Toward a metabolic theory of catchments: Scaling of water and carbon fluxes with size.

Allometric scaling relations are widely used to link biological processes to body size in nature. Several studies have shown that such scaling laws hold also for natural ecosystems, including individual trees and forests, riverine metabolism, and river network organization. However, the derivation of scaling laws for catchment-scale water and carbon fluxes has not been achieved so far. Here, we focus on scaling relations of catchment green metabolism, defined as the set of ecohydrological and biogeochemical processes through which vegetation assemblages in catchments maintain their structure and react to the surrounding environment. By revising existing plant size-density relationships and integrating them across large-scale domains, we show that the ecohydrological fluxes occurring at the catchment scale are invariant with respect to the above-ground vegetation biomass per unit area of the basin, while they scale linearly with catchment size. We thus demonstrate that the sublinear scaling of plant metabolism results in an isometric scaling at catchment and regional scales. Deviations from such predictions are further shown to collapse onto a common distribution, thus incorporating natural fluctuations due to resource limitations into a generalized scaling theory. Results from scaling arguments are supported by hyperresolution ecohydrological simulations and remote sensing observations.

How Covid-19 changed the epidemiology of febrile urinary tract infections in children in the emergency department during the first outbreak.

BACKGROUND: The first Covid-19 pandemic affected the epidemiology of several diseases. A general reduction in the emergency department (ED) accesses was observed during this period, both in adult and pediatric contexts. METHODS: This retrospective study was conducted on the behalf of the Italian Society of Pediatric Nephrology (SINePe) in 17 Italian pediatric EDs in March and April 2020, comparing them with data from the same periods in 2018 and 2019. The total number of pediatric (age 0-18 years) ED visits, the number of febrile urinary tract infection (UTI) diagnoses, and clinical and laboratory parameters were retrospectively collected. RESULTS: The total number of febrile UTI diagnoses was 339 (73 in 2020, 140 in 2019, and 126 in 2018). During the first Covid-19 pandemic, the total number of ED visits decreased by 75.1%, the total number of febrile UTI diagnoses by 45.1%, with an increase in the UTI diagnosis rate (+ 121.7%). The data collected revealed an increased rate of patients with two or more days of fever before admission (p = 0.02), a significant increase in hospitalization rate (+ 17.5%, p = 0.008) and also in values of C reactive protein (CRP) (p = 0.006). In 2020, intravenous antibiotics use was significantly higher than in 2018 and 2019 (+ 15%, p = 0.025). Urine cultures showed higher Pseudomonas aeruginosa and Enterococcus faecalis percentages and lower rates of Escherichia coli (p = 0.02). CONCLUSIONS: The first wave of the Covid-19 pandemic had an essential impact on managing febrile UTIs in the ED, causing an absolute reduction of cases referring to the ED but with higher clinical severity. Children with febrile UTI were more severely ill than the previous two years, probably due to delayed access caused by the fear of potential hospital-acquired Sars-Cov-2 infection. The possible increase in consequent kidney scarring in this population should be considered.

Rayleigh-Bénard convection with thermal boundary inhomogeneities.

Rayleigh-Bénard convection with nonhomogeneous thermal boundaries (sinusoidal temperature patterns set in-phase at the top and bottom plates) is numerically studied in three- and two-dimensional domains. Two spatial convective scales occur: the one due to the self-organized clustering of plumes-which is known to appear in homogeneous conditions-and the scale induced by the boundary heterogeneities. The latter drives the convection patterning, both in 3D and 2D, when the wavelength of the perturbation is comparable with the self-organized one.

The impact of perinatal urinoma formation on renal function: our experience and review of the literature.

INTRODUCTION: A urinoma is a fluid mass consisting of extravasated urine in the perirenal space. Its impact on renal function was analysed. METHODS: All cases of prenatal and neonatal urinoma reported in the literature were analysed as well as two cases recently observed in our department. RESULTS: A review of all prenatally diagnosed urinomas revealed 25 cases, for a total of 30 renal units. The cause of obstruction was: lower urinary tract (LUT) obstruction in 16 cases (62.5%), upper urinary tract (UUT) obstruction in seven cases (29.5%) and unknown in two cases (8%). A preserved renal function was found in only 30% of all cases. Furthermore, prognosis for renal function was better in posterior urethral valve (PUV) patients than in uretero-pelvic junction obstruction (UPJO) patients. In addition, we analysed 35 published cases of urinoma with a neonatal onset, without prenatal diagnosis, and secondary to LUT obstruction in 27 cases (77%), UUT obstruction in seven cases (20%), while the underlying cause was unknown in one cases (3%). A preserved renal function was observed in 84% of cases with UUT obstruction and in 80% of cases presenting a LUT obstruction. CONCLUSIONS: Prognosis concerning renal function seems to be mainly related to two factors: age at presentation and underlying diagnosis. Decompression of the urinary tract by urine extravasation produces the best results in terms of preservation of the renal function in LUT obstruction (75% in prenatal and 84% in postnatal cases); UUT obstruction however is associated with a good prognosis in the neonatal period (80% of preserved renal function) but with a severe impairment (only 20% of preserved renal function) in prenatally detected cases.

Ullrich-Turner Syndrome and Tumor Risk: Is There Another Chance to Early Gonadectomy in Positive TSPY and SRY Patients?

The presence of the Y chromosome in the karyotype of patients with disorders of sex differentiation is significantly associated with an increased risk to develop specific types of malignancies, predominantly type II germ cell tumors (GCTs). Gonadoblastoma in the gonads without an obvious testicular differentiation and intratubular germ cell neoplasia of unclassified type in testicular tissue are the precursor lesions of most GCTs. Gonadal dysgenesis, the characteristic feature of Ullrich-Turner syndrome (UTS), further contributes to increase this tumor risk. The reported incidence of Y chromosome material in UTS is 6 to 8% and in these cases an early gonadectomy is strongly recommended to prevent the risk of a malignancy. The aim of this work was to retrospectively analyze the clinical outcome and the histopathological and cytogenetic findings of our UTS patients who underwent gonadectomy to establish strict selection criteria aimed at promoting an organ-sparing surgery.

Changing concepts in microsurgical pediatric varicocelectomy: is retroperitoneal approach better than subinguinal one?

PURPOSE: To compare and to assess two different microsurgical "lymphatic-sparing" techniques (subinguinal/inguinal vs. retroperitoneal) used for the treatment of a pediatric and adolescent varicocele in terms of success rate, complications and mean operative time. MATERIALS AND METHODS: A retrospective study included 54 consecutive patients affected by a varicocele and treated with a microsurgical (loupes--operating microscope) magnification. Thirty-four out of 54 (group 1) underwent subinguinal ligation with the help of loupes magnification (× 3); 20 out of 54 (group 2) underwent retroperitoneal (Palomo like) ligation with preservation of lymphatics and with the help of an operating microscope (× 6 to 10). The two groups were homogeneous in terms of mean age, clinical and color Doppler ultrasound grade of disease. Pre- and post-operative testicular volume was measured in all cases. All the procedures were performed under general anesthesia and in an outpatient basis. RESULTS: Mean post-operative follow-up time was 23.6 months. In group 1 we observed 3 (8.8%) early complications (wound's infection, transient hydrocele), 2 (5.8%) recurrences and 1 (2.9%) major complication (atrophy of the testis). Mean operative time was 45 +/- 6 min. In group 2 we did not observe complications and/or varicocele recurrence and mean operative time was 38 +/- 7 min. Comparison of mean operative time between the two groups resulted statistically significant differences (P < .05) such as the difference in testicular "catch-up" growth volume between pre- and post-operative evaluations. CONCLUSION: Retroperitoneal microsurgical "lymphatic-sparing" varicocelectomy is safe and effective method. In our experience, it is preferable, in the pediatric and adolescent patient, to the subinguinal/inguinal approach in terms of success rate, complications and operative time duration. 

Cobb's collar: a rare cause of urinary retention.

Cobb's collar is a membranous stricture of the bulbar urethra, often misdiagnosed, potentially leading to acute urinary retention, upper urinary tract dilations, enuresis, infectious diseases, poor streaming and haematuria. A 14-year-old boy with a history of previous hospitalisations came to our attention. A Cobb's collar was diagnosed and successfully managed with a videoendoscopic one-step approach. Although extremely uncommon, paediatric urologists must be aware of this congenital anomaly. A correct and timely diagnosis and endoscopic management may affect positively the clinical onset of these patients avoiding major urethral surgery and preserving renal and bladder function.

Management and follow-up of pediatric asymptomatic testicular microlithiasis: are we doing it well?

PURPOSE: To define timing and methods for a balanced follow-up of testicular microlithiasis (TM) in pediatric age. MATERIALS AND METHODS: We retrospectively reviewed medical records of 21 pediatric asymptomatic patients (42 testicular units) diagnosed with TM and without associated risk factors. Microliths were found bilaterally on ultrasonography in all the patients. Distribution of microliths (focal or diffuse) inside the parenchyma was evaluated as well as its eventual variation over time. Every six months, each patient underwent clinical and ultrasonography evaluation, as well as serum chemistry markers (α-fetoprotein and ß-human chorionic gonadotropin) measurement to detect potential malignancy. In the interval between the follow-ups, parents and/or patients themselves were asked to control eventual enlargement of the gonads or scrotal swelling. Testicular biopsy was not performed in any of our subjects. RESULTS: Of 21 patients, 6 had unilateral undescended testis, 4 varicocele, and 1 patent processus vaginalis with scrotal swelling while 10 patients did not show associated anomalies. The distribution pattern of microliths on ultrasonography remained unchanged in all follow-ups in every patient, showing a predominance of diffuse pattern in the undescended testis series. Tumor markers remained within normal limits. In no subject, we observed a shift toward a malignant condition. CONCLUSION: In the pediatric population with an incidentally diagnosed TM and without any associated risk factor, a slight follow-up is suggested, consisting of clinical evaluation every 6 months, without any justifiable recommendation to perform a testis biopsy and a measurement of serum tumor markers.

Endoscopic management of a type IV syringocele causing massive perirenal urinoma in an infant.

The finding of a urinoma in the fetal and neonatal period is almost always related to an obstruction distal to the collection itself. Syringocele is a congenital or acquired dilation of a bulbourethral Cowper's gland. An exceedingly rare case of neonatal anterior urethral obstruction caused by a syringocele and manifesting itself with a dramatic clinical onset is presented. Clinical and radiologic findings are discussed and minimally invasive therapeutic strategies emphasized.