Colonic Perforation Following Intraoperative Temporary Pacemaker Implantation

OZA, P.M., et al .: Colonic Perforation Following Intraoperative Temporary Pacemaker Implantation. This report describes the case of a 73-year-old man who was referred for consultation for increasing abdominal free air 1 week after he underwent surgery for aortic valve replacement and coronary artery bypass grafting with intraoperative pacemaker implantation. Laparoscopic exploration revealed that the pacemaker wires had passed through the left transverse colon. Although no previous reports of colonic perforation due to pacemaker lead placement was found, this experience suggests that physicians should suspect this complication in patients with increasing free intraabdominal air and peritoneal signs who have recently undergone placement of a temporary cardiac pacing system. (PACE 2003; 26[Pt. I]:918–919)     

General Practitioners' Changes to Practice due to Aggression at Work

The objective of this study was to record changes made by awide body of general practices due to experience of, or concernsover, aggression. The study involved a retrospective surveyof all general practitioners (GPs) in the West Midlands HealthAuthority region using a piloted postal questionnaire. A totalof 1093 (40.6%) doctors responded out of a potential 2694. Seven-hundredand ninety-four (72.7%) of doctors had not made changes dueto fears over aggression. The other 299 doctors listed 68 differenttypes of change to practice (premises, process) or to motivationbecause of fears of abuse. These changes included striking offmore patients, recorded by 128(11.7%); discussing the problemat practice meetings, by 122 (11.2%); installing panic buttons,by 94(8.6%) and increasing the use of deputizing service, by76 (7%). Seventy-three (6.7%) doctors felt less committed tomedicine and 40 (3.7%) felt less confident as doctors, feelingsthat were significantly more likely to be volunteered by womenand Asian trained practitioners. Unfortunately, most of thechanges, such as putting up security screens or prescribingon demand, were potentially likely to be counterproductive.This study therefore illustrates the need for more support andadvice to practices on how to avoid and respond to aggressionat work.     

The effect of caput succedaneum on oxygen saturation measurements

Summary. Advances in oximetry have allowed the obstetrician to measure oxygen saturation in the fetus with non-invasive transcutaneous techniques. The influence of caput succedaneum formation on the oxygen saturation results obtained with a pulse oximeter was studied in 30 newborn infants. Caput was associated with a reduced oxygen saturation reading (mean reduction of 15%; P <0^.001). This effect is partly due to a true drop in local tissue oxygenation but is exacerbated by a systematic error intrinsic to the physics of spectrophotometry. If continuous intrapartum oximetry is ever to become a part of routine obstetric monitoring then probes that pass through the cervix beyond the caput of the presenting part will be required if erroneously low readings are to be avoided.     

Epitopic characterization of the human wild-type and mutant ras proteins using membrane-bound peptides

Overlapping octapeptides encompassing the entire sequences of the human oncogene products Ha-ras, K-ras and N-ras protein were synthesized as spots on polypropylene membrane sheets. The binding of anti-row protein monoclonal antibodies (mAbs) to the membrane-bound peptides was assessed using an enzyme-linked immunosorbent assay. Epitopes of 10 of 18 mAbs to the human ras proteins were mapped and identified by this procedure. The epitopes of nine of the mAbs are within residues 28-39 in the constant domain common to the three ras proteins, whereas the epitope of the tenth (mAb 21) spans residues 136-144 in Ha-ras. The minimal lengths of epitopes of all ten of the mAbs were further precisely mapped using peptides of varying length, and the tolerance for mAb binding of mutated epitopes was determined by systematically replacing each residue in the epitope with each of the 20 common amino acids. The results show that most of these mAbs have essentially the same binding specificity, namely for the sequence YDPT (residues 32–35) or for slightly longer sequences containing these residues. This site is in the switch 1 region (residues 32-38) in the ras effector loop, indicating that some of the same residues important for the interaction of ras with other proteins (GTPase-activating protein, neurofibromin or raf) are highly antigenic. In addition, we investigated epitopes and specificity of five mAbs against the activated human ras proteins by the same procedure. The information gained from this study should be useful both for study of the complicated functions of ras proteins and for clinical detection of ras oncogenes in human tumor cells.     

Expression of acquired immunity to the hookworm Ancylostoma ceylanicum in hamsters

Four experiments are described in which hamsters, initially exposed to primary infection with Ancylostoma ceylanicum , were given a homologous challenge and components of the secondary response were quantified and compared to relevant control groups. The initial establishment of the L3 larvae was not prevented in immunized hamsters but their growth was slowed and virtually all larvae were lost within a week of challenge, when the majority were still at the L4 stage of development. The loss of worms was associated with an accelerated mucosal mastocytosis and increased systemic antibody. Thus acquired immunity to hookworm larvae in this system acted on L3 and L4 stages, thereby preventing larvae from maturing in immunized animals. In contrast to primary infections, immunized hamsters responding to a challenge infection did not lose weight nor did they experience significant anaemia, because of the lack of adult worms. The secondary immune responses therefore prevented manifestation of hookworm disease among immunized-challenged animals .     

Relationship between hepatic blood flow,liver tests,haemodynamic values and clinical characteristics in patients with chronic liver disease*

Although hepatic blood flow (HBF) has been measured in patients with liver disease for many years, the results of these studies have not provided clear information concerning the usefulness of this measurement. Hepatic blood flow was measured in 392 patients with either cirrhosis (n= 356) or hepatic fibrosis (n= 36). The control group included 59 subjects with normal liver architecture. Hepatic clearance of indocyanine green (ICG) was markedly reduced in patients with cirrhosis and hepatic fibrosis compared with controls (182±5, 276±22 and 421±25 mL/min, respectively). In patients with cirrhosis, ICG clearance and extraction were significantly correlated, but were not correlated to HBF. Although HBF did not differ between patients with cirrhosis and controls (1.26±0.04 vs 1.35±0.07 L/min, respectively), patients with hepatic fibrosis had lower HBF (1.04±0.07 L/min; P< 0.05). In patients with cirrhosis, no correlation was observed between HBF and cardiac output, mean arterial pressure, azygos blood flow, the hepatic venous pressure gradient or Pugh's score. However, a significant difference in HBF was observed in patients with and without hepatic encephalopathy (1.00±0.09 vs 1.28±0.03 L/min, respectively; P<0.05). In conclusion, the present study shows that, in patients with cirrhosis, HBF is normal and is not related to other haemodynamic values or liver tests. These results discourage the measurement of HBF in the evaluation of patients with cirrhosis.     

Analysis of the Effectiveness of In-Office and Transtelephonic Follow-Up in Terms of Pacemaker System Complications

A study was undertaken to determine the most effective method of pacemaker follow-up in terms of the total number of complications detected and yield per follow-up in single and dual chamber pacing systems. The analysis involved 9,786 patient records from 635 patients. The records were reviewed with respect to method of follow-up, number of chambers paced, and complications detected. Complications included: oversensing, undersensing, noncapture, pocket and diaphragmatic stimulation, pacemaker mediated tachycardia, crosstalk, pulse generator malfunction, lead malfunction, infection/erosion, premature end of service, exit block, and other miscellaneous problems. Eight thousand two hundred eighty-eight of the 9,786 follow-ups were performed in the office while 1,498 were transtelephonic. Single chamber pacing systems were implanted in 329 patients and 306 were dual chamber systems. A total of 599 complications were detected. Analysis yielded a per patient complication rate of 5.1 % (single chamber) and 8.4% (dual chamber) for in-office follow-up. This compared to a transtelephonic follow-up per patient complication rate of only 0.3% (single chamber) and 1.0% (dual chamber). In-office pacemaker follow-up is significantly more effective (P < 0.001) than transtelephonic follow-up in detecting both single and dual chamber pacemaker system complications.