Die Verwendung eines Nervenstimulators zur sicheren Platzierung von Ilisarov-Drähten

OBJECTIVE: Avoidance of potential iatrogenic nerve injury during insertion of Ilizarov fine wires into areas of high anatomic risk by using a modified nerve stimulation technique. INDICATIONS: Application of the Ilizarov ring fixator to areas of high anatomic hazard, in situations where anatomic topography may be distorted by previous surgery, trauma, or congenital anomalies. CONTRAINDICATIONS: Use of systemic muscle relaxants. Caution in patient with cardiac pacemaker. SURGICAL TECHNIQUE: Preliminary experiments showed that a standard nerve-stimulating device can deliver a negatively charged, monophasic square pulse of current through Ilizarov wires. During the application of an Ilizarov frame to potentially hazardous anatomic regions, providing no systemic muscle relaxants are used, a voltage field sufficient to cause nerves in close proximity to the Ilizarov wire to depolarize is produced. Identification of a distal muscle twitch provoked by the stimulation may indicate a potential for iatrogenic nerve injury. RESULTS: Results show that with the nerve stimulator set at 2.5 mA (pulsed at a frequency of 2 Hz), peripheral nerves are stimulated if they lie within 5 mm of the wires. Should a distal muscle twitch occur, wires should be repositioned so that equivalent stimulation produces no twitch. The technique was used during Ilizarov frame application in ten patients, with only a single occurrence of distal muscle twitches in a lower-leg frame. Following repositioning of the Ilizarov wire in this case, no further twitches were observed, indicating that no Ilizarov wire was inserted close to peripheral nerves. No neurologic impairment was present postoperatively.     

Bilateral arthrography of the wrist

In order to determine the true significance of a positive arthrogram in the investigation of wrist pain, a prospective trial was carried out in 60 patients, using the opposite asymptomatic wrist as a control. Of the 46 patients with positive findings in the symptomatic wrist, 34 (74%), had positive arthrograms in the opposite, asymptomatic, wrist. As a result of this, we conclude that a unilateral arthrogram is of little diagnostic value and we recommend the use of the opposite, asymptomatic, wrist as a control.     

An in vivo investigation into bond failure rates with a new self-etching primer system.

Self-etching primers have recently been introduced to simplify the orthodontic bonding process. The aim of this study was to compare the effectiveness of such a product with conventional 2-stage etching and priming with 37% o-phosphoric acid and a conventional unfilled primer. Twenty consecutive patients having orthodontic bonds placed were selected to participate in this cross-mouth control study. Diagonally opposite quadrants were randomly allocated to either the self-etching primer group or the conventional etching and priming group. A total of 364 teeth were bonded with a light-cured diacrylate adhesive; bond failures were then monitored over 6 months. There were 20 bond failures (10.99%) in the self-etching primer group and 9 bond failures (4.95%) in the conventional etch and priming group over this period. The results were analyzed with the McNemar test and 95% confidence interval. The difference between the failure proportions was -0.06 with an associated 95% confidence interval of -0.121 to 0.001. This study produced weak evidence to suggest that bond failures with a self-etching primer will be higher than those with conventional etching and priming. This increased likelihood of bond failure must be weighed against the time advantage of the self-etching primer when used at the initial bonding appointment.     

INGUINAL HERNIA REPAIR BY LAPAROSCOPIC SURGEONS: EARLY EXPERIENCE AND ATTITUDES

The introduction of laparoscopic inguinal hernia repair (LIHR) has been controversial. A questionnaire was sent to all general surgeons in New Zealand to document the early experience with LIHR and attitudes towards it. Of the 118 replies (response rate 55%). 74 were from laparoscopic surgeons. 26 of whom had performed 564 (201 public. 363 private) LIHR (23 bilateral) until January 1994. Only nine (35%) of these surgeons had assisted an experienced surgeon before performing an LIHR. and only four (15%) were supervised by an experienced surgeon during their first case. The transabdominal preperitoneal technique of LIHR was used by 14 (54%) surgeons. the extraperitoneal technique by eight (31%), and the tronsabdominal onlny technique by four (15%). There were 29 (5%) recurrences, 17 (3%) neuropathies. seven (1.2%) conversions, four (0.7%) miijor perforations. and one (0.17%) death. Of the 26 surgeons who performed LIHR, 20 (77%) were concerned about the absence of long-term results. 14 (54%) considered that the optimal technique had not been established. 13 (50%) were concerned about the unique complications associated with LIHR. 11 (42%) were less enthusiastic about performing LIHR than previously. 10 (38%) were doubtful about its advantages, and six (23%,) were uncertain about its future and considered that it should only be performed within the context of a controlled trial. This study highlights a number of issues that need to be addressed before the role of LIHR can be determined.     

Primary and secondary sexual abstinence in high school students.

PURPOSE: To assess reasons for choosing not to have sexual intercourse among two groups: virgins (primary abstainers) and already sexually experienced youth (secondary abstainers). METHODS: 73,464 Minnesota ninth- and twelfth-grade adolescents completed the 1998 Minnesota Student Survey. Respondents identified reasons for abstinence from a checklist from which they could nominate all relevant items. Reasons for each group were analyzed using Chi-square with a conservative criterion value (p <.001) owing to large sample size. Logistic regression was used to examine the associations of gender, grade, and their interactions, with reasons for abstinence. RESULTS: Sixty-six percent reported never having had intercourse (primary abstainers). Among sexually experienced youth, 7.8% reported choosing not to have intercourse (secondary abstainers). Fear of pregnancy was the reason endorsed most often, more by girls than by boys (OR = 26 for primary abstainers, 6.9 for secondary abstainers). Fear of other adverse consequences, such as sexually transmitted infections, parental disapproval, or fear of getting caught, were generally selected by more girls than boys, and by more primary than secondary abstainers. Similarly, more girls and primary abstainers than boys or secondary abstainers generally selected statements reflecting normative beliefs on youth or their friends having intercourse. CONCLUSIONS: Fear of adverse consequences and normative beliefs about the appropriateness of having sexual intercourse were most frequently endorsed as important reasons by both groups of abstainers.     

Surface coat of sheep pulmonary intravascular macrophages: Reconstitution,and implication of a glycosyl-phosphatidylinositol anchor

Background: Pulmonary intravascular macrophages (PIMs) of sheep have a globular surface coat that facilitates endocytosis of tracer particles and Escherichia coli lipopolysaccharide, and is disrupted by the heparin and Brefeldin A treatments. The present study investigated the in vivo dynamics of the coat globules following heparin-mediated removal, and the mechanism of globule organization on the plasma membrane of PIMs in vitro. Methods: Sheep were administered heparin at a dose of 50 IU/kg body weight IV, and euthanised at 30 min, 3, 6, 12, 48, and 120 hr (n = 2 for each treatment) after the treatment. Control sheep (n = 2) were injected with normal saline solution. The tissues were processed for an ultrastructural examination and acid phosphatase (ACPase) cytochemistry. Heparintreated lungs were subjected to morphometric analysis of the coat globules. Lung tissues from normal sheep (n = 2) were incubated with phosphatidylinositol-specific-phospholipase C (PIPLC; 2 IU/ml PBS) in vitro for 30 and 75 min. Results: Heparin study: The ultrastructural and morphometric data showed that the coat globules were removed at 30 min and reconstituted within 48 hr of the treatment. The PIMs showed priminent Golgi complexes associated with secretory vesicles, microtubules, and centriole between 3–12 hr of heparin treatment. Acid phosphatase cytochemistry also demonstrated secretory activity in the Golgi complexes of PIMs during the coat reconstitution. PIPLC study: The coat globules of PIMs were removed in a time-dependent mode by the PIPLC treatment without damage to other cell organelles. Conclusions: This study demonstrates a time-dependent reconstitution of the coat of PIMs in conjunction with secretory activity following heparinmediated removal, probably through sequenstration of the globules from blood. This ability is of functional significance as the coat mediates particle endocytosis by the PIMs. The results also suggest the presence of a glycosyl-phosphatidylinositol (GPI) anchor in tethering of globules on the plasma membrane of PIMs to offer a structural basis for their integrity in pulmonary vascular flow. © 1995 Wiley-Liss, Inc.