the oral mycobiome landscape, revealing 2 community classes with apparently distinct ecologic constraints and specific associations with coexisting bacteria and clinical parameters. The utility of mycotypes as biomarkers for oral diseases warrants further study.

Review article: the diagnostic approach and current management of chylous ascites

BACKGROUND

Chylous ascites is rare, accounting for less than 1% of cases. An appropriate and stepwise approach to its diagnosis and management is of key importance.

AIM

To review the current diagnostic approach and management of chylous ascites.

METHODS

A literature search was conducted using PubMed using the key words 'chylous', 'ascites', 'cirrhosis', 'pathophysiology', 'nutritional therapy', 'paracentesis", "transjugular intrahepatic portosystemic shunt" and "TIPSS'. Only articles in English were included.

RESULTS

Chylous ascites is caused by the traumatic or obstructive disruption of the lymphatic system that leads to extravasation of thoracic or intestinal lymph into the abdominal space and the accumulation of a milky fluid rich in triglycerides. The most common causes are malignancy, cirrhosis and trauma after abdominal surgery. This condition can lead to chyle depletion, which results in nutritional, immunologic and metabolic deficiencies. An ascitic triglyceride concentration above 200 mg/dL is consistent with chylous ascites. Treatment is based on management of the underlying cause and nutritional support.

CONCLUSIONS

Chylous ascites is mostly due to malignancy and cirrhosis in adults, and congenital lymphatic disorders in children. Treatment with nutritional optimization and management of the underlying etiology are the cornerstones of therapy. When conservative measures fail, other interventions such as octreotide/somatostatin analogues, surgical ligation, embolization and transjugular intrahepatic portosystemic shunt in patients with cirrhosis can be considered.

Review article: the management of portal hypertensive gastropathy and gastric antral vascular ectasia in cirrhosis

BACKGROUND

Portal hypertensive gastropathy (PHG) and gastric antral vascular ectasia (GAVE) are important causes of both acute and chronic gastrointestinal bleeding in patients with cirrhosis.

AIM

To review the current management of PHG and GAVE.

METHODS

PubMed was searched for English language articles using the key words 'GAVE', 'gastric antral vascular ectasia', 'cirrhosis', 'gastrointestinal bleeding', 'acute', 'chronic', 'portal hypertensive gastropathy', 'watermelon stomach', 'radiofrequency ablation', 'band ligation', 'thermoablation' and 'TIPSS'.

RESULTS

GAVE and PHG are both encountered in patients with cirrhosis. They can be seen in asymptomatic patients and in those with either acute or chronic gastrointestinal bleeding. PHG, by definition, requires the presence of portal hypertension, with or without cirrhosis, whereas GAVE requires neither cirrhosis nor portal hypertension. They can often be diagnosed on endoscopic appearance alone, but may require biopsy in certain cases. The treatment of PHG is aimed at reducing hepatic venous pressure gradients, most often by pharmacologic means, but may require shunt procedures in severe cases. Management of GAVE on the other hand is predominantly endoscopic, focusing on various ablative techniques.

CONCLUSIONS

Gastric antral vascular ectasia and portal hypertensive gastropathy are distinct entities and are both encountered in cirrhotic patients. Management of portal hypertensive gastropathy is centred on reduction in portal pressures, whereas treatment of gastric antral vascular ectasia is predominantly endoscopic.

Acquired urethral obstruction in New World camelids: 34 cases (1995-2008)

OBJECTIVE

Document the clinical features, short- and long-term outcomes and prognostic factors in New World camelids with acquired urethral obstruction.

DESIGN

Retrospective case study.

METHODS

Case data from medical records of 34 New World camelids presenting with acquired urethral obstruction were collected and follow-up information on discharged patients was obtained. Associations with short- and long-term survival were evaluated using Wilcoxon rank-sum tests, exact-logistic regressions and Kaplan-Meier survival curves.

RESULTS

Of the 34 New World camelids 23 were intact males and 11 were castrated; 4 animals were euthanased upon presentation, 7 were treated medically and 23 surgically, including urethrotomy, bladder marsupialisation, tube cystostomy alone or combined with urethrotomy, urethrostomy or penile reefing. Necrosis of the distal penis was found in 4 animals and all were short-term non-survivors. Short-term survival for surgical cases was 65%, and 57% for medical cases. Incomplete urethral obstruction at admission and surgical treatment were associated with increased odds of short-term survival. Of 14 records available for long-term follow-up, 6 animals were alive and 8 were dead (median follow-up 4.5 years, median survival time 2.5 years). Recurrence of urethral obstruction was associated with long-term non-survival.

CONCLUSIONS

Surgically treated New World camelids with incomplete urethral obstruction have the best odds of short-term survival and those with recurrence of urethral obstruction have a poor prognosis for long-term survival.

The optimal cut-off for predicting large oesophageal varices using transient elastography is disease specific

The diagnosis of cirrhosis requires screening for oesophageal varices by upper gastrointestinal endoscopy. In many countries, serological tests and elastography are replacing liver biopsy for diagnosing cirrhosis. The aims of this study were to see whether there was an optimal cut-off of liver stiffness that could predict the presence of large (>F2) oesophageal varices and whether this was disease specific. A total of two hundred and twenty-two patients with all cause cirrhosis (Child class A) were screened, and 211 had successful elastography and are included in the analysis. Of the patients studied, one hundred and thirty-two patients had no or small F1 varices and 79 had large varices. Liver stiffness of 19.8 kPa had a negative predictive value of 91% and a positive predictive value of 55% with an area under the curve (AUC) on receiver operating characteristics (ROC) of 0.73 in differentiating between small and large varices. Seven patients with large varices would have been incorrectly classified. In the 157 patients with hepatitis C as the aetiology of cirrhosis, the negative predictive value was 98% and only one patient was misclassified. Liver stiffness was superior in diagnostic accuracy to platelet count in all patients. A liver stiffness of >19.8 kPa could be utilized as a cut-off for endoscopy and beta blocker utilization, particularly in patients with hepatitis C.

Disposition and metabolism of almotriptan in rats, dogs and monkeys

Almotriptan is a new highly potent selective 5-HT1B/1D receptor agonist developed for the treatment of migraine, and the disposition of almotriptan in different animal species is now addressed in the current study. Almotriptan was well absorbed in rats (69.1%) and dogs (100%) following oral treatment. The absolute bioavailability was variable reflecting different degrees of absorption and first-pass metabolism (18.7-79.6%). The elimination half-life was short and ranged between 0.7 and 3 h. The main route of elimination of almotriptan was urine with 75.6% and 80.4% of the dose recovered over a 168-h period in rats and dogs, respectively. The gamma-aminobutyric acid metabolite formed by oxidation of the pyrrolidine ring was the main metabolite found in urine, faeces, bile, and plasma of rats and in monkey urine. By contrast, the unchanged drug, the indole acetic acid metabolite formed by oxidative deamination of the dimethylaminoethyl group, and the N-oxide metabolite were the main metabolites in dog.

Review article: hepatic hydrothorax

Patients with cirrhosis and portal hypertension often have abnormal extracellular fluid volume regulation, resulting in accumulation of fluid as ascites, oedema or pleural effusion. These complications carry a poor prognosis with nearly half of the patients with ascites dying in the ensuing 2-3 years. In contrast to what happens in the abdominal cavity where large amounts of fluid (5-8 L) accumulate with the patient only experiencing only mild symptoms, in the thoracic cavity smaller amounts of fluid (1-2 L) cause severe symptoms such as shortness of breath, cough and hypoxaemia. Hepatic hydrothorax is defined as a pleural effusion, usually >500 mL, in patients with cirrhosis without cardiopulmonary disease. The pathophysiology involves the direct movement of ascitic fluid from the peritoneal cavity into the pleural space through diaphragmatic defects. The estimated prevalence among cirrhotic patients is 5-10%. The effusion, which is a transudate, most commonly occurs in the right hemithorax. The mainstay of therapy is similar to that of portal hypertensive ascites and includes sodium restriction and administration of diuretics. Refractory hydrothorax can be managed with transjugular intrahepatic portosystemic shunt in selected cases. Pleurodesis is not routinely recommended. Suitable patients with hepatic hydrothorax should be considered candidates for liver transplantation.

Three-pion Hanbury Brown-Twiss correlations in relativistic heavy-ion collisions from the STAR experiment

Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at sqrt[s(NN)]=130 GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freeze-out. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.

Narrowing of the balance function with centrality in Au+Au collisions at the square root of SNN = 130 GeV

The balance function is a new observable based on the principle that charge is locally conserved when particles are pair produced. Balance functions have been measured for charged particle pairs and identified charged pion pairs in Au+Au collisions at the square root of SNN = 130 GeV at the Relativistic Heavy Ion Collider using STAR. Balance functions for peripheral collisions have widths consistent with model predictions based on a superposition of nucleon-nucleon scattering. Widths in central collisions are smaller, consistent with trends predicted by models incorporating late hadronization.

Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

Azimuthal anisotropy and correlations in the hard scattering regime at RHIC

Azimuthal anisotropy (v(2)) and two-particle angular correlations of high p(T) charged hadrons have been measured in Au+Au collisions at sqrt[s(NN)]=130 GeV for transverse momenta up to 6 GeV/c, where hard processes are expected to contribute significantly. The two-particle angular correlations exhibit elliptic flow and a structure suggestive of fragmentation of high p(T) partons. The monotonic rise of v(2)(p(T)) for p(T)<2 GeV/c is consistent with collective hydrodynamical flow calculations. At p(T)>3 GeV/c, a saturation of v(2) is observed which persists up to p(T)=6 GeV/c.

Coherent rho(0) production in ultraperipheral heavy-ion collisions

The STAR Collaboration reports the first observation of exclusive rho(0) photoproduction, AuAu-->AuAurho(0), and rho(0) production accompanied by mutual nuclear Coulomb excitation, AuAu-->Au*Au*rho(0), in ultraperipheral heavy-ion collisions. The rho(0) have low transverse momenta, consistent with coherent coupling to both nuclei. The cross sections at sqrt[s(NN)]=130 GeV agree with theoretical predictions treating rho(0) production and Coulomb excitation as independent processes.

Centrality dependence of high-p(T) hadron suppression in Au+Au collisions at sqrt[s(NN)]=130 GeV

Inclusive transverse momentum distributions of charged hadrons within 0.2<p(T)<6.0 GeV/c have been measured over a broad range of centrality for Au+Au collisions at sqrt[s(NN)]=130 GeV. Hadron yields are suppressed at high p(T) in central collisions relative to peripheral collisions and to a nucleon-nucleon reference scaled for collision geometry. Peripheral collisions are not suppressed relative to the nucleon-nucleon reference. The suppression varies continuously at intermediate centralities. The results indicate significant nuclear medium effects on high-p(T) hadron production in heavy-ion collisions at high energy.

Azimuthal anisotropy of K(0)(S) and Lambda+Lambda production at midrapidity from Au+Au collisions at sqrt[s(NN)]=130 GeV

We report STAR results on the azimuthal anisotropy parameter v(2) for strange particles K(0)(S), Lambda, and Lambda at midrapidity in Au+Au collisions at sqrt[s(NN)]=130 GeV at the Relativistic Heavy Ion Collider. The value of v(2) as a function of transverse momentum, p(t), of the produced particle and collision centrality is presented for both particles up to p(t) approximately 3.0 GeV/c. A strong p(t) dependence in v(2) is observed up to 2.0 GeV/c. The v(2) measurement is compared with hydrodynamic model calculations. The physics implications of the p(t) integrated v(2) magnitude as a function of particle mass are also discussed.

Midrapidity Lambda and Lambda(macro) production in Au+Au collisions at the square root of [s(NN)]=130 GeV

We report the first measurement of strange (Lambda) and antistrange (Lambda macro) baryon production from square root of [s(NN)]=130 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at midrapidity are presented as a function of centrality. The yield of Lambda and Lambda; hyperons is found to be approximately proportional to the number of negative hadrons. The production of Lambda; hyperons relative to negative hadrons increases very rapidly with transverse momentum. The magnitude of the increase cannot be described by existing hadronic string fragmentation models alone.

Measurement of inclusive antiprotons from Au+Au collisions at square root of s(NN) = 130 GeV

We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at square root of s(NN) = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25<p( perpendicular)<0.95 GeV/c are found to fall less steeply for more central collisions. The extrapolated antiproton rapidity density is found to scale approximately with the negative hadron multiplicity density.

d Macro and (3)He macro production in square root of s(NN) = 130 GeV Au+Au collisions

The first measurements of light antinucleus production in Au+Au collisions at the Relativistic Heavy-Ion Collider are reported. The observed production rates for d macro and (3)He macro are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at CERN SPS energy. These analyses also indicate that the (3)He macro freeze-out volume is smaller than the d macro freeze-out volume.

Multiplicity distribution and spectra of negatively charged hadrons in Au+Au collisions at square root of (sNN) = 130 GeV

The minimum-bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons ( h(-)) in Au+Au interactions at square root of ([s(NN)]) = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dN(h(-))/d(eta)/(eta = 0) = 280+/-1(stat)+/-20(syst), an increase per participant of 38% relative to pp collisions at the same energy. The mean transverse momentum is 0.508+/-0.012 GeV/c and is larger than in central Pb+Pb collisions at lower energies. The scaling of the h(-) yield per participant is a strong function of p( perpendicular). The pseudorapidity distribution is almost constant within /eta/<1.

Pion Interferometry of square root of (s(NN)) =130 GeV Au + Au collisions at RHIC

Two-pion correlation functions in Au+Au collisions at square root of [s(NN)] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in square root of [s(NN)].

Midrapidity antiproton-to-proton ratio from Au+Au collisions at sqrt [s(NN)]=130 GeV

We report results on the ratio of midrapidity antiproton-to-proton yields in Au+Au collisions at sqrt[s(NN)] = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of /y/<0.5 and 0.4<p(t)<1.0 GeV/c, the ratio is essentially independent of either transverse momentum or rapidity, with an average of 0.65+/-0.01((stat))+/-0.07((syst)) for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the p-p pair production becomes important at midrapidity, a significant excess of baryons over antibaryons is still present.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Potential for radioactive patient excreta in hospital trash and medical waste

Radioactive excreta from nuclear medicine patients can enter solid waste as common trash and medical biohazardous waste. Many landfills and transfer stations now survey these waste streams with scintillation detectors which may result in rejection of a hospital's waste. Our survey indicated that on the average either or both of Boston University Medical Center Hospital's waste streams can contain detectable radioactive excreta on a weekly basis. To avoid potential problems, radiation detectors were installed in areas where housekeepers carting trash and medical waste must pass through to ensure no radioactivity leaves the institution.

Monitoring of early nephrotoxic effects of industrial chemicals

Long-term exposure to certain industrial chemicals (e.g. heavy metals, some halogenated hydrocarbons) may cause progressive degenerative changes in the kidney, possibly leading to renal insufficiency. The screening tests most widely used to assess the integrity of the kidney (i.e. serum creatinine or BUN and the quantitative or semi-quantitative measurement of total proteinuria) lack sensitivity; they do not permit the detection of renal disturbances at a stage when removal from exposure may prevent progression of the disease process and are not suitable to determine the no-effect levels of potentially nephrotoxic chemicals. During the last decades new markers have been proposed for the early detection of structural and/or functional changes at various sites of the renal parenchyma. Some tests mainly attempt to assess the integrity of the glomerulus (e.g. high Mr proteinuria such as transferrinuria and albuminuria; increased excretion of some components of the glomerular basement membrane or the mesangium matrix, increased plasma concentration of low Mr proteins such as beta 2-microglobulin and free retinol binding protein), the proximal tubule (e.g. urinary excretion of several low Mr plasma proteins, tubular enzymes and antigens), the loop of Henle and distal tubule (e.g. excretion of various prostanoids). Currently, the majority of these tests are of limited value at the individual level because their health significance, even when they are persistently abnormal, has not yet been sufficiently studied. In workers exposed to Cd, however, it has been shown that a persistent low Mr proteinuria is predictive of an exacerbation of the age-related decline of the GFR; this biological change should be considered as an adverse effect. Currently, the principal application of these tests lies in the framework of epidemiologic studies designed to assess permissible exposure levels to nephrotoxic pollutants. The study of dose-effects/response relationships based on a large battery of renal markers has allowed the better determination of the internal dose of Cd, which is not associated with significant renal risk.

Potentiation of diabetic glomerulopathy in uninephrectomized rats subchronically exposed to cadmium

The renal effects of diabetes mellitus and cadmium (Cd), separately or in combination, were investigated in unilaterally nephrectomized female Sprague-Dawley rats. Diabetes was induced by injection of streptozotocin and Cd was administered in drinking water at a concentration of 100 p.p.m. for 2.5 months. Cd did not affect the reduction in glomerular filtration rate or the rise in beta 2-microglobulinuria caused by diabetes. By contrast, the effect of diabetes on the urinary excretion of albumin, transferrin or IgG was greatly enhanced by concomitant exposure to Cd. This interaction occurred at Cd levels in the renal cortex which are very similar to those found in the general population of industrialized countries. These observations, in agreement with the results of a recent epidemiological study, suggest that Cd polluting the environment might potentiate the development of diabetic nephropathy.

Disturbance of sialic acid metabolism by chronic cadmium exposure and its relation to proteinuria

In workers exposed to Cd (8 years on the average), we have found a significant decrease of sialic acid in erythrocyte membranes (22.61 +/- 1.84 vs 25.80 +/- 3.01 micrograms/mg of protein in controls, p less than 0.05) and an increase of sialic acid concentration in both urine (276.7 +/- 132.3 vs 174.5 +/- 70.9 micrograms/g of creatinine, p less than 0.05) and plasma (761.8 +/- 83.5 vs 640.4 +/- 70.7 micrograms/ml, p less than 0.01). In rats exposed to Cd (100 ppm in drinking water for 5.5 months), we have observed a reduction of the sialic acid level in erythrocyte membranes (31.4 +/- 1.2 vs 33.4 +/- 1.1 micrograms/mg of protein, p less than 0.01) and glomeruli (12.5 +/- 1.3 vs 13.9 +/- 1.6 micrograms/mg of protein, p less than 0.05). These effects in Cd treated rats were accompanied by a loss of the glomerular barrier selectively as reflected by an increased urinary output of albumin and transferrin. After 10 months of Cd exposure, the albuminuria and transferrinuria were negatively correlated with the sialic acid content of glomerular membranes (r = -0.47 and -0.51, p less than 0.05), which suggests that the depletion of sialic acid is involved in the loss of glomerular barrier function induced by long term Cd exposure. In Cd-treated rats, sialidase activity was enhanced in kidney cortex and in serum but not in glomeruli.

Effects of pneumotoxic trialkylphosphorothioates on the pentose phosphate pathway in rat lung slices

The extent of glucose oxidation via the pentose phosphate pathway (PPP), a possible indicator of oxidative stress, was assessed in rat lung slices by measuring the production of 14CO2 on incubation with either [6-14C]glucose or [1-14C]glucose. Incubation in the presence of the pneumotoxins O,S,S-trimethyl phosphorodithioate (OSSMe, 10(-5) -10(-3) M), O,O,S-triethyl phosphorothioate (10(-4) -10(-2) M) or S,S,S-trimethyl phosphorotrithioate (10(-4) -10(-2) M) resulted in a significant, but small stimulation of PPP (max. 276%), compared to that found in the presence of the model oxidant, paraquat (1089%, 10(-5) M). Following in vivo treatment with an LD50 dose of OSSMe, PPP was unchanged (after 6 h) or decreased (after 24 h) compared to saline-treated rats. PPP was also decreased in slices which had been preincubated with OSSMe (10(-3) M) and then transferred to fresh medium. Following treatment with phorone (250 mg/kg i.p.) pulmonary levels of non-protein sulfhydryls were first reduced (20% of control at 3 h) and then increased (288% of control at 24 h), but at neither time was lung slice PPP activity affected, thus suggesting that in the rat lung PPP activity does not directly depend on pulmonary glutathione content.

Assessment of urinary protein 1 and transferrin as early markers of cadmium nephrotoxicity

Transferrin and protein 1, a sex linked alpha 2-microprotein, were assayed in urine from 58 workers exposed to cadmium (Cd) in a non-ferrous smelter and from 58 age matched referents. These two new markers of nephrotoxicity were compared with urinary beta 2-microglobulin (beta 2-m), retinol binding protein (RBP), albumin, and beta-N-acetyl-glucosaminidase (NAG). The response of protein 1 to Cd tubulotoxicity was similar to that of beta 2-m, RBP, and NAG. In Cd workers, protein 1 had a correlation with urinary Cd (r = 0.56) similar to beta 2-m (r = 0.48), RBP (r = 0.58), and NAG (r = 0.49). Values of these three low molecular weight proteins and of NAG were increased only in workers with urinary Cd higher than 10 micrograms/g creatinine. Urinary transferrin and albumin were similarly affected by exposure to Cd. Their response, however, was clearly more sensitive than that of low molecular weight proteins. Prevalences of positive values of these two high molecular weight proteins were not only higher but also tended to rise at lower concentrations of Cd in urine or blood. This finding suggests that in some subjects subtle defects in glomerular barrier function may precede the onset of proximal tubular impairment after chronic exposure to Cd. It remains to be assessed whether these subjects are more at risk of developing renal insufficiency.

Inorganic arsenic methylation by rat tissue slices

Rat liver, kidney and lung slices methylate trivalent inorganic arsenic (AsIII) to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA); the liver has the greatest methylating capacity. AsIII enters the liver cells by a diffusion process followed by extensive binding to intracellular components which favors its extensive accumulation inside the cells. Reduced glutathione regulates AsIII metabolism through several mechanisms: facilitation of AsIII diffusion into the cells, stimulation of the first methylation reaction and increase of DMA excretion by the cells. An excess of AsIII inhibits DMA production by liver cells but this inhibition is reversible; mercuric ions inhibit both MMA and DMA production probably by decreasing inorganic arsenic (Asi) uptake and the second methylation reaction. DMA can be produced from MMA by rat liver slices and this methylation step is stimulated by GSH. In contrast to AsIII, AsV is not extensively taken up by the hepatocyte and is thus poorly methylated.

Hilus cell tumor of the ovary and endometrial carcinoma

A case of hilus cell tumour of the ovary was found in a patient with adenocarcinoma of the endometrium, the sixth such case reported in the literature. Serum levels of estradiol-17beta, progesterone, and testosterone were measured before and after surgical removal of the tumor and after dexamethasone suppression in the postoperative period. Only testosterone appeared to be related to the presence of the hilus cell tumor; its levels decreased after removal of the tumor.