Benefits of off-pump bypass on neurologic and clinical morbidity: a prospective randomized trial

BACKGROUND

Neurologic and clinical morbidity after coronary artery bypass grafting (CABG) can be significant. By avoiding cardiopulmonary bypass, off-pump CABG (OPCAB) may reduce morbidity.

METHODS

Sixty patients (30 CABG and 30 OPCAB) were prospectively randomized. Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation. Neurologic testing to detect stroke and (99m)Tc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward. Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli. All examiners were blinded to treatment group. Clinical morbidity and costs were compared.

RESULTS

Coronary artery bypass grafting was associated with more cerebral microemboli (575 +/- 278.5 CABG versus 16.0 +/- 19.5 OPCAB (median +/- semiinterquartile range) and significantly reduced cerebral perfusion after the operation to the bilateral occipital, cerebellar, precunei, thalami, and left temporal lobes (p < or = 0.01). Cerebral perfusion with OPCAB was unchanged. Compared with base line, OPCAB patients performed better on the Rey Auditory Verbal Learning Test (total and recognition scores) at both 2 weeks and at 1 year (p < or = 0.05), whereas CABG performance was statistically unchanged for all cognitive measures. Patients who underwent CABG had more chest tube drainage (1389 +/- 1256 mL CABG versus 789 +/- 586 mL OPCAB, p = 0.02) and required more blood (3.9 +/- 5.8 U CABG versus 1.2 +/- 2.2 U OPCAB, p = 0.02), fresh frozen plasma (3.0 +/- 6.0 U CABG versus 0.5 +/- 2.2 U OPCAB, p = 0.03), and hours of postoperative use of dopamine (16.3 +/- 21.2 hours CABG versus 7.3 +/- 9.7 hours OPCAB, p = 0.04). These differences culminated in higher costs for CABG ($23,053 +/- $5,320 CABG versus $17,780 +/- $4,390 OPCAB, p < 0.0001). One stroke occurred with CABG, compared with none with OPCAB (p = NS). One OPCAB patient died because of a pulmonary embolus (p = NS).

CONCLUSIONS

Compared with CABG, OPCAB may reduce neurologic and clinical morbidity as well as cost.

Improvement in quality of life after bilateral transthoracic endoscopic sympathectomy for palmar hyperhydrosis

OBJECTIVE

To evaluate the efficacy of bilateral transthoracic endoscopic sympathectomy (TES), in alleviating symptoms and improving quality of life for patients in Hawaii.

DESIGN

Retrospective cohort study.

MATERIALS AND METHODS

Patients who had undergone TES were evaluated by phone interview and the SF-36 questionnaire to assess improvements in symptoms and the development of compensatory hyperhydrosis. SF-36 scores were divided into 8 scales and evaluated by one-tailed t-test.

RESULTS

Since 1999, eight patients (five women and three men, mean age 27.4 years old, range 15-41 yrs) underwent TES without significant complication. Length of hospital stay was less than one day for all patients except one, who stayed four days. Estimated operative blood lost was less than 100 ml and no blood transfusions were required. No Horner's syndrome was suffered. After a mean follow-up of 7.0 months (range 1.2-15.8 months), none of the patients had recurrent symptoms in the palms but all reported moderate compensatory hyperhydrosis located mainly in the trunk and lower extremities (two patients). SF-36 scores showed significant improvements in social functioning (p < 0.005), mental health (p < 0.049), and role-physical (p < 0.020) along with an increase in bodily pain (p < 0.012).

CONCLUSION

Although TES resulted in some bodily pain and compensatory hyperhydrosis; these elements were outweighed by the improvement in palmar symptoms, social, mental, and role physical functioning, and overall quality of life.

Pho86p, an endoplasmic reticulum (ER) resident protein in Saccharomyces cerevisiae, is required for ER exit of the high-affinity phosphate transporter Pho84p

In the budding yeast Saccharomyces cerevisiae, PHO84 and PHO86 are among the genes that are most highly induced in response to phosphate starvation. They are essential for growth when phosphate is limiting, and they function in the high-affinity phosphate uptake system. PHO84 encodes a high-affinity phosphate transporter, and mutations in PHO86 cause many of the same phenotypes as mutations in PHO84, including a phosphate uptake defect and constitutive expression of the secreted acid phosphatase, Pho5p. Here, we show that the subcellular localization of Pho84p is regulated in response to extracellular phosphate levels; it is localized to the plasma membrane in low-phosphate medium but quickly endocytosed and transported to the vacuole upon addition of phosphate to the medium. Moreover, Pho84p is localized to the endoplasmic reticulum (ER) and fails to be targeted to the plasma membrane in the absence of Pho86p. Utilizing an in vitro vesicle budding assay, we demonstrate that Pho86p is required for packaging of Pho84p into COPII vesicles. Pho86p is an ER resident protein, which itself is not transported out of the ER. Interestingly, the requirement of Pho86p for ER exit is specific to Pho84p, because other members of the hexose transporter family to which Pho84 belongs are not mislocalized in the absence of Pho86p.

8-Azido-ATP modification of cytochrome c: retardation of its electron-transfer activity to cytochrome c oxidase

Horse heart cytochrome c has been modified by 8-azido-ATP and the electron-transfer activity of the modified cytochrome c's to bovine heart cytochrome c oxidase (CcO) under physiological ionic strengths has been studied by the laser flash photolysis technique with 5-deazariboflavin and EDTA as the electron donor. The intermolecular electron transfer between the redox protein partners was shown to be extremely slow. The 8-azido-ATP-modified system exhibited less than 5% of the intracomplex electron-transfer rate observed between native cytochrome c and CcO under otherwise identical conditions. The binding affinity of the modified cytochrome c was greatly reduced (3 orders of magnitude) at low ionic strengths; however, it was only slightly reduced (by a factor of 2) relative to the native protein at physiological ionic strengths. Thus, the binding affinity of the ATP-cytochrome c adducts is relatively insensitive to the ionic strength compared to the native enzyme, suggesting that a different docking conformation is assumed by the ATP-cytochrome c adducts in their interaction with the oxidase. Since the redox potential of the modified cytochrome c is close to the value of its native form, we conclude that there has been a change in the docking of the cytochrome c to CcO and the electronic coupling between heme c and CuA upon 8-azido-ATP modification.