Laser-assisted anastomosis of large-diameter vessels with the carbon dioxide laser

A low-powered carbon dioxide laser was used to accomplish large-vessel anastomosis in growing minipigs. Results showed excellent patency, near-normal growth rates, and minimal foreign body response.     

Cardiac transplantation and mechanical circulatory assistance: the Texas Heart Institute experience

From January 1984 to September 1988, 245 heart transplants were performed at our institution. During this period, 53 staged cardiac transplant procedures were performed using an intraaortic balloon pump (IABP), an extracorporeal centrifugal blood pump (ECBP), an intracorporal left ventricular assist device, and a total artificial heart. Thirty-four (64%) patients underwent subsequent cardiac transplantation and 28 (53%) were discharged. Our data indicate that patients who suffer rapid onset of heart failure and undergo early circulatory support are suitable candidates for successful staged cardiac transplantation. We have also used mechanical support to treat severe heart failure after transplantation, using IABP and ECBP support, as well as an intraarterial axial flow pump. In immunosuppressed patients, infection is the critical issue affecting outcome. There is a need for development of smaller, simpler, less invasive devices with the capacity to provide both systemic and pulmonary circulatory support.     

Ectopic expression of mucins in colorectal cancer metastasis.

Cancer metastasis is an ectopic growth of malignant cells. In human colorectal cancer, it is hypothesized that, during the progression of the disease to an advanced stage, highly malignant and metastatic tumor cells arise within primary tumors and become predominant. Based on this hypothesis, molecules associated with metastatic cells have been sought by the comparison of surgical specimens from patients at various clinical stages. Colorectal carcinomas with increased metastatic potential and with poor prognosis have been characterized by a loss of an organ-specific mucin determinant (sulfomucin), by an increased expression of non-intestinal sialomucins, and by an ectopic expression of adhesion ligands (sialyl-dimeric Lex antigens) on mucins.     

Total left ventricular outflow tract obstruction due to left ventricular assist device-induced sub-aortic thrombosis in 2 patients with aortic valve bioprosthesis.

This report describes 2 patients with an aortic bioprosthesis. Both patients developed total thrombotic occlusion of the sub-aortic left ventricular outflow tract consequent to insertion of a left ventricular assist device (LVAD). Replacing a mechanical valve with a bioprosthesis in patients receiving a left ventricular assist device offers no additional protection against thrombosis of the aortic prosthesis. Pericardial patching below the aortic prosthesis at the time of LVAD implantation may be performed, but will significantly impede or prohibit the native ventricle from ejecting blood and demonstrating any degree of recovery.     

Development and Validation of a Pig Model for Colon-specific Drug Delivery

The purpose of this investigation was to develop a pig model for colonic drug delivery and to validate the model by determining whether the physiology of the pig colon had been significantly altered after the surgical implantation of a gut cannula into the terminal ileum of the pig. A fistula was created in the terminal ileum of the pig, and a cannula fitted for the purpose of directly administering drug formulations to a point just anterior to the ileocaeco-colonic valve of the gastrointestinal tract. The cephalic vein of the pig was also cannulated to enable continued blood sampling. Sulphasalazine was used as the model drug for the validation study. In the intact colon, sulphasalazine is metabolized by the gut microflora to sulphapyridine which is then absorbed. Sulphasalazine was administered orally to non-fistulated and fistulated pigs and then ileally, via the gut cannula, to fistulated pigs. Absorption of sulphapyridine was monitored by HPLC analysis of plasma samples. There was no significant difference in the absorption obtained for the three groups. Thus it is demonstrated that the colon physiology had not been altered. The colonic pig model is ideal for studying factors affecting the colonic absorption of drugs and as a means for developing drug delivery systems with improved absorption properties.     

Dental Hygienists'' Knowledge and Opinions about Fluorides and Fluoridation.

This article reports results of a study of 563 practicing Minnesota and Wisconsin dental hygienists' knowledge and opinions about fluorides and water fluoridation. Two independent samples were selected randomly from the populations of licensed dental hygienists residing in the two states. Data were collected using a pretested, 42-item, mailed questionnaire. An 84 percent response was achieved with two followup reminders. These data provide baseline information about the caries prevention knowledge and attitudes of practicing dental hygienists in two states. Respondents from both states held similar levels of knowledge about fluorides and opinions about decision making on fluoridation. Fluoride topics, especially water fluoridation, were not receiving high priority in patient education, although nearly all believed that dental hygienists should promote water fluoridation actively. Two-thirds of respondents from both states believed fluoridation decisions should be made by health authorities, rather than by elected officials or through public vote. Greater attention to patient education about fluoride and community water fluoridation is needed by dental hygienists.     

Cochlioquinone A, a nematocidal agent which competes for specific [3H]ivermectin binding sites

Cochlioquinone A, isolated from the fungus Helminthosporium sativum, was found to have nematocidal activity. Cochlioquinone A is a competitive inhibitor of specific [3H]ivermectin binding suggesting that cochlioquinone A and ivermectin interact with the same membrane receptor.     

Studies of Information Processing in Sleep

Two studies of information processing in normal human sleep are reported. In Experiment I it was found that subjects responded differentially in stage 2 sleep to “own name,”“other name,” and tone stimuli (decreasing in that order) as reflected in both the finger plethysmograph (FP)and heart rate (HR) and to some extent the EEG K-complex response, and similarly in REM sleep as reflected in the FP measure and to some extent the HR measure, but not in sleep stage 3–4. In Experiment II it was found that conditioned discrimination acquired during wakefulness persisted in sleep stage 4, as reflected in the FP and HR measures, and sleep stage 2, as reflected in the K-complex response, but not in REM sleep. Results are compared to other studies of information processing in sleep. It is concluded that the results appear to indicate differential availability of the mechanisms of long-term memory, short-term memory, and stimulus preprocessing in the various stages of sleep. The authors further noted a bifurcation of the autonomic nervous system in sleep into two discrete effector limbs: electrodermal and cardiovascular.