Synaptotagmins 1 and 7 in vesicle release from rods of mouse retina.

Synaptotagmins are the primary Ca2+ sensors for synaptic exocytosis. Previous work suggested synaptotagmin-1 (Syt1) mediates evoked vesicle release from cone photoreceptor cells in the vertebrate retina whereas release from rods may involve another sensor in addition to Syt1. We found immunohistochemical evidence for syntaptotagmin-7 (Syt7) in mouse rod terminals and so performed electroretinograms (ERG) and single-cell recordings using mice in which Syt1 and/or Syt7 were conditionally removed from rods and/or cones. Synaptic release was measured in mouse rods by recording presynaptic anion currents activated during glutamate re-uptake and from exocytotic membrane capacitance changes. Deleting Syt1 from rods reduced glutamate release evoked by short depolarizing steps but not long steps whereas deleting Syt7 from rods reduced release evoked by long but not short steps. Deleting both sensors completely abolished depolarization-evoked release from rods. Effects of various intracellular Ca2+ buffers showed that Syt1-mediated release from rods involves vesicles close to ribbon-associated Ca2+ channels whereas Syt7-mediated release evoked by longer steps involves more distant release sites. Spontaneous release from rods was unaffected by eliminating Syt7. While whole animal knockout of Syt7 slightly reduced ERG b-waves and oscillatory potentials, selective elimination of Syt7 from rods had no effect on ERGs. Furthermore, eliminating Syt1 from rods and cones abolished ERG b-waves and additional elimination of Syt7 had no further effect. These results show that while Syt7 contributes to slow non-ribbon release from rods, Syt1 is the principal sensor shaping rod and cone inputs to bipolar cells in response to light flashes.

Validating a risk stratification tool for audit of early outcome after operations for squamous cell carcinoma of the head and neck.

The aim of this study was to validate a case-mix adjustment tool (neural network) for the audit of postoperative outcomes. We tested its calibration and discrimination on two unseen groups of patients being treated for squamous cell carcinoma (SCC) of the head and neck and compared observed complication rates with predicted rates. A total of 196 patients who were treated at two UK NHS institutions between 2016 and 2018 were audited. Preoperative data pertaining to risk (T classification, complexity of operation, and "high-risk" status) were collected, together with data on postoperative complications. Diagnostic test statistics and receiver operating curves (ROC) were used to test the performance of the tool. The score was well calibrated (predicted and observed complication rates both 43%), but discrimination suggested only fair accuracy (ROC 0.66 - 0.68). Adjustment of case mix for the audit of postoperative complications is difficult, although our model suggests that departmental audit is possible, and its accuracy is equivalent to that of other national audits. Further work may elucidate key variables that have not yet been assessed.

Case-mix adjustment in audit of length of hospital stay in patients operated on for cancer of the head and neck.

Patients treated surgically for squamous cell carcinoma (SCC) of the head and neck form a heterogeneous group, and it is difficult to take this variation into account when measuring the quality of care. We have tested the feasibility of mathematical models that allow for the adjustment for case mix when auditing the length of hospital stay as a proxy indicator of the quality of care. We completed a case-note audit of 733 surgical episodes of care for SCC of the head and neck in five cancer networks, and used logistic regression and decision tree analysis to adjust for case mix using pertinent preoperative variables. Risk adjustment models of length of stay included age, alcohol, T classification, performance status, tracheostomy, high-risk status, and complexity of operation. The risk-adjusted length of stay differed significantly between the cancer networks studied (p<0.001). The models performed acceptably for the purpose of audit when this was under 15 days. Length of stay is a measurable outcome that can be used as a benchmark of surgical care. Audits of this after operations for cancer of the head and neck, if reported in national clinical audits, should take case mix into account.

Prevalence of peripheral arterial occlusive disease in patients referred to a tertiary care hospital in Salvador, Bahia, Brazil, for coronary angiography.

The presence of peripheral arterial occlusive disease increases the morbidity and mortality of patients with coronary artery disease. The objective of the present study was to calculate the prevalence of peripheral arterial occlusive disease in patients referred for coronary angiography. This prevalence study was carried out at the Hemodynamics Unit of Hospital Santa Isabel, Salvador, Brazil, from December 2004 to April 2005. After approval by the Ethics Committee of the hospital, 397 patients with angiographic signs of coronary artery disease were enrolled. Diagnosis of peripheral arterial occlusive disease was made using the ankle-brachial blood pressure index (< or =0.90). Statistical analyses were performed using the z test and a level of significance of alpha = 5%, 95%CI, the chi-square test and t-test, and multiple logistic regression analysis. The prevalence of peripheral arterial occlusive disease was 34.3% (95%CI: 29.4-38.9). Mean age was 65.7 +/- 9.4 years for patients with peripheral arterial occlusive disease, and 60.3 +/- 9.8 years for patients without peripheral arterial occlusive disease (P = 0.0000003). The prevalence of peripheral arterial occlusive disease was 1.57 times greater in patients with hypertension (P = 0.007) and 2.91 times greater in patients with coronary stenosis > or =50% (P = 0.002). Illiterate patients and those with little education had a 44% higher chance of presenting peripheral arterial occlusive disease probably as a result of public health prevention policies of limited effectiveness. The prevalence of peripheral arterial occlusive disease in patients referred to a tertiary care hospital in Salvador, Bahia, for coronary angiography, was 34.3%.

Prevalence of peripheral arterial occlusive disease in patients referred to a tertiary care hospital in Salvador, Bahia, Brazil, for coronary angiography

The presence of peripheral arterial occlusive disease increases the morbidity and mortality of patients with coronary artery disease. The objective of the present study was to calculate the prevalence of peripheral arterial occlusive disease in patients referred for coronary angiography. This prevalence study was carried out at the Hemodynamics Unit of Hospital Santa Isabel, Salvador, Brazil, from December 2004 to April 2005. After approval by the Ethics Committee of the hospital, 397 patients with angiographic signs of coronary artery disease were enrolled. Diagnosis of peripheral arterial occlusive disease was made using the ankle-brachial blood pressure index (£0.90). Statistical analyses were performed using the z test and a level of significance of a = 5 percent, 95 percentCI, the chi-square test and t-test, and multiple logistic regression analysis. The prevalence of peripheral arterial occlusive disease was 34.3 percent (95 percentCI: 29.4-38.9). Mean age was 65.7 ± 9.4 years for patients with peripheral arterial occlusive disease, and 60.3 ± 9.8 years for patients without peripheral arterial occlusive disease (P = 0.0000003). The prevalence of peripheral arterial occlusive disease was 1.57 times greater in patients with hypertension (P = 0.007) and 2.91 times greater in patients with coronary stenosis ³50 percent (P = 0.002). Illiterate patients and those with little education had a 44 percent higher chance of presenting peripheral arterial occlusive disease probably as a result of public health prevention policies of limited effectiveness. The prevalence of peripheral arterial occlusive disease in patients referred to a tertiary care hospital in Salvador, Bahia, for coronary angiography, was 34.3 percent.

Endovascular treatment of middle cerebral artery aneurysms as first option: a single center experience of 92 aneurysms.

BACKGROUND AND PURPOSE: We conducted a retrospective evaluation of the results of endovascular treatment (EVT) of middle cerebral artery aneurysms (MCAAs) in a center where embolization is the first treatment option considered. MATERIALS AND METHODS: Ninety-two MCAAs were diagnosed in 87 patients between September 2001 and January 2006. The strategy of treatment (endovascular versus surgical), the clinical and angiographic results of embolization, and the ensuing complications are described. RESULTS: Initially, 59 aneurysms (64.1%) in 55 patients were embolized, 18 (19.6%) were clipped, and 15 (16.3%) were not treated. Four endovascular procedures failed (7.3%), and 55 aneurysms in 51 patients were finally treated by embolization. During the procedure, complications occurred in 13 patients (25.5%) comprising 3 ruptures and 10 thromboembolisms. In the follow-up, 4 patients having a preoperative complication had a modified Rankin scale more than 2 (3 patients [5.9%]) or died (1 patient [2.0%]). Of the 55 embolized aneurysms, according to the Raymond scale, 23 (41.8%) were completely occluded, 24 (43.6%) retained a residual neck, and 8 (14.6%) were residual at the end of the first procedure. No bleeding was detected during the follow-up period in the embolized patients. CONCLUSION: EVT of MCAA is effective for preventing rebleeding episodes within the first year of treatment judging by historical controls. The real question is whether clipping or coiling of MCAAs is better in terms of reducing rebleeding rates and complications rates in the long term, and such a determination would require a far larger number of patients over a much longer observation period.

Preoperative embolization of a cervicodorsal paraganglioma by direct percutaneous injection of onyx and endovascular delivery of particles.

We report the feasibility and efficacy of percutaneous injection of Onyx (Micro Therapeutics, Irvine, Calif.), a nonadhesive liquid embolic agent, into an unusually located paraganglioma, followed by endovascular embolization with particles before surgery.

Mammomonogamus laryngeus (Railliet, 1899) infection in buffaloes in Rio Grande do Sul, Brazil.

Parasites of the genus Mammomonogamus affect the respiratory tract of domestic animals. The present study was carried out to determine the presence of Mammomonogamus laryngeus infection and to analyze its lesions in infected buffaloes in Rio Grande do Sul, Brazil, between April and November 1999. The infection rate was 30.5%. In 32 infected buffaloes, the worm pairs collected per animal did not exceed 20. The microscopic diagnosis showed intense polypoid to intramucosal proliferation at the entrance to the pharynx, to which the parasites had adhered, with foci of multifocal hydropic degeneration of the epithelium or individual degeneration of epithelial cells with mild intraepithelial inflammatory infiltrate. The submucosa revealed intense lymphocyte infiltrate extending into the salivary glands. The submucosa also showed formation of structures that resemble lymphoid follicles.