Ureteral stricture rate after endoscopic treatments for urolithiasis and related risk factors: systematic review and meta-analysis.

PURPOSE: We aimed to accurately determine ureteral stricture (US) rates following urolithiasis treatments and their related risk factors. METHODS: We conducted a systematic review and meta-analysis following the PRISMA guidelines using databases from inception to November 2023. Studies were deemed eligible for analysis if they included ≥ 18 years old patients with urinary lithiasis (Patients) who were subjected to endoscopic treatment (Intervention) with ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), or shock wave lithotripsy (SWL) (Comparator) to assess the incidence of US (Outcome) in prospective and retrospective studies (Study design). RESULTS: A total of 43 studies were included. The pooled US rate was 1.3% post-SWL and 2.1% post-PCNL. The pooled rate of US post-URS was 1.9% but raised to 2.7% considering the last five years' studies and 4.9% if the stone was impacted. Moreover, the pooled US rate differed if follow-ups were under or over six months. Patients with proximal ureteral stone, preoperative hydronephrosis, intraoperative ureteral perforation, and impacted stones showed higher US risk post-endoscopic intervention with odds ratio of 1.6 (P = 0.05), 2.6 (P = 0.009), 7.1 (P < 0.001), and 7.47 (P = 0.003), respectively. CONCLUSIONS: The overall US rate ranges from 0.3 to 4.9%, with an increasing trend in the last few years. It is influenced by type of treatment, stone location and impaction, preoperative hydronephrosis and intraoperative perforation. Future standardized reporting and prospective and more extended follow-up studies might contribute to a better understanding of US risks related to calculi treatment.

[Acquired partial lipodystrophy. Insulin resistance, hepatic lipase activity and small and dense LDL particles]. / Lipodistrofia parcial adquirida. Resistencia insulínica, actividad lipasa hepática y partículas LDL pequeñas y densas.

Partial lipodystrophy (PLD) is an infrequent condition characterized by symmetric loss of subcutaneous adipose tissue in the upper or lower part of the body, although occasionally it affects only the extremities. In all cases it appears along with acantosis nigricans (AN), insulin resistance and impairment in the metabolism of lipids and carbohydrates. The case depicted pertains to a 49 year old female with no family history involving loss of adipose tissue in face and upper body. No fat in lower part of body was observed. The patient showed facial thinning at age 8, AN at 11 and gestational diabetes during her fourth pregnancy at 33. At present, the patient presents severe hyperglycemia and hyperinsulinemia with a marked insulin resistance. Type IV hyperlipoproteinemia (OMS), declined C-HDL and Apo A1 and low C-LDL but with a high proportion of small and dense LDL particles were present. Non esterified fatty acids were high. Lipoprotein lipase and hepatic lipase activities are in the lower limit and increased respectively. Fraction C3 of the complement was diminished. No mutations were observed either in codons 170, 809 and 972 of the IRS-1 receptor or in codon 276 of the adrenergic beta 2 gene.

Intestinal passive absorption of water-soluble compounds by sparrows: effect of molecular size and luminal nutrients.

We tested predictions that: (1) absorption of water-soluble probes decreases with increasing molecular size, consistent with movement through effective pores in epithelia, and (2) absorption of probes is enhanced when measured in the presence of luminal nutrients, as predicted for paracellular solvent drag. Probes (L-arabinose, L-rhamnose, perseitol, lactulose; MW 150.1-342.3 Da) were gavaged in nonanesthetized House sparrows ( Passer domesticus), or injected into the pectoralis, and serially measured in plasma. Bioavailability was calculated as F=AUC by gavage/AUC by injection, where AUC is the area under the curve of plasma probe concentration vs. time. Consistent with predictions, F declined with probe size by 75% from the smallest to the largest probe, and absorption of probes increased by 40% in the presence of luminal glucose or food compared to a mannitol control. Absorption of water-soluble probes by sparrows is much higher than in humans, which is much higher than in rats. These differences seem mainly attributable to differences in paracellular solvent flux and less to differences in effective paracellular pore size.

HDL oxidability and its protective effect against LDL oxidation in Type 2 diabetic patients.

Low density lipoprotein (LDL) oxidation is a crucial step in the atherosclerotic process. High density lipoprotein (HDL)-associated enzymes such as paraoxonase could exert a protective effect on LDL oxidation in the arterial wall, an effect which could be impaired in Type 2 diabetes mellitus (T2DM). We studied copper-induced oxidation in LDL and HDL isolated from 17 T2DM patients with fair glycaemic control and HDL-cholesterol within normal range and 17 healthy normolipidaemic control subjects. To evaluate the effect of HDL on LDL oxidation in diabetic and control subjects, we assessed copper-induced oxidation in HDL/LDL mixtures, with each lipoprotein isolated from the same subject. Relationships with HDL chemical composition, alpha-tocopherol content and serum paraoxonase activity were investigated. Oxidation was promoted by lipoprotein incubation with copper and then thiobarbituric acid reactive substances (TBARS), conjugated diene production and electrophoretic mobility in agarose gel were measured. In T2DM subjects HDL oxidation was higher than in controls. However, HDL from diabetics was as effective as control HDL to inhibit LDL oxidation. Neither HDL chemical composition nor serum paraoxonase activity showed any difference as compared to control subjects. In contrast, HDL from T2DM subjects showed a higher alpha-tocopherol content which positively correlated with HDL oxidability. Paraoxonase activity positively and strongly correlated with HDL inhibitory effect on LDL oxidation in patients and controls belonging to the heterozygous activity phenotype. Besides, LDL oxidability showed no differences between patients and controls. These results suggest that fairly-controlled T2DM patients with HDL-cholesterol levels within normal range show: 1) normal HDL ability to inhibit LDL oxidation related to normal paraoxonase activity; 2) higher HDL oxidability in spite of its high alpha-tocopherol content, which could favour tocopherol-mediated peroxidation and 3) normal LDL oxidability possibly due to the lack of significant lipoprotein structural alterations.

Lipodistrofia parcial adquirida. Resistencia insulínica, actividad lipasa hepática y partículas LDL pequeñas y densas. / [Acquired partial lipodystrophy. Insulin resistance, hepatic lipase activity and small and dense LDL particles]

Partial lipodystrophy (PLD) is an infrequent condition characterized by symmetric loss of subcutaneous adipose tissue in the upper or lower part of the body, although occasionally it affects only the extremities. In all cases it appears along with acantosis nigricans (AN), insulin resistance and impairment in the metabolism of lipids and carbohydrates. The case depicted pertains to a 49 year old female with no family history involving loss of adipose tissue in face and upper body. No fat in lower part of body was observed. The patient showed facial thinning at age 8, AN at 11 and gestational diabetes during her fourth pregnancy at 33. At present, the patient presents severe hyperglycemia and hyperinsulinemia with a marked insulin resistance. Type IV hyperlipoproteinemia (OMS), declined C-HDL and Apo A1 and low C-LDL but with a high proportion of small and dense LDL particles were present. Non esterified fatty acids were high. Lipoprotein lipase and hepatic lipase activities are in the lower limit and increased respectively. Fraction C3 of the complement was diminished. No mutations were observed either in codons 170, 809 and 972 of the IRS-1 receptor or in codon 276 of the adrenergic beta 2 gene.