Opioid pathways exert a tonic restraint in the guinea-pig isolated colon: changes after chronic sympathetic denervation

Abstract— We have studied the effects of naloxone on acetylcholine and noradrenaline release in the guinea-pig isolated distal colon, and have assessed the effect of naloxone on electrically-induced contractions of the longitudinal muscle and non-adrenergic, non-cholinergic (NANC) relaxations of the circular muscle coat. Naloxone dose-dependently increased resting and electrically-evoked acetylcholine release and electrically-evoked noradrenaline release. Naloxone was more potent in increasing resting acetylcholine release in colonic specimens obtained after chronic sympathetic denervation. Naloxone (1 μm ) did not affect electrically-induced contractions of the longitudinal muscle, while it enhanced NANC relaxations of the circular muscle. The effects observed with naloxone in the present experiments suggest that opioid pathways exert a tonic restraint on neurotransmission in the guinea-pig colon. After suppression of the adrenergic inhibitory tone, the functional relevance of opioid pathways seems to be increased.     

Idiotypic Vaccination: Immunoprotection Mediated by Anti-idiotypic Antibodies with Antibiotic Activity

Anti-Id antibodies were raised in mice against a monoclonal antibody (MoAb KT4) that neutralized the in vitro activity of a Pichia anomala yeast killer toxin. Monoclonal antibody was administered to BALB/C syngeneic mice with different schedules of immunization before intravenous challenge with increasing amounts of yeast killer toxin-sensitive Candida alhicans cells. The course of candidosis was studied in comparison with mice non-immunized and immunized with an isotypc-matched unrelated MoAb subdivided into control groups. Protection was reflected by statistically significant increases in survival rate of mice immunized with MoAb KT4 which showed variable serum levels of yeast killer toxin-like anti-Id antibodies. MoAb KT4 affinity chromatography purified mouse anti-Id antibodies were capable of killing in vitro the yeast ceils of the Candida albicans strain used for the experimental infection.
This is the first report of antimicrobial protection that exploits the role of anti-idiotypic antibodies presumably acting in vivo as antibiotics (idiotypic vaccination).     

Intravenous Versus Epidural Administration of Hydromorphone: Effects on Analgesia and Recovery after Radical Retropubic Prostatectomy

Background: It remains unclear whether epidural administration of hydromorphone results in spinal analgesia or clinical benefit when compared with intravenous administration. Therefore, we undertook this study to determine whether epidural administration of hydromorphone resulted in decreased opioid requirement, improved analgesia, reduced side effects, more rapid return of gastrointestinal function, or shorter duration of hospital stay than intravenous administration.

Methods: Sixteen patients undergoing radical retropubic prostatectomy were randomized in a double-blind manner to receive either intravenous or epidural hydromorphone via patient-controlled analgesia (PCA) for postoperative analgesia. All patients underwent a standardized combined epidural and general anesthetic and all received ketorolac for 72 h postoperatively. To decrease variability, patients were cared for according to a standardized protocol and were deemed ready for discharge according to prospectively defined criteria.

Results: Patients in the intravenous PCA group required approximately twice as much opioid than the epidural PCA group (P < 0.008), but there were no differences between groups in pain scores or patient satisfaction. Epidural administration resulted in a greater incidence of pruritus (P - 0.02). Gastrointestinal function recovered quickly in all patients with little variation, and there were no differences between groups. All patients were deemed ready for discharge by the third postoperative day, and removal of surgical drains was the last discharge criterion reached in all patients.     

Prospective Evaluation Of The Length Of The Lower Common Pathway In The Differential Diagnoss Of Various Forms Of AV Nodal Reentrant Tachycardia

The conduction time over the lower common pathway (LCP) in AVNRT can be assessed by subtracting the H A-interval during tachycardia (HA_t) from that during ventricular pacing at exactly the same cycle length (HAp) (ΔHA = HAp - HAt). tt has been suggested that H-A measurements may help in the differentiation of Slow/Fast from Slow/Slow AVNRT. This study evaluated prospectively in 61 consecutive patients with AVNRT (43 ± 15 y; 46 women, all with antegrade conduction during AVNRT over the slaw pathway) how often a reliable measurement of the length of the LCP could be made, and in how far the results were concordant with mapping criteria for the differentiation of Slow/Fast from Slow/Slow A VNRT. A new para-Hisian pacing technique (using only the His bundle catheter) was applied in all patients. Comparison of HAt and HAp was possible in 44 of the 61 patients (72%). In these 44 patients, HAp was longer than HAt in 12 patients, indicating the presence of a LCP. All patients with ΔHA ≥ 15 ms had earliest retrograde atrial activation in the posterior septum (Slow/Slow AVNRT, n = 6) or simultaneously in the anterior and posterior septum (n = 1). On the other hand, 31 of the 32 patients without evidence of a substantial LCP (ΔHA ≤ 0) had typical Slow/Fast AVNRT. Moreover, although it appears logical for Slow/Fast A VNRT to have a shorter HAt than Slow'Slow A VNRT, an HAp of ≥ 70 ms was a better discriminator between the two forms of AVNRT than any HAt value. Therefore, ΔHA ≥ 15 ms (sens. ≥86%; spec. ≥97%) or HAp ≥ 70 ms (sens. = 100%; spec. ≥89%) were highly indicative for the Slow/Slow variant of AVNRT. Using a para-Hisian pacing technique, H-A measurements can be performed in 72% of A VNRT patients. They can be used as an important tool in the differentiation of Slow/Fast and Slow/Slow A VNRT.     

Collagen fibril arrangement and size distribution in monkey oral mucosa

Collagen fibre organisation and fibril size were studied in the buccal gingival and hard palate mucosa of Macacus rhesus monkey. Light and electron microscopy analysis showed connective papillae exhibiting a similar inner structure in the different areas examined, but varying in distribution, shape and size. Moving from the deep to surface layers of the buccal gingival mucosa (free and attached portions), large collagen fibril bundles became smaller and progressively more wavy with decreasing collagen fibril diameter. This gradual diameter decrease did not occur in the hard palate mucosa (free portion, rugae and interrugal regions) where the fibril diameter remained constant. A link between collagen fibril diameter and mechanical function is discussed.     

Management of triplet pregnancies in the 1980s--are we doing better?

The incidence of triplet pregnancies has increased with the introduction of ovulation induction agents and is expected to further increase with the implementation of multiple embryo transfer in the in vitro fertilization programs. We review our experience with 29 triplet pregnancies in the last 10 years. Despite early sonographic diagnosis, close follow-up, increased use of tocolytics, and prophylactic cervical suture, we could not document prolongation of pregnancy, increased infants' weight, or a significantly decreased perinatal mortality, which still remains about 14%. Furthermore, the use of cesarean section as the delivery method of choice did not change the well-documented unfavorable relationship between birth order and fetal outcome. There is an urgent need for prospective assessment of the value of different treatment modalities, which nowadays becomes possible with the increasing incidence of triplet pregnancies. The prevention of triplet pregnancies or treatment by selective fetal reduction deserves a second thought.