Endothelial-Derived miR-17∼92 Promotes Angiogenesis to Protect against Renal Ischemia-Reperfusion Injury

BackgroundDamage to the renal microvasculature is a hallmark of renal ischemia-reperfusion injury (IRI)–mediated AKI. The miR-17∼92 miRNA cluster (encoding miR-17, -18a, -19a, -20a, -19b-1, and -92a-1) regulates angiogenesis in multiple settings, but no definitive role in renal endothelium during AKI pathogenesis has been established.MethodsAntibodies bound to magnetic beads were utilized to selectively enrich for renal endothelial cells from mice. Endothelial-specific miR-17∼92 knockout (miR-17∼92^endo−/−) mice were generated and given renal IRI. Mice were monitored for the development of AKI using serum chemistries and histology and for renal blood flow using magnetic resonance imaging (MRI) and laser Doppler imaging. Mice were treated with miRNA mimics during renal IRI, and therapeutic efficacies were evaluated.ResultsmiR-17, -18a, -20a, -19b, and pri–miR-17∼92 are dynamically regulated in renal endothelial cells after renal IRI. miR-17∼92^endo−/− exacerbates renal IRI in male and female mice. Specifically, miR-17∼92^endo−/− promotes renal tubular injury, reduces renal blood flow, promotes microvascular rarefaction, increases renal oxidative stress, and promotes macrophage infiltration to injured kidneys. The potent antiangiogenic factor thrombospondin 1 (TSP1) is highly expressed in renal endothelium in miR-17∼92^endo−/− after renal IRI and is a target of miR-18a and miR-19a/b. miR-17∼92 is critical in the angiogenic response after renal IRI, which treatment with miR-18a and miR-19b mimics can mitigate.ConclusionsThese data suggest that endothelial-derived miR-17∼92 stimulates a reparative response in damaged renal vasculature during renal IRI by regulating angiogenic pathways.     

Production and characterization of monoclonal antibodies to guinea pig lymphoid differentiation antigens

We have prepared 2 mouse monoclonal antibodies which react with differentiation antigens on guinea pig lymphoid cells. Monoclone 5AB2 recognizes an antigen expressed on both T and B lymphocytes and absent on macrophages. It has proven useful in the preparation of populations of antigen presenting cells which are free of T and B lymphocytes. The second monoclonal, 8BE6, is specific for peripheral T cells and 10% of thymocytes. It reacts with a 68,000 dalton molecule which is also expressed on the guinea pig B cell leukemia, EN-L2C. 8BE6 has proven to be lytic for peripheral T cells in the presence of rabbit complement and has been used to deplete T cells from heterogenous cell populations.     

Radioimaging of human glioma xenografts with 123I labeled monoclonal antibody G-22 against glioma-associated antigen

Summary Monoclonal antibody (MCA) G-22 is directed against a human glioma-associated surface antigen. Its availability for the radioimmunodetection of human glioma was analyzed by utilizing the xenografts in athymic mice. Nude mice with subcutaneous grafts of U251-MG or U251-SP glioma received intravenous administration of ¹²³I or ¹³¹I labeled F(ab)2 fragment or whole immunoglobulin. Results of radioimaging revealed that ¹²³I-labeled antibody was better than the ¹³¹I-labeled. It was also noted that administration of ¹²³I-labeled F(ab)2 fragment of G-22 MCA enabled the imaging of human glioma xenografts weighing 80–650 mg after 48 hours. When biodistribution of ¹²³I MCA was compared between G-22 and control antibodies, the percentages of dose/g in tumors were 5.228–1.799 at 30 hours and 4.112–1.132 at 48 hours with G-22 and they were 4.164–1.248 and 0.314–0.142 with control. The tumor/blood ratio until 72 hours after injection was constantly above 1 with G-22 and less than 1 with control antibody. These results indicate the potential usefulness of G-22 MCA for the radioimmunodetection of human gliomas.     

Efficacy of an echo contrast agent, SH/TA-508, in color doppler sonography of mass lesions in urology

We performed a clinical phase III study with a galactosebased ecoo contrast agent, SH/TA-508, to evaluate its efficacy, safety, and usefulness for mass lesions in urology. SH/TA-508 was prepared as a suspension containing stabilized micro-air bubbles by adding water for injection just before use. SH/TA-508 was administered into the antecubital vein at an initial dose of 300 mg/ml × 5 ml followed by higher doses of 400 mg/ml × 4 ml, 300 mg/ ml × 10 ml or 400 mg/ml × 8 ml when a sufficient effect was not obtained. Efficacy was evaluated by color Doppler signal enhancement, the duration of blood flow signal enhancement, and improvement of diagnostic capacity. Fifty-nine patients with mass lesions in the kidney, prostate, testis, adrenal gland, and bladder were enrolled in the study. Up to the third dose the cumulative efficacy rates (≥2+) of color Doppler signal enhancement and duration of blood flow signal enhancement were 92% and 87%, respectively. Consequently, diagnostic capacity in 76% of the patients was remarkably improved. A light transient angialgia occurred in one patient but no other clinically significant changes were observed. It was confirmed that SH/TA-508 is a safe echo contrast agent that offers satisfactory color Doppler signal enhancement in the urologic organs mentioned above.     

Sodium azide: a review of biological effects and case reports

This report reviews the biological effects and case reports of suicidal or accidental ingestion of, and occupational exposure to sodium azide. Ingested doses of sodium azide were estimated for the 6 survival and 4 fatal cases studied. The lowest dose among survival cases was 5-10 mg. The patient reported headache, sweating, and faintness within approximately 5 minutes of ingestion. Four victims ingested 20 to 40 mg and recovered within 2 hours. However, a man who took 80 mg reported chest pain for 6 months after ingestion. The smallest doses among fatal cases were 0.7-0.8 g for women and 1.2-2 g for men. All victims suffered from hypotension, tachycardia, hyperventilation, diaphoresis, vomiting, nausea, and diarrhea. There is no antidote for sodium azide. Detoxicants for cyanide such as sodium nitrite or thiosulfate were tried, but were unfortunately, ineffective. Sodium nitrite may worsen the hypotension caused by sodium azide, and is not recommended. Occupational exposure to sodium azide is thought to be common, however, fatal exposure is rare. NIOSH "Recommended Exposure Limits" for sodium azide is 0.3 mg/m3.     

How to stabilize a single level lesion of degenerative lumbar spondylolisthesis

The purpose of this study was to compare the success rate of bony fusion and the clinical results of rigid instrumentation, nonrigid instrumentation, and no instrumentation for a single level lesion for degenerative lumbar spondylolisthesis. Thirty-three patients with degenerative spondylolisthesis of L4 who had undergone posterior decompression and posterolateral fusion with autogenous bone graft that included the facet joints had a single level stabilization with a newly designed syndesmoplasty using Leeds-Keio artificial ligaments (Group Leeds-Keio-nonrigid). Thirty-four patients with degenerative spondylolisthesis of L4 who had the same procedure were stabilized with the Steffee system (Group Steffee-rigid). Thirty-five patients who had the same decompression and bony fusion without instrumentation (Group Noninstrumented) were compared with the former two groups. Clinical results were correlated with the stage of bony fusion. The Steffee system was reliable for stabilizing intervertebral angular instability such as a preoperative intervertebral angle difference of more than 11 degrees in flexion and extension. In the patients who preoperatively had an angle difference of less than 10 degrees, no significant difference was seen between Group Leeds-Keio and Group Steffee. The authors concluded that nonrigid instrumentation can be used to achieve successful bony fusion in patients with degenerative spondylolisthesis, who have a preoperative angle difference less than 10 degrees, with excellent clinical results.     

CAG repeat length in the androgen receptor gene is enhanced in patients with idiopathic azoospermia

Objectives. To determine whether the number of CAG repeats in the androgen receptor gene is enhanced in patients with idiopathic azoospermia.Methods. Using the polymerase chain reaction, the number of CAG repeats was assayed in 41 patients with idiopathic azoospermia and in 48 normozoospermic fertile men.Results. In the control group, the CAG repeat length ranged from 17 to 30 (mean 23.9 ± 2.9); in the azoospermic group, the CAG repeat length ranged from 20 to 34 (mean 26.5 ± 3.5). The difference between the two groups was statistically significant (P = 0.0013). None of the men in the control group had a CAG repeat length greater than 31; four of the azoospermic men had 34 CAG repeats.Conclusions. Results suggest that an increase in the number of CAG repeats in the androgen receptor gene to 31 or greater may be associated with the etiology of at least some cases of idiopathic azoospermia.     

Effects of prolonged cold storage on double peaked vasoconstrictor responses to periarterial nerve stimulation in isolated canine splenic arteries.

1. P2X-Purinoceptors and alpha1-adrenoceptors have previously been shown to involve in the double peaked vasoconstrictor responses to periarterial electrical nerve stimulation in the isolated and perfused canine splenic artery. The present study made an attempt to investigate effects of prolonged cold storage (7 days at 4 degrees C) on vasoconstrictor responses to periarterial electrical nerve stimulation, tyramine, noradrenaline and adenosine 5'-triphosphate (ATP) in the isolated canine splenic artery. 2. The periarterial nerve stimulation (1-10 Hz) readily causes a double peaked vasoconstriction in the non-stored preparations. After cold stored for 7 days, the double peaked vasoconstriction was still recognized, although the response became significantly smaller. The first phase was decreased relatively greater than the second phase by the cold storage. 3. In the cold stored preparations, the dose-response curve for tyramine was shifted to the right in a parallel manner. Prazosin almost completely inhibited tyramine-induced vasoconstriction but alpha,beta-methylene ATP failed to influence the response to tyramine. 4. The vasoconstrictor responses to noradrenaline and ATP were not significantly modified by the prolonged cold storage. 5. From these results, it is concluded that the functions of sympathetic co-transmission of purinergic components might be influenced more than that of adrenergic components in the cold storage canine splenic artery.