Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study

In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24 years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls. The mean ages of cases and controls were 16.5 and 16.6 years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10 years) users: 22% overall, 51% in the 20-24-year-olds. Most tumours were of the neuroepithelial type (NBT; n = 671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15-19 years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour. Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure. Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk.

[Use of wireless telecommunications technologies among the 10-25-year-old in France: Data extracted from the French part of the MOBI-KIDS study]

BACKGROUND

In less than two decades, the wireless telecommunications sector has grown dramatically. While a large part of the world's population is now equipped with technologies from this sector (mobile phone, wireless residential telephone, Wi-Fi…), little data is available to quantify the use of these technologies. The purpose of this article is to present a description of these uses among young people, a population particularly receptive to these new telecommunication facilities.

METHODS

As part of the MOBI-KIDS study, a prospective epidemiological case-control study, 288 participants aged 10 to 25 years and living in France were interviewed between March 2011 and March 2015 about their history of use of wireless telecommunication devices.

RESULTS

At the interview date, 84% of participants regularly used a mobile phone to make voice calls with an estimated cumulative duration of 45minutes per week. Of these users, 97% used the Short Message Service (SMS) sending function and 70% the data exchange functions. Regarding the use of other technologies, 88% of participants used Wi-Fi, for ten hours a week and 56% the wireless residential telephone. These uses, however, varied according to the sex and/or age of the subjects.

CONCLUSION

The data draw a portrait of use, particularly quantitative, of the main wireless communication technologies in this young population. There is a gradual increase with age in the use of these technologies, while the age of initiation is at an increasingly early age.

Are dietary reports in a case-control study on thyroid cancer biased by risk perception of Chernobyl fallout?

BACKGROUND

In retrospective case-control studies performed following nuclear tests or nuclear accidents, individual thyroid radiation dose reconstructions are based on fallout and meteorological data from the residential area, demographic characteristics, and lifestyle as well as dietary information. Collecting the latter is a controversial step, as dietary declarations may be affected by the subjects' beliefs about their risk behavior. This report analyses the potential for such bias in a case-control study performed in eastern France.

METHODS

The study included 765 cases of differentiated thyroid carcinoma matched with 831 controls. Risk perceptions and beliefs of cases and controls were compared using Chi² tests and differences in dietary reports were analyzed using a two-way ANOVA.

RESULTS

In general, atmospheric pollution and living near a nuclear power plant were the two major risks that may influence thyroid cancer occurrence cited by cases and controls. When focusing in particular on the consequences of the Chernobyl accident, cases were more likely to think that the consequences were responsible for thyroid cancer occurrence than controls. Vegetable consumption during the two months after the Chernobyl accident was correlated with the status of subjects, but not to their beliefs. Conversely, consumption of fresh dairy products was not correlated with the status or beliefs of subjects.

CONCLUSION

We found no evidence of systematic bias in dietary reports according to the status or beliefs held by subjects about the link between thyroid cancer occurrence and Chernobyl fallout. As such, these dietary reports may be used in further studies involving individual dosimetric reconstructions.

Calcium uptake into enterocyte brush-border membrane vesicles is greater in spontaneously hypertensive than in normotensive control rats

Arterial hypertension in the SHR is associated with disturbances of calcium homeostasis, compared with its normotensive control, the WKY. In order to study intestinal Ca2+ handling at the subcellular level, we examined 45Ca2+ uptake kinetics in isolated brush-border membrane vesicles (BBMV). Experiments were conducted in male, 12- to 14-week-old rats on a 1% Ca diet. BBMV were purified by the method of Forstner et al. No difference in BBMV enrichment was observed between SHR and WKY. Ca2+ uptake was studied at various Ca2+ concentrations in the incubation medium (0.025-1.0 mM) and could be separated into a nonsaturable and a saturable component. The saturable component followed Michaelis-Menten kinetics. Vmax in the SHR was greater than in the WKY: 0.576 +/- 0.186 (n = 6) vs. 0.346 +/- 0.10 nmol/mg protein x 10 s (n = 6), mean +/- SD, p less than 0.05. However, Km was not different in the two animal strains. In conclusion, mediated Ca2+ transport into duodenal BBMV was increased in the adolescent SHR. When considering that the transcellular duodenal Ca2+ flux is decreased in the SHR at this age, the rate-limiting step of perturbed transeptithelial Ca2+ transport is probably localized at the site of the basolateral membrane.

Nasal polyposis and cystic fibrosis(CF): review of the literature

The aim of this study was to address whether NP might be a predictive factor for severity of CF. The authors collected data from the literature on NP as a unique or associated sign in CF and reviewed the clinical and molecular aspects of CF associated with NP. CF genotypes and clinical severity in NP(+) vs. NP(-) patients were reviewed, taking into account pulmonary function, frequency of P. aeruginosa lung infection, frequency of allergy, nutritional status, and exocrine pancreatic function. The CFTR gene was also analyzed in a patient with isolated severe NP as the unique feature of CF. This review of the literature showed a `milder` phenotype in `NP+` vs. `NP-` CF patients, contrasting with a marked association between NP and `severe` CF mutations. In addition, a complex genotype was identified, associating four heterozygous variants, namely p.Q493X (a severe mutation) on the paternal allele, and p.V562I, p.A1006E, and (TG)11(T)5 (IVS8-5T) on the maternal allele, in a case of CF presenting as isolated NP. The authors speculate that genetic/environmental factors associated with NP might attenuate the functional impact of `severe` CF mutations. The overrepresentation of CF carriers among patients with isolated NP also advocates the need for CFTR molecular screening in such populations for genetic counselling purposes.

[2,8-dihydroxyadenine nephrolithiasis: from diagnosis to therapy]

Adenine phosphoribosyltransferase (APRT, EC 2.4.2.7) deficiency is an enzymopathy of purine metabolism, which is inherited as an autosomal recessive trait. APRT is a salvage enzyme that normally catalyzes the conversion of adenine to adenosine monophosphate. APRT deficiency results in adenine accumulation with oxidation by xanthine dehydrogenase (XDH; EC 1.1.1.204) to 2,8-dihydroxyadenine (2,8-DHA) then excreted in urine. This compound is extremely insoluble and its crystallization can lead to stone formation and renal failure. The diagnosis of the disease is based on stone analysis by infrared spectroscopy or microscopic examination of urine, which may reveal typical 2,8-DHA crystals. The enzyme activity measurements in erythrocyte lysates will identify both homozygotes and heterozygotes for APRT deficiency. Molecular approach can identify mutations which are responsible of this inherited disease. Two types of deficit are commonly distinguished, depending on the level of residual APRT activity: type I, mainly observed in Caucasian subjects, in whom the enzyme activity is undetectable in homozygous patients and type II, found in Japanese patients who are able to form APRT but the enzyme activity is strikingly reduced because a low affinity for phosphoribosylpyrophosphate. The crystallization of 2,8-DHA and subsequent renal damages may be prevented with allopurinol therapy, a xanthine oxidase inhibitor. The role of the laboratory is crucial to detect APRT deficiency and to assess the efficacy of therapy, the objective being to avoid 2,8-DHA crystal formation.

Up-to-date monitoring of childhood cancer long-term survival in Europe: tumours of the sympathetic nervous system, retinoblastoma, renal and bone tumours, and soft tissue sarcomas

BACKGROUND

Prognosis for most types of childhood tumours has improved during the last few decades. In this article we estimate up-to-date period survival for less common, but important childhood malignancies in Europe.

METHODS

Using the database of the Automated Childhood Cancer Information System we calculated period estimates of 10-year survival for the 1995-1999 period for children aged 0-14 years diagnosed during 1985-1999 with tumours of the sympathetic nervous system (NS), retinoblastoma, renal tumours, bone tumours and soft tissue sarcomas in four European regions.

RESULTS

Ten-year period survival for 1995-1999 was 66% in children with tumours of the sympathetic NS, 96% for retinoblastoma, 87% for renal tumours, 58% for bone tumours and 61% for soft tissue sarcomas. The higher period estimates, as compared with cohort and complete estimates indicate recent improvement in survival for tumours of the sympathetic NS and to a lesser extent for retinoblastoma and renal tumours. Region-specific period survival estimates were lowest for Eastern Europe for renal, bone and soft tissue tumours, but not for the other two tumour groups.

CONCLUSION

There have been further improvements in the 1990s in long-term survival of children diagnosed with several malignancies, albeit to a different extent in different European regions.

Pleiotropic effects of the non-calcium phosphate binder sevelamer

The number of chronic kidney disease (CKD) patients and related adverse outcomes has dramatically increased worldwide in the past decade. Therefore, numerous experimental and clinical studies have recently addressed the underlying mechanisms, in particular the marked increase in cardiovascular mortality. Hyperphosphatemia is a major problem in these patients with advanced stage of CKD. Its control by calcium-containing phosphate binders is effective, but at the price of potentially noxious calcium overload. Sevelamer hydrochloride is a phosphate binder that offers an effective control of hyperphosphatemia as calcium-rich binders but without increase of calcium load. Beyond the control of phosphate, sevelamer seems to exert pleiotropic effects which include the correction of lipid abnormalities and the clearance of some uremic toxins.

Thyroid cancer incidence and survival among European children and adolescents (1978-1997): report from the Automated Childhood Cancer Information System project

Data on 1690 childhood and adolescent cases of thyroid cancer registered in 61 European cancer registries were extracted from the database of the Automated Childhood Cancer Information System (ACCIS) and included in analyses of incidence and survival. In 1988-1997, the age-standardised incidence rates (ASR) for children aged 0-14 years varied in European regions from 0.5 to 1.2 per million and the age-specific incidence in adolescents aged 15-19 years ranged from 4.4 to 11.0 per million. Over the age-span 0-19 years, the female to male ratio increased from 1 to around 3. Papillary thyroid cancer accounted for almost 65% of cases in children and 77% in adolescents. In the childhood population of Belarus, the ASR for 1989-1997 was 23.6 per million and the proportion of papillary tumours was 87%. No association was found between thyroid cancer risk and national dietary iodine status across 16 countries. Incidence of thyroid carcinoma among children and adolescents in Europe (excluding Belarus) increased during 1978-1997 by 3% per year, largely due to papillary carcinoma. Survival of children and adolescents was high over the entire study period and in all regions of Europe. Children with medullary carcinoma had slightly lower 5-year survival (95%, 95% CI 81-99), than those with papillary carcinoma (99%, 95% CI 95-100). More than 90% of patients survived 20 years after diagnosis. Further standardisation of diagnostic, classification and registration criteria will be fundamental for future studies of thyroid carcinomas in young people.

Quality, comparability and methods of analysis of data on childhood cancer in Europe (1978–1997): Report from the Automated Childhood Cancer Information System project

In collaboration with 62 population-based cancer registries contributing to the Automated Childhood Cancer Information System (ACCIS), we built a database to study incidence and survival of children and adolescents with cancer in Europe. We describe the methods and evaluate the quality and internal comparability of the database, by geographical region, period of registration, type of registry and other characteristics. Data on 88,465 childhood and 15,369 adolescent tumours registered during 1978-1997 were available. Geographical differences in incidence are caused partly by differences in definition of eligible cases. The observed increase in incidence rates cannot be explained by biases due to the selection of datasets for analyses, and only partially by the registration of non-malignant or multiple primary tumours. Part of the observed differences in survival between the regions may be due to variable completeness of follow-up, but most is probably explained by resource availability and organisation of care. Further standardisation of data and collection of additional variables are required so that this study may continue to yield valuable results with reliable interpretation.

[Lorraine childhood cancer registry: incidence, survival 1983-1999]

BACKGROUND

Cancer in childhood account for less than 1% of all cancers and for the second most important cause of death for children aged less than 15 years in France, injuries being the leading cause. Compared to adult cancers, childhood cancers' particularities justify to create pediatric registries. The first French population-based registry was created in Lorraine in 1983. The incidence and survival results from a 17 year-period are presented.

METHODS

In Lorraine region, all children (0-14 years) with cancer diagnosed between 1983 and 1999 were included. Crude, age-standardized (world population) and cumulative incidence rates were calculated just as overall, specific-disease and event-free survival rates, using Kaplan-Meier methods.

RESULTS

With 1086 registered cases, the crude incidence rate per million children is 132.4, the age-standardized incidence rate per million is 137.5; 1 out of every 500 children will develop cancer before the age of 15 years. The incidence of all cancers combined is slightly higher in males than in females with a M/F ratio of 1.13. For this 17 years-period, no trend in childhood cancer incidence is observed. The main cancer groups are leukemia (30.7%), brain and spinal tumors (23.2%) and lymphomas (12.9%), sympathetic nervous system tumors (7.4%), soft-tissue sarcomas (6.1%), renal tumors (5.2%), and bone tumors (5.0%). Five-year specific survival rates for all cancers combined is 71.4% [95% CI: 68.5-74.3]. The prognosis is significatively worse for the<1 year age group (55%) and for some histologic types: brain stem gliomas (27%), hepatic tumors (43%), osteosarcomas (57%), neuroblastomas (65%), rhabdomyosarcomas (55%).

DISCUSSION

Relative distribution of histologic groups, incidence and survival rates observed in Lorraine registry are compatible with the general pattern in the European Union cancer registries. The lack of significative trend in incidence unlike others country may be explained by too small numbers.

CONCLUSION

The acquired experience in developping this regional registry allowed us to create a national registry of childhood solid tumors and contribute to valid national data.

[Evaluation of lipoperoxidation in hemodialysis patients with a simple test using the "Free Oxygen Radical Monitor"]

Incidence of cardiovascular events is higher in hemodialysis (HD) patients than in general population. Oxidative stress represents a major specific risk factor of accelerated atheroma particularly in association with inflammation and malnutrition. The aim of our study is to evaluate a simple test of lipid peroxidation measurement using the "Free Oxygen Radical Monitor" (FORM) (Callegari, Italy). The results obtained in HD patients were compared to standard oxidative stress markers, such as thiobarbituric acid reacting substances, carbonyls and vitamin E in plasma, and glutathione, oxidized to reduced form ratio, in erythrocytes. In conclusion, the FORM system presents no sufficient sensibility and specificity to determine oxidative stress in HD patients.

[Clinical value of crystalluria study]

Crystalluria is a marker of urine supersaturation present in both normal and pathological conditions. Indeed, nature and characteristics of the spontaneous crystalluria are of clinical interest for detecting and following biological disorders involved in renal diseases. Method. Crystalluria examination should preferably be performed on first morning urine or fresh fasting voiding samples by polarised microscopy in a Malassez cell. Urine samples must be stored at 37 degrees C or at room temperature and examined within two hours following voiding. Results and discussion. Crystalluria should be interpreted according to various criteria: 1) chemical nature of crystals for abnormal crystals such as struvite, ammonium urate, cystine, dihydroxyadenine, xanthine or drugs; 2) crystalline phase of common chemical species as calcium oxalates, calcium phosphates and uric acids; 3) crystal morphology (calcium oxalates); 4) crystal size (calcium oxalates); 5) crystal abundance (calcium oxalates, calcium phosphates, uric acids, cystine); 6) crystal aggregation (calcium oxalates); 7) frequency of crystalluria assessed on serial first morning urine samples, a very useful tool for long-term surveillance of patients. Within calcium oxalate crystalluria, presence of whewellite is a marker of elevated oxalate concentration (urine oxalate > 0.3 mmol/L); a crystal number > 200/mm 3 is highly suggestive of heavy hyperoxaluria of genetic or absorptive origin. Predominant weddellite crystalluria is most often indicative of an excessive urine calcium concentration (> 3.8 mmol/L); a dodecahedric aspect of the crystals is a marker for heavy hypercalciuria (> 6 mmol/L) while an increased crystal size (>or= 35 microm) is indicative of simultaneous hypercalciuria and hyperoxaluria. Calculation of the global crystal volume, especially when applied to calcium oxalates or cystine, is a clinically useful tool for the monitoring of patients suffering from primary hyperoxaluria or cystinuria. Lastly, presence of crystalluria in more than 50% of serial first voided morning urine samples is in our experience the most reliable biological marker for detecting the risk of stone recurrence in lithiasic patients. Conclusion. Crystalluria examination is an essential laboratory test for detecting and following pathological conditions, which may induce renal stone disease or alter kidney function due to urine crystals.

Prenatal diagnosis of spinal muscular atrophy by genetic analysis of circulating fetal cells

Spinal muscular atrophy (SMA) has a prevalence of one in 6000 births and a one in 40 heterozygote frequency. We aimed to develop a routine test for non-invasive prenatal diagnosis. We tested blood with ISET (isolation by size of epithelial tumour or trophoblastic cells) in 12 pregnant women whose babies were at risk of SMA. Using genetic analysis of fetal cells, we identified SMA in all nine isolated from the three mothers carrying an affected child. There was no mutation in any of the 26 fetal cells isolated from the nine women with an unaffected child. Our results show that non-invasive detection of genetic diseases by the analysis of maternal blood is feasible.

Decrease of intestinal P-glycoprotein activity by 2n-propylquinoline, a new oral treatment for visceral leishmaniasis

Drugs currently available for visceral leishmaniasis treatment are potentially toxic, have to be administered by parenteral route and frequently give rise to drug resistance, due to the involvement of P-glycoproteins (P-gp) in Leishmania. The purpose of this study was to investigate a possible inhibitory effect of 2n-propylquinoline (2nPQ) on P-gp activity. 2nPQ is a new oral anti-leishmanial drug that has demonstrated its efficacy in BALB/c infected mice with Leishmania donovani [Antimicrob. Agents Chemother. 37 (1993) 859]. Rat everted gut sacs and human intestinal Caco-2 cell lines were used to study the effect of 2nPQ on P-gp activity. Our results demonstrate an inhibitory effect of 2nPQ on the P-gp activity with two P-gp substrates (rhodamine 123 and digoxin), two P-gp inhibitors (cyclosporin A and verapamil), and in two different species. Alone or associated with other active drugs, 2nPQ would be very useful to control Leishmania Multi-Drug-Resistance and intestinal P-gp in humans with kala-azar.

Absorption and efficiency of insulin after oral administration of insulin-loaded nanocapsules in diabetic rats

Poly(isobutylcyanoacrylate) nanocapsules have been shown to decrease the blood glucose level after oral administration to streptozotocin-induced diabetic fasted rats after 2 days [Diabetes 37 (1988) 246]. Yet, the absorption of insulin in the blood of rats has not been characterised. The aim of this work was to evaluate the biological activity of insulin given orally as nanocapsules. Humalog-loaded nanocapsules (50 IU/kg) were administered by gavage to streptozotocin-induced diabetic rats. Thirty minutes to 1 h after oral administration, significant levels of human insulin were detected in rat plasma. However, the concentrations were very heterogenous from one rat to another and no decrease of glycemia could be observed. In addition, parenteral injection of insulin in solution showed that high levels of the protein are necessary to decrease blood glucose concentration in diabetic rats. These concentrations were not reached after oral administration. The same dose of insulin decreased glycemia by 50% in normal rats and by only 25% in diabetics. This suggested that an insulino-resistance was developed by streptozotocin-induced diabetic rats.

[Urinary lithiasis of medical origin]

Analysis of 22,510 urinary calculi between January 1991 to July 2000 performed by infrared spectroscopy allows for separation of drug-induced urolithiasis into two categories: first, the drugs physically embedded in the stone (n = 238; 1.0 per cent), notably indinavir monohydrate (n = 126; 52.9 per cent), followed by triamterene (n = 43; 18.1 per cent), sulphonamides (n = 29; 12.2 per cent) and amorphous silica (n = 24; 10.1 per cent); second, the category of metabolic nephrolithiasis induced by drugs (n = 140; 0.6 per cent), involving mainly calcium and vitamin D supplementation (n = 56; 40.0 per cent) and carbonic anhydrase inhibitors (n = 33; 23.6 per cent). Composition of the stone depended not only on the inducer drug but also on the metabolic state of the patient. Today, drug-induced stones comprise about 1.6 per cent of all calculi in France. Physical analysis and therapeutic history recall of such patients are the keys to diagnosis. Medical care is based on drug avoidance or dose adjustment with increased diuresis and, if necessary, change in urinary pH.

Effect of chronic renal failure on the expression and function of rat intestinal P-glycoprotein in drug excretion

BACKGROUND

In chronic renal failure, the renal excretion of certain drugs is dramatically reduced. To determine whether other routes of drug elimination, such as secretion through the intestinal barrier by intestinal P-glycoprotein can be altered, we compared P-glycoprotein activity, P-glycoprotein protein content, and P-glycoprotein mRNA levels in intestine of control and chronic renal failure rats.

METHODS

Chronic renal failure was surgically induced in rats by partial (7/8) nephrectomy. After 5 weeks, intestinal transport of rhodamine 123, a P-glycoprotein substrate, was carried out using an in vitro model of everted gut sacs. P-glycoprotein protein content was quantified by enzyme-linked immunosorbent assay and P-glycoprotein mRNA expression was evaluated by semi-quantitative reverse transcriptase polymerase chain reaction.

RESULTS

A decrease of intestinal rhodamine 123 transport was observed in chronic renal failure rats, pointing to an inhibition of P-glycoprotein activity. Transport was inhibited in both sham-operated rats and rats with chronic renal failure by verapamil and cyclosporin A, but relative inhibition vs baseline was less marked in chronic renal failure than in sham-operated rats. In contrast, no significant differences in levels of P-glycoprotein protein or mRNA were observed between the two groups.

CONCLUSIONS

Intestinal secretion of rhodamine 123 is mainly mediated by P-glycoprotein. It was reduced in rats with chronic renal failure, reflecting reduced intestinal drug elimination via a decrease in P-glycoprotein transport activity rather than via protein underexpression.

[Effects of diuretic therapy on spontaneous expulsion of urinary calculi, urinary pH, and crystalluria in lithiasic patients]

OBJECTIVE

High urine volume is known to be an effective measure for preventing stone recurrence. However, only few studies have investigated its effects on crystalluria and spontaneous passage of calculi. The aim of the study was to assess the effects of high diuresis on stone expulsion and recurrence.

PATIENTS AND METHODS

219 patients were consulting for a first stone episode in Urology units in the Mostaganem area between September 1996 and December 1999. All stones were under 6 mm in size. The patients were divided in two groups: group I included 129 patients (68 males, 61 females) who agreed to be on a high water intake, at least 3 liters per day, over a two months period and to be followed periodically by crystalluria examination in the first morning urine; group II included 90 patients (63 males, 27 females) who declined diuresis advice and urine collection for crystalluria examination. First morning urine collected in patients of group I were examined before (2.95 voidings per subject) and while on diuresis course (2.84 voidings per subject). For each sample, the urine pH was measured and crystals were looked for by polarizing microscopy. Stones spontaneously passed were collected and analyzed by infrared spectroscopy. Group II represented the control group for stone passing and recurrence.

RESULTS

Crystalluria was present in 52.4% of urine samples before starting diuresis and decreased at 22.9% of urine samples on high diuresis. Mean pH value increased from 5.73 +/- 0.46 before to 6.09 +/- 0.47 (p < 10-6) while on diuresis course in males and from 5.8 +/- 0.68 to 6.24 +/- 0.66 in females (p < 10-6). The most frequent crystalline species was weddellite. Over the study period, 98 patients (76%) in group I and only 13 patients (14.4%) in group II passed stones spontaneously (p < 10-6 contre group I). No stone recurrence was observed in group I while 37.8% of patients in group II presented at least one stone recurrence (p < 10-7).

CONCLUSION

A high diuresis is an effective measure (1) to make easier the passing of stone under 6 mm in size; (2) to reduce the occurrence of crystalluria; (3) to reduce significantly, because of its favourable effect on urine pH, the formation of pH-dependent crystalline phases, thus decreasing heterogeneous nucleation process of calcium oxalate and stone recurrence.

Intestinal absorption and metabolism of chlorpheniramine enantiomers in rat

Chlorpheniramine (CPAM) is a chiral antihistaminic drug commercialized as a racemic mixture. The intestinal absorption and metabolism of CPAM have been investigated in rat using in vivo (oral and IV administration), in situ (intestinal loop model), and in vitro (everted sac model) experiments. Oral and IV administrations of 20 mg/kg of the racemic mixture show that the pharmacokinetics of CPAM are stereoselective, with higher AUCs for the (+)-S-enantiomer compared to its antipode. The monodesmethyl metabolite (DCPM) was quantifiable in blood and its pharmacokinetics are stereoselective after oral but not after IV administration. Experiments using intestinal loops and everted sacs showed that the absorption is not stereoselective and that in vivo stereoselective formation of DCPM is presumably due to stereoselective hepatic metabolism. Moreover, the in vitro and in situ absorption of CPAM are not modified by modulators of P-glycoprotein and cytochromes P450 (cyclosporin A, ketoconazole).

Effect of ethanol and ether in the prevention of calcification of bioprostheses

BACKGROUND

Lipids play a significant role in the process of calcification of bioprostheses. We assessed whether lipid extraction by ethanol, ether, or a surfactant could mitigate calcification of glutaraldehyde-treated bioprostheses.

METHODS

On 200 bovine pericardium samples pretreated with 0.6% glutaraldehyde, lipid extraction was carried out by ethanol, ether, or the tween 80 surfactant, and combinations thereof. The treated tissues were implanted subcutaneously in 50 juvenile rats for 4 and 6 months. Lipids were analyzed by Fourier transform infrared spectrophotometer and chromatography before implantation. Calcium content of implanted tissues was assessed by atomic absorption spectrometer.

RESULTS

Ethanol, ether, or surfactant did mitigate calcification. The most efficient pretreatments were the combination of ethanol and surfactant (calcium content: 15.5+/-6.8 microg/mg dry tissue after 6 months implantation) or the combination of ethanol, ether, and surfactant (13.1+/-6.2 microg/mg dry tissue) when compared with surfactant alone (42.9+/-12.7 microg/mg dry tissue).

CONCLUSIONS

Ethanol or the combination of ethanol and ether added to the currently used glutaraldehyde-surfactant treatment further mitigates calcification.

Role of oxidized low-density lipoprotein in the atherosclerosis of uremia

Lipoprotein oxidation is involved in the genesis of atherosclerosis. In chronic renal failure (CRF), oxidative stress is enhanced because of an imbalance between pro-oxidant and antioxidant systems. Oxidative modifications of low-density lipoproteins (LDLs) occur not only at the level of lipid moiety, but also of protein moiety. We have shown that oxidation of LDL by hypochlorous acid (HOCl) in vitro, reflecting increased myeloperoxidase activity in vivo, leads to modifications of apoliproteins such that the latter in turn are capable of triggering macrophage nicotinamide adenine dinucleotide phosphate-oxidase activation. These oxidative changes of LDL protein moiety, if shown to occur to a significant extent in uremic patients in vivo, may represent an important alternative pathway in the pathogenesis of atheromatous lesions.

Oxidative stress and haemodialysis: role of inflammation and duration of dialysis treatment

BACKGROUND

Oxidative stress has long been demonstrated in haemodialysis patients. However, the factors influencing their oxidative status have not been characterized extensively in these patients. Therefore, the present study was designed to investigate the influence of a large number of factors known to be associated with oxidative stress.

METHODS

In the present cross-sectional study, we determined the plasma levels of lipid and protein oxidation markers in 31 non-smoking haemodialysis patients and 18 non-smoking healthy subjects, together with various components of the antioxidant system at the plasma and erythrocyte level.

RESULTS

No influence of age, diabetes or iron overload on oxidative markers and plasma and erythrocyte antioxidant systems was detected in these haemodialysis patients. The lack of an association between iron overload and oxidative status may be related to the lower level of plasma ascorbate in haemodialysis patients, since ascorbate favours the generation of free iron from ferritin-bound iron. Interestingly, plasma C reactive protein (CRP) levels measured by highly sensitive CRP assay were correlated positively with plasma levels of thiobarbituric acid reactive substances (r=0.38, P<0.04) and negatively with plasma alpha-tocopherol levels (r=-0.46, P<0.01). Moreover, significant inverse correlations were observed between duration of dialysis treatment and plasma levels of alpha-tocopherol (r=-0.49, P<0.02) and ubiquinol (r=-0.40, P<0.05).

CONCLUSIONS

Our results suggest that inflammatory status and duration of dialysis treatment are the most important factors relating to oxidative stress in haemodialysis patients.

High serum apolipoprotein AIV levels in renal transplant recipients

BACKGROUND

Human apolipoprotein (apo) AIV might play a role in post-transplant reverse cholesterol transport, which appears to be comparable to that seen in healthy subjects. However, there may be subtle differences between healthy individuals and renal transplant recipients, given the other abnormalities of lipoprotein metabolism in the latter. Therefore, the aim of the present study was to investigate possible changes of serum apo AIV levels in renal transplant recipients, and to evaluate potential factors influencing these levels.

PATIENTS AND METHODS

Total and free serum apo AIV was determined in 36 clinically stable renal transplant recipients and in 20 sex- and age-matched healthy control subjects.

RESULTS

Mean total serum apo IV concentrations (+/- SD) were significantly higher in renal transplant recipients than in control subjects (202 +/- 102 vs 79 +/- 45 mg/l, p < 0.01). The percentage of lipoprotein-free fractions of apo AIV was comparable in both groups. The elevated total serum concentrations of apo AIV were mainly related to creatinine clearance and partially to serum triglyceride levels in renal transplant recipients.

CONCLUSION

Our data suggest that the observed elevation of serum apo AIV concentrations in renal transplant recipients is essentially related to the presence of impaired renal function.