Axillary artery cannulation for cardiopulmonary bypass reduces cerebral microemboli

BACKGROUND: Aortic cannulation for cardiopulmonary bypass (CPB) is linked to cerebral microemboli emanating from the ascending aorta. Aortic calcification or disease requiring replacement precludes aortic cannulation. Clinical experience with axillary artery cannulation led to the hypothesis that axillary cannulation may be cerebroprotective. METHODS: Five mongrel dogs underwent a median sternotomy and isolation of the right axillary artery. The canine bicarotid brachiocephalic trunk was reconfigured by grafting the origin of the left carotid to the proximal left subclavian artery. Microspheres were injected into the ascending aorta during 4 conditions: before and after reconfiguration, CPB with aortic cannulation, and CPB with axillary cannulation. Brain, kidneys, and skeletal muscle were analyzed for microsphere distribution. RESULTS: Each animal served as its own control for comparison of aortic and axillary cannulation. No significant differences were documented in microsphere deposition for prereconfiguration and postreconfiguration. In the right middle cerebral artery distribution, 2300 +/- 710 microspheres per gram were deposited during aortic cannulation, compared with 540 +/- 110 during axillary cannulation (P <.05). In the left middle cerebral artery region, 2030 +/- 330 microspheres per gram with aortic cannulation were reduced to 1320 +/- 240 with axillary cannulation (P <.05). Axillary cannulation resulted in 73% fewer microspheres in the right brain and 40% fewer microspheres in the left compared with aortic cannulation (P <.05). CONCLUSIONS: Axillary artery cannulation for CPB is cerebroprotective. Altered blood-flow patterns during axillary cannulation may produce retrograde brachiocephalic artery blood flow and competing intracerebral right-to-left collateral blood flow, deflecting emboli from the ascending aorta and arch toward the descending aorta. Expanded use of axillary artery cannulation during cardiac operations could decrease the incidence of stroke.     

Double-blind randomized controlled trial of low-level laser therapy in carpal tunnel syndrome

Several studies have suggested that low-level laser therapy (LLLT) is effective in patients with carpal tunnel syndrome (CTS). In a double-blind randomized controlled trial of LLLT, 15 CTS patients, 34 to 67 years of age, were randomly assigned to either the control group (n = 8) or treatment group (n =7). Both groups were treated three times per week for 5 weeks. Those in the treatment group received 860 nm galium/aluminum/arsenide laser at a dosage of 6 J/cm2 over the carpal tunnel, whereas those in the control group were treated with sham laser. The primary outcome measure was the Levine Carpal Tunnel Syndrome Questionnaire, and the secondary outcome measures were electrophysiological data and the Purdue pegboard test. All patients completed the study without adverse effects. There was a significant symptomatic improvement in both the control (P = 0.034) and treatment (P =0.043) groups. However, there was no significant difference in any of the outcome measures between the two groups. Thus, LLLT is no more effective in the reduction of symptoms of CTS than is sham treatment.     

De novo protein synthesis is required for activation-induced cytidine deaminase-dependent DNA cleavage in immunoglobulin class switch recombination

Activation-induced cytidine deaminase is required for the DNA cleavage step of Ig class switch recombination (CSR). However, its molecular mechanism is controversial. RNA-editing hypothesis postulates that activation-induced cytidine deaminase deaminates cytosine in an unknown mRNA to generate a new mRNA encoding an endonuclease for CSR and thus predicts that DNA cleavage depends on de novo protein synthesis. On the other hand, DNA deamination hypothesis proposes that DNA cleavage is initiated by cytosine deamination in DNA, followed by uracil removal by uracil DNA glycosylase. By using the chromatin immunoprecipitation assay to detect gamma-H2AX focus formation as a marker for DNA cleavage, we found that cycloheximide inhibited DNA cleavage in the Ig heavy-chain locus during CSR. Requirement of protein synthesis in the DNA cleavage step of CSR strengthens the RNA-editing hypothesis.     

Is rhythm control superior to rate control in patients with atrial fibrillation and congestive heart failure?

In 1,009 patients with atrial fibrillation and congestive heart failure, the 2-year mortality rate was 31% in patients treated with rate control (n = 505) versus 29% in patients treated with rhythm control (n = 504). After adjusting for differences in baseline characteristics and medications, no significant difference in mortality was found between the 2 groups.     

The clinical significance of an isofunctioning thyroid nodule

The management of an "isofunctioning" thyroid nodule--defined by radioiodine uptake equivalent to normal thyroid tissue--is often a dilemma. Our goal was to determine the percentage of thyroid nodules that were isofunctioning and the frequency with which carcinoma occurred in an isofunctioning nodule. Patients referred for evaluation of a thyroid nodule from 1990 to 2002 were reviewed and those with an iodine-123 thyroid scintiscan were identified. Nodule size, serum thyrotropin, fine-needle aspiration biopsy, pathology, and follow-up were determined for patients with an isofunctioning, hypofunctioning, or hyperfunctioning thyroid nodule. Of the 562 patients with a thyroid nodule 273 (49%) had a thyroid scan. Nodules were hypofunctioning in 232 (85%), isofunctioning in 29 (11%), and hyperfunctioning in 12 (4%) patients. Mean nodule size and serum thyrotropin level were respectively 2.49 +/- 0.23 cm and 1.73 +/- 0.26 microIU/mL for isofunctioning, 2.47 +/- 0.31 cm and 0.83 +/- 0.21 microIU/mL for hyperfunctioning, and 3.94 +/- 0.13 cm and 1.86 +/- 0.28 pIU/mL for hypofunctioning nodules. Seventeen patients with an isofunctioning nodule underwent thyroidectomy and 12 patients were followed for a mean 27 months without an increase in nodule size. No patient with a hyperfunctioning nodule, six patients (21%) with an isofunctioning nodule, and 44 patients (19%) with a hypofunctioning nodule had a carcinoma. We conclude that the risk of malignancy in an isofunctioning nodule is similar to that of a hypofunctioning nodule and therefore the management should be based on routine fine-needle aspiration biopsy.     

Molecular biology of transitional cell carcinoma

Transitional cell carcinoma (TCC) is the fifth most common solid malignancy in the USA. Radical cystectomy will cure a substantial fraction of patients with minimally invasive TCC, but approximately 50% of patients with muscle-invasive or extravesical disease treated by radical cystectomy alone die of metastatic TCC. Transitional cell carcinoma have a diverse collection of biologic and functional characteristics. This is reflected in a differing clinical course. The limited value of established prognosticators, make the analysis of new molecular parameters of interest in predicting the prognosis of bladder cancer patients; in particular, high-risk patient groups that are at risk of progression and recurrence. Over the past decade, there had been major progress in the elucidation of the molecular genetic changes leading to the development of TCC. This review will highlight these important advances and emphasize the ways in which molecular biology is likely to affect the development of future therapies.     

HIV knowledge among a sample of Puerto Rican and Mexican men and women

This study assessed levels of HIV knowledge and identified factors associated with HIV knowledge among a sample of heterosexual Puerto Rican and Mexican men and women, ages 18 to 45. The sample consisted of 144 men and women living in San Diego County, California, who self-identified as being of Mexican ethnicity and 209 men and women living in Cuyahoga County, Ohio, who self-identified as Puerto Rican. Interviews were conducted by trained, bilingual interviewers. Data were collected on demographic variables, attitudes towards decision-making in relationships, and HIV knowledge and risk behaviors. Puerto Rican individuals were significantly more likely than Mexican individuals to respond correctly to almost one-half of the 12 HIV knowledge items. Multiple logistic regression analysis indicated that higher levels of education, greater U.S. acculturation, legal status and birth in the United States, a self-focused locus of control in relationships, and being male were predictors of higher knowledge.