A neuromuscular monitoring system based on a personal computer

We have developed a computerized neuromuscular monitoring system (NMMS) using commercially available subsystems, i.e., computer equipment, clinical nerve stimulator, force transducer, and strip-chart recorder. This NMMS was developed for acquisition and analysis of data for research and teaching purposes. Computer analysis of the muscle response to stimulation allows graphic and numeric presentation of the twitch response and calculated ratios. Since the system can store and recall data, research data can be accessed for analysis and graphic presentation. An IBM PC/AT computer is used as the central controller and data processor. The computer controls timing of the nerve stimulator output, initiates data acquisition, and adjusts the paper speed of the strip chart recorder. The data processing functions include establishing control response values (when no neuromuscular blockade is present), displaying force versus time and calculated data graphically and numerically, and storing these data for further analysis. The general purpose nature of the computer and strip chart recording equipment allow modification of the system primarily by changes in software. For example, new patterns of nerve stimulation, such as the posttetanic count, can be programmed into the computer system along with appropriate data display and analysis routines. The NMMS has functioned well in the operating room environment. We have had no episodes of electrocautery interference with the computer functions. The automated features have enhanced the utility of the NMMS. The prime advantages of this system are (1) the ability to customize its features by altering its controlling programs, (2) the ready availability of the hardware and software, (3) the general purpose nature of the system, so that it is not limited to this one application, and (4) the adaptable nature of the system.     

Novel antagonists of the 5-HT3 receptor. Synthesis and structure-activity relationships of (2-alkoxybenzoyl)ureas.

A series of benzoylureas derived from bicycle amines were prepared and evaluated for 5-HT3 antagonist activity on the rat isolated vagus nerve. From among these compounds, those analogues which were ortho substituted by an alkoxy group on the benzoyl function were shown to be potent 5-HT3 antagonists with similar or greater potency than the standard agent ondansetron. NMR and X-ray crystallography studies showed these o-alkoxy compounds to exist as a planar, hydrogen-bonded, tricyclic ring system. In molecular modeling studies on endo-N-[[(8-methyl-8-azabicyclo[3.2.1]octan-3-yl-amino] carbonyl]-2-(cyclopropylmethoxy)benzamide (30) the central hydrogen-bonded ring was able to mimic an aromatic ring present in previously reported 5-HT3 antagonists.     

Correlation between the intensity of cytomegalovirus infection and the amount of perivasculitis in aortic allografts

Abstract  We previously demonstrated that cytomegalovirus (CMV) infection enhanced perivascular inflammation in rat aortic allografts. In this study, we investigated the relationship between the CMV infection load and the magnitude of perivasculitis (chronic rejection) in aortic transplants. Rats received or-thotopic abdominal aortic grafts, different degrees of total body irradiation (TBI) for immunosuppres-sion and CMV inoculation. The spleens of the rats receiving 5 Gy of TBI contained more infectious virus and viral antigens than those of rats receiving 3 Gy of TBI or no TBI. Although the number of inflammatory cells infiltrating the perivascular area was decreased after TBI, CMV infection resulted in increased perivasculitis in rats that received 5 Gy of TBI as compared to non-infected animals. This virus-induced effect was characterized predominantly by an increased T-cell infiltration, including CD4 and CD8 T-cells. It is concluded that an enhanced systemic CMV infection during severe immunosuppressive therapy can accelerate the development of chronic rejection, which seems to be mediated mainly by T-cells.     

Treatment of stress response during balanced anesthesia. Comparative effects of isoflurane, alfentanil, and trimethaphan.

Acute hypertensive responses during nitrous oxide-opioid-relaxant anesthesia are a common clinical problem. In adult men undergoing radical prostatectomy procedures and anesthetized with a standardized technique, we evaluated the effectiveness of alfentanil, isoflurane, and trimethaphan in treating acute hemodynamic and stress hormone responses to surgical stimulation. Stress hormone concentrations were measured 1 min before skin incision, after the onset of an acute hypertensive response, and after returning the mean arterial pressure to within 10% of the preincision values with one of the three treatment modalities. Pretreatment plasma alfentanil concentrations (151 +/- 47 to 156 +/- 47 ng.ml-1) and end-tidal nitrous oxide concentrations (66 +/- 2 to 68 +/- 2%) were similar in all three groups. Acute hypertensive events were associated with significantly increased concentrations of catecholamines and vasopressin (antidiuretic hormone [ADH]). Whereas intravenous alfentanil returned all hormone concentrations to preincision values, norepinephrine and glucose concentrations were significantly increased after adjunctive isoflurane administration. Although trimethaphan decreased the norepinephrine concentration, the epinephrine, beta-endorphin, cortisol, ADH, and glucose concentrations were significantly increased compared to preincision values. However, the persistent elevation in the posttreatment ADH concentration in the trimethaphan group was the only significant difference between the three groups. Mean (+/- standard deviation) times to awakening (2.8 +/- 3.3 to 3.8 +/- 4.2 min), extubation (8.1 +/- 4.8 to 10.3 +/- 8.5 min), and orientation (19.6 +/- 20.4 to 24.6 +/- 19.1 min) were similar in all three groups. Naloxone was required more frequently in patients in the alfentanil (35%) and isoflurane (24%) groups than in the trimethaphan group (4%).(ABSTRACT TRUNCATED AT 250 WORDS)