Differential expression of the lenticular antioxidant system in laboratory animals: a determinant of species predilection to oxidative stress-induced ocular toxicity?

PURPOSE: Various animal species have been used to study oxidative stress-induced cataractogenesis; however, given that differences in the expression of the lens antioxidant system may influence species susceptibility to oxidative stress, we compared and contrasted a broad spectrum of components of the lens antioxidant system in dog, rat, marmoset, and rabbit. METHODS: Lenses collected from beagle dogs, Sprague-Dawley rats, marmosets, and New Zealand white rabbits were assayed for reduced glutathione (GSH), and activities of copper-zinc and manganese superoxide dismutase (CuZn-SOD; Mn-SOD), catalase (CAT), glutathione peroxidase (GPX), gamma-Glutamylcysteine synthetase (GCS), glutathione reductase (GR), glutathione-S-transferases (GST), and glucose-6-phosphate dehydrogenase (GPDH), and Trolox equivalent antioxidant capacity (TEAC). RESULTS: Expression of the lens antioxidant system varied considerably between species. Marmoset lens contained the highest levels of GSH, its respective biosynthetic and recycling enzymes GCS and GR, and the associated H(2 )O(2)-dismutation enzyme GPX. Activities of both SOD isoforms were also highest in marmoset lens. However, activities of the xenobiotic-conjugating enzyme GST and NADPH-generating enzyme GPDH were relatively low. In contrast, dog lens had the lowest levels of GSH, GCS, GR, and Cu-Zn SOD (1/2, 1/2 and 1/33, and 1/63 that in marmoset) but highest levels of GST and GPDH. Rabbit lens contained the highest CAT activity, at up to 3.5-fold that for marmoset and rat. CONCLUSION: These results demonstrate substantial variation in lens antioxidant systems between different laboratory animal species. Given that such variation may affect relative susceptibility to oxidative stress-mediated ocular toxicity, our findings may provide useful information when choosing different animal species for lens research.     

Large-volume preparation of pyridoxylated hemoglobin with high P50

A technique is described for the preparation of a stroma-free pyridoxylated hemoglobin solution in volumes of up to 20 liters and hemoglobin concentrations of 18–20 g%. The methemoglobin concentration is 3–7%; the phospholipid content is 5–10% of lysate; and normal values for prothrombin time and activated partial thromboplastin time are obtained. Electrophoresis on cellulose acetate strips shows that 70% of the hemoglobin is covalently linked to pyridoxal-5′-phosphate. This proportion can be raised to greater than 85% (PLP fraction) by batch purification with DEAE-Sephadex. The final solution has an in vitroP₅₀ of 22–26 mm Hg (pH = 7.40, pCO₂ = 40 mm Hg, temperature = 37°C). Both the proportion of pyridoxylated to unmodified hemoglobin and the P₅₀ remain unchanged throughout the course of total exchange transfusion in the baboon.     

Preferences for gender of family physician among Canadian European-descent and South-Asian immigrant women

OBJECTIVE: The aim of this study was to investigate expressed preferences for family physician (FP) gender among Canadian European-descent (CED) and Canadian South-Asian (CSA) immigrant women. METHOD: An 'on-site' survey was conducted in community-based institutions in Toronto in order to determine preferences for the gender of FP under various health care scenarios: overall health care; gender-sensitive examinations; emotional problems; general ailments; and life-threatening conditions. RESULTS: Ninety-four women responded to this survey (CED = 50, CSA = 44), response rate 77.3%. For all health care scenarios, CED and CSA women similarly expressed either a preference for a female FP or no preference. More than two-thirds of women preferred a female FP for gynaecological examinations (CED, 72.9%; CSA, 83.7%) or examinations with private body part exposure (CED, 72%; CSA, 81.8%). For 'emotional problems', half of the women preferred a female FP and the other half had no preference. A similar pattern was observed for 'overall health care', with some shift to female physician preference among CSA women (60.5%) compared with CED women (53.2%). For the 'overall health care' scenario, CED and CSA women who preferred a female FP had a higher frequency of seeing female physicians within the last 5 years (CED, P < or = 0.01; CSA, P < or = 0.05), and attributed 'positive' social skills more to female physicians (CED, P < or = 0.01; CSA, P < or = 0.01) compared with women with no preference for the gender of the FP. Yet, CED women with a female FP preference were more likely to have a concurrent female FP (P < or = 0.01), and to rate past experiences with female physicians as high (P < or = 0.01) and with male physicians as low (P < or = 0.05) compared with CED women with no preference. In the CSA group, women with a preference for a female FP were more likely to be unemployed (P < or = 0.01) and have low social support (P < or = 0.01). CONCLUSIONS: Despite similar physician gender preference patterns, factors associated with these preferences show some differences between CED and CSA women.     

Effect of clear aligner wear protocol on the efficacy of tooth movement:: A randomized clinical trial

ObjectivesTo compare the efficacy of orthodontic tooth movement with three aligner wear protocols: 7 day, 10 day, and 14 day.Materials and MethodsEighty patients were randomly allocated into three groups: group A (7-day changes), group B (10-day changes), and group C (14-day changes). The posttreatment scans were compared with the final virtual treatment simulations through digital superimposition. The differences between predicted and actual achieved treatment outcomes were computed in six angular and six linear dimensions. Differences >0.5 mm for linear measurements and >2° for angular measurements were considered clinically relevant.ResultsWithin groups, and irrespective of wear protocol, all linear discrepancies in both jaws were deemed clinically insignificant (<0.5 mm) while nearly all angular discrepancies were considered clinically significant (>2.0°). When the three groups were compared, group C (14-day changes) showed significantly greater accuracy in the posterior segment for maxillary intrusion, distal-crown tip and buccal-crown torque, and mandibular intrusion and extrusion. The mean treatment duration in the 7-day aligner change group was nearly half that of the 14-day aligner change group (5 months vs 9 months).ConclusionsFourteen-day changes were statistically significantly more accurate in some posterior movements. However, this difference in accuracy did not exceed the threshold for clinical significance (>0.5 mm/>2.0°). Achieving a clinically similar accuracy between the 7-day protocol and 14-day protocol in half the treatment time suggests a 7-day protocol as an acceptable treatment protocol. Clinicians may consider slowing down to a 14-day protocol if challenging posterior movements are desired.     

Uterus didelphys with obstructed right hemivagina, ipsilateral renal agenesis and right pyocolpos: a case report

Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis (OHVIRA Syndrome) is a rare congenital anomaly of the female genital tract. Uterus didelphys occurs when the midline fusion of the mullerian ducts is arrested, either completely or incompletely. Women with didelphic uterus may be asymptomatic and unaware of having a double uterus. They may present with complaints of dysmenorrhoea and dyspareunia. A 25 year old woman attending the infertility clinic at Nizwa regional referral hospital presented with history of dysmenorrhoea and foul vaginal discharge with right cystic pelvic mass. She was diagnosed as a case of double uterus with obstructed right hemivagina and right pyocolpos with ipsilateral renal agenesis after routine ultrasonography in the clinic followed by MRI. Excision of the right vaginal septum with drainage of 200 ml of purulent discharge was performed. She was relieved of her symptoms and conceived promptly after the surgical excision of the partial vaginal septum.     

Demographic and Videostroboscopic Assessment of Vocal Pathologies

Successful treatment of bilateral vocal fold lesions depends on the accuracy of the diagnosis. The application of stroboscopy to the study of vocal fold vibration has led to dramatic advances in the understanding of vocal fold physiology. Laryngeal stroboscopy is the state of the art diagnostic tool and this technique provides valuable information about the nature of the vibration and a visual image that can be used both for immediate analysis and as a permanent record for comparison of repeated examination at a later date. In this study we are presenting demographic analysis and videostroboscopic assessment in 112 cases of different vocal pathologies. Stroboscopic parameters like glottic closure, amplitude, vocal fold edge, symmetry, periodicity and mucosal wave pattern were studied and statistically significant relationship with different vocal pathologies were obtained.