Development of real-time PCR method for the detection and the quantification of a new endogenous reference gene in sugar beet "Beta vulgaris L.": GMO application.

KEY MESSAGE : Here, we describe a new developed quantitative real-time PCR method for the detection and quantification of a new specific endogenous reference gene used in GMO analysis. The key requirement of this study was the identification of a new reference gene used for the differentiation of the four genomic sections of the sugar beet (Beta vulgaris L.) (Beta, Corrollinae, Nanae and Procumbentes) suitable for quantification of genetically modified sugar beet. A specific qualitative polymerase chain reaction (PCR) assay was designed to detect the sugar beet amplifying a region of the adenylate transporter (ant) gene only from the species of the genomic section I of the genus Beta (cultivated and wild relatives) and showing negative PCR results for 7 species of the 3 other sections, 8 related species and 20 non-sugar beet plants. The sensitivity of the assay was 15 haploid genome copies (HGC). A quantitative real-time polymerase chain reaction (QRT-PCR) assay was also performed, having high linearity (R (2) > 0.994) over sugar beet standard concentrations ranging from 20,000 to 10 HGC of the sugar beet DNA per PCR. The QRT-PCR assay described in this study was specific and more sensitive for sugar beet quantification compared to the validated test previously reported in the European Reference Laboratory. This assay is suitable for GMO quantification in routine analysis from a wide variety of matrices.

[Epidemiological changes of paediatric urolithiasis in Tunisia]. / Evolution épidémiologique de la lithiase urinaire infantile en Tunisie.

BACKGROUND: The clinical and biological characteristics of urolithiasis in children are still evolving in our country. Since the eighties no study has been conducted to determine incidence of urolithiasis in Tunisia. AIM: To define the current status of urolithiasis in Tunisian children. METHODS: The records of 414 children with urolithiasis treated between 1983 and 2007 were found in a multi-centric study which took into consideration to age, sex, and history diagnosis and physical, laboratory, and radiologic findings. Clinical and biological date were performed in 344 cases. Stone analysis was performed by spectrophotometry. RESULTS: The incidence of paediatric urolithiasis has steadily decreased from 0.7/ 10 000 of the child population / year in 1991-1994 to 0.1 cases/10 000 children/ year in 2007. There was a continuous decrease in bladder stone over the past 25 years (47.1% in 1982-1986 Vs 10.2% in 2002-2007). Stones were homogeneous in 31.4% of cases. The main component was calcium oxalate stones in 36.4% of the cases. Since the eighties the increase of oxalates stones (15.6% in eighties Vs 51.5% actually) were with depends to purines and struvite stones. CONCLUSION: Epidemiologic characteristics of the urinary lithiasis (sex, age, localization and composition) have changed in Tunisia, due to the the improvements of standard of living. The occidentalization of the nutritional practices and the receding of the culinary traditions gave birth to new risks of urolithiasis characterized by the emergence of calcium oxalate stones.

Changes in urinary stone composition in the Tunisian population: a retrospective study of 1,301 cases.

BACKGROUND: Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients' age. METHODS: We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone. RESULTS: The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults. CONCLUSIONS: The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.

Kidney stones in children and teenagers in the central coast region of Tunisia.

OBJECTIVE: Since 1980s, the clinical and biological characteristics of urolithiasis in Tunisian children have continuously evolved. This retrospective study defines the current status of urolithiasis among children and adolescents in Tunisia. METHODS: We retrospectively reviewed the records of 310 children and adolescents (age: 3 months - 19 years) between 2003 and 2010, holding urolithiasis. A first-line metabolic, urine and plasma work-up was performed in all patients. Physical and chemical analysis of the stones was performed respectively by stereomicroscopy and infrared spectroscopy. Statistical analysis of the results was performed with SPSS 11.0 software. The Chi-square test was used for comparison of percentages. FINDINGS: Our study shows a male predominance of urolithiasis with a sex ratio of 1.5. Stones were located in the upper urinary tract in 70.7% of cases. Calcium oxalate was the predominant constituent in 52.6% of stones. There was an increasing prevalence of calcium oxalate stones according to age in both genders (48.6% in infants vs 68.5% in teenagers (P<0.01)). Struvite was more frequent in patients aged 2-9 years (P<0.02) and significantly more prevalent in boys than in girls (P<0.001). Ammonium urate stones were observed in 14.2% and were more frequent in infants. CONCLUSION: Our results emphasize a high percentage of calcium oxalate stones and a low percentage of struvite stones. The persistence of urate stones reflects the particular eating habits and the infectious risk factors. The patient's age is an important factor that must be taken into account during etiopathogenic work-up.

Nutritional aspects of idiopathic nephrolithiasis in Tunisian children.

OBJECTIVE: We evaluated the metabolic and the nutritional aspects of 134 urolithiasic children, in order to outline the risk factors that contribute to idiopathic stone formation in children. MATERIAL AND METHODS: In this prospective study 134 children (56 females, 78 males) with renal calculi were evaluated. The age of the patients ranged 6 months to 16 years. A dietary survey was performed on every child. All patients were investigated with respect to stone localization, serum and urine risk factors. Statistical analysis of data was carried out using software SPSS 11.0 for Windows. Statistical significance was determined using chi-square test. RESULTS: Hypercalciuria was the commonest risk factor detected in this group (28.3%). A decrease of water intake was noted in all age group specially in the rural area (549.6 vs 1150.6 ml/day), and an increase in animal protein intake in 17 cases (mean 1.9 g/kg). In addition, increased intake of starchy foods and food with high oxalate content (sorgum) was observed in our 10-16 years group (51%). Calcium oxalate monohydrate represents the principal component of idiopathic stone (58.2%), which is more frequent in children (68%) than infants (51.7%) (P < 0.02). CONCLUSIONS: The high frequency of idiopathic urolithiasis highlights the influence of dietary habit in stone formers in our country. The increase in calcium oxalate stones in school-age children confirms the change in the etiology of urolithiasis according to age.

Urinary stone composition in pediatric patients: a retrospective study of 205 cases.

BACKGROUND: Stone composition has changed substantially over the past decades in developed countries. We studied urinary stone composition in Tunisian children. METHODS: We studied 205 children ranging from 3 months to 16 years old age and who were diagnosed as having urinary stones (122 boys and 83 girls). Stone analysis was performed respectively using a stereomicroscope and by infrared spectroscopy to determine, respectively, the morphological type and molecular composition of each. RESULTS: Of 205 stones analysed, 77 (37.5%) were composed of a single constituent. Calcium oxalate (CaOx) stone were predominant, being a constituent of 54.7% of stones, followed by calcium phosphate and purines; 14.6% of cases. Calcium oxalate monohydrate was more frequently seen in girls (p < 0.01), while struvite was more common in boys (p < 0.001). Teenagers were more affected by whewellite stones compared with infants (p < 0.05). Purine stones were predominant in 20% of cases, but its prevalence decreased with age. CONCLUSIONS: The increase in calcium oxalate stones in school age children and the decrease of struvite and purines stones confirm the change in the etiology of urolithiasis with respect to age.

Paediatric urolithiasis in central coast region of Tunisia: changes in stone composition according to age and gender.

OBJECTIVE: Studies evaluating the influence of age and gender on the distribution of the various types of paediatric urinary calculi are scarce. Aim of our study was to high-light the modification of epidemiological characteristics of this pathology depending on patients' age and gender. PATIENTS AND METHODS: We present the results of a study based on 205 calculi (from 122 boys and 83 girls) analyzed by infrared spectroscopy between 1993 and 2007. 54.6% of the patients were under 5 years. RESULTS: Calcium oxalate (CaOx) was the predominant constituent in 54.7% of stones, followed by calcium phosphate and ammonium urate (14.6% each). We found a male preponderance for struvite stones (12.3% vs 1.2%), and an increasing prevalence of calcium oxalate stones with age (42.9% in infants vs 59.3% in older children). Purines stones were observed in 20% of cases, but their prevalence decreases with age (28.6% in infants vs 18.5% in old children). CONCLUSION: The increase of calcium oxalate stone rate in school age children and the decrease of purines stones confirm the change on the etiology of urolithiasis according to age.

Paediatric urolithiasis in central coast region of Tunisia: clinical characteristics.

OBJECTIVE: To show an outline of the clinical and biological characteristics of paediatric urolithiasis among Tunisian children in the coast region. PATIENTS AND METHODS: This retrospective study included 168 children under the age of 16 years presented with urinary stones (100 boys and 68 girls). Patients were reviewed in a multi-centric study with regard to age at diagnosis, sex, history, and physical, laboratory, and radiologic findings. The physical and chemical analysis of stones was carried out respectively by a stereomicroscope and by infra-red spectroscopy. RESULTS: The sex ratio was 1.47. The clinical presentation of this pathology was dominated by abdominal pain (28%), hematuria (25.6%), dysuria (16.7%) and urinary tract infection (14.3%). Stones were located in the upper urinary tract in 75.6% of cases. Of the urine cultures, 14.3% were positive. Whewellite was more frequent in children stones than in infants (p < 0.05) and was the main component in 46.4% of stone section and 55.4% in stone surface. CONCLUSION: The male prevalence of paediatric urolithiasis is progressively decreasing in Tunisia. The epidemiological profile of renal stones in our country has changed towards a predominance of calcium oxalate stone and upper tract location.

Changes in stone composition according to age in Tunisian pediatric patients.

The epidemiology of renal stones has changed all over the world toward a predominance of calcium oxalate stones. However, studies evaluating the influence of age and gender on the distribution of the various types of urinary calculi are scarce. We will present the results of a study based on 205 calculi (from 122 boys and 83 girls) analyzed by infrared spectroscopy between 1993 and 2007. 90% of stones were collected by surgery, whereas only 6% by spontaneous passage. The biological exploration was performed in only 126 cases. Etiology was metabolic in 13.5%. 10.7% of stones were infectious, 13.1% were endemic and 54.9% were idiopathic. 7.8% were secondary to urinary stasis with malformation but no infection. Calcium oxalate (CaOx) was the predominant constituent in 54.7% of stones, followed by calcium phosphate and purines 14.6% in each of the cases. We found an increasing prevalence of calcium oxalate stones with age in both genders (42.9% in infant vs. 59.3% in child) (P < 0.05). Struvite stones were more frequent in infant than children. Purine stones were predominant in 20% of cases, but its prevalence decreases with age. The increase in calcium oxalate stone in school age children and the decrease in struvite and purine stones confirm the change on the etiology of urolithiasis according to age.

Urolithiasis in Tunisian children: a study of 100 cases.

The aim of this study is to assess the clinical and biological characteristics of renal stone disease among children living in the coastal region of Tunisia. This retrospective multi-center study included 100 children under the age of 16 years, who presented with urinary stones. The patients' charts were reviewed with regard to age at diagnosis, sex, history and physical examination as well as laboratory and radiologic findings. Stone analysis was performed by infrared spectrophotometry. The male/female sex ratio was 1.5 to 1. The clinical presentation of this pathology was dominated by dysuria. Stones were located in the upper urinary tract in 76 cases (76%). A total of 13% of the study subjects had positive urine cultures. Metabolic investigations were performed in all patients and were normal in 80 cases. Whewellite (calcium oxalate) was found in 77 stones (77.0%). Stone section was made of whewellite in 69.0% of cases and ammonium urate in 47.0%. Struvite stones were more frequently seen in the lower urinary tract. Our study suggests that the epidemiological profile of renal stones in Tunisia has changed towards a predominance of calcium oxalate stones and upper tract location. Also, the male predominance of pediatric urolithiasis is becoming less obvious in Tunisia.

Paediatric renal stone disease in Tunisia: a 12 years experience.

OBJECTIVES: International studies may not reflect the real changes of stone disease in our own country. In this retrospective work, we describe the evolution of this pathology in Tunisia during the last 12 years. MATERIALS AND METHODS: The records of 133 children with urolithiasis treated in Tunisia between 1994 and 2006 were reviewed. The physical and chemical analysis of stones was carried out respectively by a stereomicroscope and by infra-red spectroscopy and the epidemiologic data were collected. RESULTS: The male prevalence of this pathology is progressively declining. The male to female ratio, passed from 1.7 in the 1994-97 period to 1.5 in 2006. Upper urinary tract was most frequently affected by this pathology. Over the last 12 year period urinary tract infection was in continuous increase and currently reaches 50% being 21.9% in 1994. This explains the increasing frequency of struvite stones which passed from 15.6% in 1994 to 37.5% in 2006. Ammonium urate stones became more frequent in the last few years being the main component in 25% of cases (12.5% in 1994-97). Calcium oxalate monohydrate remains the most frequent stone component even if its frequency fell (59.4% in 1994 and 12.5% in 2006) in favour of the increase of phosphatic and phospho-calcic stones. CONCLUSION: The rise in the frequency of struvite and ammonium urate stone reflects an increase in the infectious risk factors in our country.

[Urolithiasis in children in Tunisia: current features based on a series of 104 cases]. / La lithiase urinaire de l'enfant en Tunisie. Aspects actuels a propos de 104 cas.

UNLABELLED: The clinical and laboratory characteristics of urolithiasis in Tunisian children have evolved continuously since the 1980s. This retrospective study defines the current status of urolithiasis in children in Tunisia. PATIENTS AND METHODS: All 104 children (age: 8-192 months) of our series were hospitalized for urolithiasis. A first-line metabolic, urine and plasma work-up was performed in 96 patients. Physical and chemical analysis of the stones was performed by stereomicroscopy and infrared spectroscopy, respectively. Statistical analysis of the results was performed with SPSS 11.0 software. The Chi-square test was used for comparison of percentages. RESULTS: Our study shows a male predominance of urolithiasis with a sex ratio of 1.53. The clinical features were dominated by urinary tract infections (28.8%). Stones were situated in the upper tract in 75% of cases and the lower tract in 25% of cases. Urine culture was positive in 15 patients. Identification of the crystalline composition showed that whewellite was the most frequent crystalline species in children (80.0%) and infants (57.1%). Ammonium acid urate was more frequent in infants. CONCLUSION: In this study, we observed changes in the epidemiological characteristics (bladder stones and infection stones) of urolithiasis in children over the last decade in Tunisia. The patient's age is an important factor that must be taken into account during aetiopathogenic work-up.