Efficacy of low-dose dopamine infusion

Urine output following administration of a low-dose dopamine infusion was assessed in 20 very immature infants (median gestational age 27 weeks). Prior to the infusion, all infants had had a period of anuria. Urine output improved significantly during the second 24 h after commencing the infusion but, at that time period, urine output was greater than 2 ml/kg/h (designated a good response) in only 13 infants. There was no significant difference in gestational age, birth weight, period of anuria or fluid input of infants who had a good or a poor response to dopamine. Although the baseline blood pressure did not differ significantly between these two groups, the increase in blood pressure resulting from dopamine administration was significantly greater in those infants with a good response in urine output (p<0.02). We conclude that low-dose dopamine infusion can improve urine output in very immature infants. Our results suggest that there may be inter-individual variation in the sensitivity to dopamine.     

Three-phase radionuclide scintigraphy of the hand

Three-phase radionuclide scintigraphy of the hand was performed on 116 patients. Normal and abnormal patterns for radionuclide angiography, immediate post-injection blood-pool images, and delayed scans (3-4 hr.) were established. Of 80 patients with normal circulation, 61 (76%) had equal radial and ulnar artery flow bilaterally, while in 19 (24%) either the radial or ulnar artery was dominant. Abnormal studies were grouped into three categories: suspected vascular lesions (Group I), pain of uncertain etiology (Group II), and patients evaluated before and after reconstructive surgery (Group III). The diagnosis was correct in 89% of the patients in Group I (34/38), 89% of those in Group II (57/64), and all of those in Group III (14/14). Three-phase scintigraphy of the hand yields significant information about perfusion and bone metabolism.     

Restoration of thrombolytic potential in plasminogen-deficient mice by bolus administration of plasminogen

Homozygous plasminogen-deficient (Plg-/-) mice had a significantly reduced thrombolytic capacity toward intravenously injected 125I-fibrin labeled plasma clots prepared from Plg-/- murine plasma (9% +/- 3% lysis after 8 hours; (mean +/- SEM, n = 6), as compared with 82% +/- 8% in wild-type mice; P < .0001). Bolus injection of 1 mg purified murine plasminogen in 10- to 17-week-old Plg-/- mice increased the plasminogen antigen and activity levels at 8 hours to normal levels (130 +/- 5 micrograms/mL). Plasminogen administration was associated with significant restoration of thrombolytic potential (64% +/- 7% spontaneous clot lysis; P < .0001 versus lysis without plasminogen injection). Bolus injection of 1 mg plasminogen in homozygous tissue- type plasminogen activator-deficient (t-PA-/-) mice doubled the plasminogen antigen and activity levels after 8 hours and increased 125I-fibrin clot lysis at 8 hours from 13% +/- 3% to 34% +/- 5% (P = .008). Fibrinogen, t-PA antigen and alpha 2-antiplasmin activity levels after 8 hours were not significantly different in the groups with or without plasminogen injection. Injection of plasminogen induced a variable increase (on average 7- to 10-fold) of PAI-1, but no correlation with the extent of spontaneous clot lysis was observed. Histopathologic examination at the end of the experiments revealed that fibrin deposition in the liver of Plg-/- mice was slightly reduced 8 hours after bolus plasminogen injection (P = .007) and markedly reduced after 24 hours (P < .0001). Plasminogen antigen levels in liver extracts were comparable with those found in wild-type mice at 8 hours (130 +/- 20 versus 110 +/- 15 ng/mg protein) and decreased to 25 +/- 3.2 ng/mg protein at 24 hours. Thus, restoration of normal plasminogen levels in Plg-/- mice normalized the thrombolytic potential toward experimentally induced pulmonary emboli, and resulted in removal of endogenous fibrin deposits within 24 hours.     

Design,synthesis, in silico ADMET profile and GABA‐A docking of novel phthalazines as potent anticonvulsants

A new series of 2‐substituted‐2,3‐dihydrophthalazine‐1,4‐diones ( 2 ? 9 ) were designed and synthesized to evaluate their anticonvulsant activity. The neurotoxicity was assessed using the rotarod test. Molecular docking was performed for the synthesized compounds to assess their binding affinities as γ‐aminobutyric acid A (GABA‐A) receptor agonists as a possible mechanism of their anticonvulsant action, to rationalize their anticonvulsant activity in a qualitative way. The data obtained from the molecular modeling was strongly matched with that obtained from the biological screening, which revealed that compounds 5 _a , 9 _b , and 9 _h showed the highest binding affinities toward the GABA‐A receptor and also showed the highest anticonvulsant activities with relative potencies of 1.66, 1.63, and 1.61, respectively, compared with diazepam. The most active compounds 5 _a , 9 _b , and 9 _h were further tested against maximal electroshock seizures. Compounds 5 _a and 9 _b showed 100% protection at a dose level of 125 µg/kg, while compound 9 _h exhibited 83.33% protection at the same dose level. A GABA enzymatic assay was performed for these highly active compounds to confirm the obtained results and to explain the possible mechanism for their anticonvulsant action. These agents exerted low neurotoxicity and a high safety margin compared with valproate as a reference drug. Most of our designed compounds exhibited a good ADMET profile.     

Non-invasive diagnosis of Crohn’s disease: All that glitters is not gold

Crohn’s disease (CD) is associated with occurrence of inflammation in the digestive tract. Diagnosing intestinal bowel diseases can be difficult because bowel disease can be tricky as it does not have unique symptoms. Endoscopy and histopathological tests play a crucial role in the diagnosis and management of inflammatory bowel diseases. Various techniques can be used to diagnose CD. Nevertheless, the diagnosis of CD mostly requires having patients in the hospital. During the SARS-CoV-2 pandemic, that might not be very feasible, as minimizing contact is essential, but can an alternative diagnosis technique be enough to provide a definitive diagnosis?     

Microstructure and Mechanical Properties of Friction Stir Welded 2205 Duplex Stainless Steel Butt Joints

Friction stir welding (FSW) as a solid-state process is an excellent candidate for high softening temperature materials welding; however, extending the tool life is required to make the process cost-effective. This work investigates the use of a high pin to shoulder ratio (65%) tungsten carbide (WC) tool for friction stir welding of 5 mm thick 2205 DSS to extend the tool life of this low-cost tool material. In addition, the effect of FSW parameters in terms of rotational rates, travel speeds, and downward forces on the microstructural features and mechanical properties of the welded joints were investigated. Characterization in terms of visual inspection, macro and microstructures, hardness, and tensile testing was conducted. The obtained results indicated that the combined rotational rate, travel speed, and downward force parameters govern the production of defect-free joints. The 2205 DSS friction stir welds show an enhancement in hardness compared to the base material. The stir zone showed a significantly refined grain structure of ferrite and austenite with the reduction in the average grain size from 8.8 µm and 13.3 µm for the base material to 2.71 µm and 2.24 µm, respectively. Moreover, this joint showed higher yield strength and ultimate tensile strength compared to the DSS as-received material.