A model for sperm-egg binding and fusion based on ADAMs and integrins.

Once a sperm meets an egg, several events must occur in order for fertilization to proceed. Sperm must bind to the zona pellucida, undergo the acrosome reaction, penetrate the zona pellucida and then bind to and fuse with the egg plasma membrane. Shortly thereafter, the egg must be activated for zygotic development. This review focuses on mammalian sperm-egg plasma membrane binding and fusion, and in particular on the roles of two families of cell-adhesion molecules, ADAMs and integrins, in this important union.

Sequence-specific interaction between the disintegrin domain of mouse ADAM 3 and murine eggs: role of beta1 integrin-associated proteins CD9, CD81, and CD98.

ADAM 3 is a sperm surface glycoprotein that has been implicated in sperm-egg adhesion. Because little is known about the adhesive activity of ADAMs, we investigated the interaction of ADAM 3 disintegrin domains, made in bacteria and in insect cells, with murine eggs. Both recombinant proteins inhibited sperm-egg binding and fusion with potencies similar to that which we recently reported for the ADAM 2 disintegrin domain. Alanine scanning mutagenesis revealed a critical importance for the glutamine at position 7 of the disintegrin loop. Fluorescent beads coated with the ADAM 3 disintegrin domain bound to the egg surface. Bead binding was inhibited by an authentic, but not by a scrambled, peptide analog of the disintegrin loop. Bead binding was also inhibited by the function-blocking anti-alpha6 monoclonal antibody (mAb) GoH3, but not by a nonfunction blocking anti-alpha6 mAb, or by mAbs against either the alphav or beta3 integrin subunits. We also present evidence that in addition to the tetraspanin CD9, two other beta1-integrin-associated proteins, the tetraspanin CD81 as well as the single pass transmembrane protein CD98 are expressed on murine eggs. Antibodies to CD9 and CD98 inhibited in vitro fertilization and binding of the ADAM 3 disintegrin domain. Our findings are discussed in terms of the involvement of multiple sperm ADAMs and multiple egg beta1 integrin-associated proteins in sperm-egg binding and fusion. We propose that an egg surface "tetraspan web" facilitates fertilization and that it may do so by fostering ADAM-integrin interactions.

Morphine, morphine-6-glucuronide and morphine-3-glucuronide concentrations in plasma and cerebrospinal fluid during long-term high-dose intrathecal morphine administration.

The kinetics of morphine, morphine-6-glucuronide (M6G), and morphine-3-glucuronide (M3G) were studied in a 56-year-old female with lung cancer. Long-term treatment with morphine intrathecally 28 mg every 6 h was used for pain control. Cerebrospinal fluid (CSF) concentrations of morphine were high with an elimination half-life of 2.1 h. The plasma/CSF ratios for M6G and M3G were 1:0.8 and 4:1, respectively, suggesting that M6G penetrates the blood-brain barrier more easily than M3G. The low CSF concentrations indicate that M6G played hardly any major analgetic role in the patient studied.

The effect of preoperative methylprednisolone on pulmonary function and pain after lung operations.

Thirty-six patients undergoing elective thoracotomy with pulmonary resection with the use of combined epidural and general anesthesia were randomized into a double-blind study to receive a single intravenous preoperative dose of methylprednisolone 25 mg/kg body weight or a placebo (saline solution). Postoperative pain relief consisted of epidural morphine 4 mg and paracetamol 1 gm three times a day for 4 days. Postoperative pulmonary function (peak expiratory flow rate, forced expiratory volume in first second, forced vital capacity) was evaluated on days 1, 2, 3, 4, and 7 and after 1 month. The value obtained after 1 month served as the control value. Pain score at rest and during cough was evaluated after 4 and 8 hours and on days 1, 2, 3, and 4. Pulmonary function was reduced after operation to the same degree in the steroid and placebo group: 42% versus 41% for forced expiratory volume in first second and 38% versus 39% for forced vital capacity, compared with control values after 1 month. Pain score was reduced in the steroid group after 4 hours and on day 1 during rest and after 4 and 8 hours and on day 2 during cough, compared with results in the placebo group (p < 0.05). In the steroid group three patients underwent reoperation because of leakage through the chest wall incision. In conclusion, administration of a single preoperative dose of methylprednisolone did not affect the postoperative reduction in pulmonary function after thoracotomy despite attenuated pain response, and the results do not warrant steroid administration before lung operation.

Effect of combined prednisolone, epidural analgesia, and indomethacin on the systemic response after colonic surgery.

Twenty patients undergoing colonic resection were randomized to either conventional postoperative pain treatment with morphine chloride and acetaminophen (group 1, n = 9) or methylprednisolone sodium succinate 90 minutes before surgery plus intraoperative neural blockade, with a postoperative analgesic regimen with combined bupivacaine hydrochloride-morphine and indomethacin sodium for systemic effect (group 2, n = 11). Assessments of pain, pulmonary function, convalescence, and various injury factors were done several times until 8 days after surgery. Postoperative pain and hyperthermic response were eliminated in group 2. Conventional reduction in pulmonary function measures was improved in group 2, and fatigue and mobility were less pronounced. Prostaglandin E2, interleukin 6, and C-reactive protein levels increased in both groups, but significantly less in group 2. These results suggest that a combined neural and humoral blockade may more effectively inhibit the global stress response to elective surgery than previously observed with neural blockade with or without indomethacin.

[Changes in mental function after anesthesia and surgery]. / Aendringer i den mentale funktion efter anaestesi og kirurgi.

Minor short-term depression of mental function is seen after anaesthesia and surgery. However, general anaesthesia does not seem to cause permanent damage or depress mental function beyond the first 2-4 postoperative days and no significant advantages of regional anaesthesia, as regards to cerebral function, are found after this period. Severe cases of long term mental deterioration after surgery and anaesthesia may be explained by other factors such as per- and postoperative complications. The risk of mental disturbance is increased in patients with psychiatric disease or presenile dementia and may be due to ongoing treatment with tricyclic antidepressant and neuroleptic drugs. Centrally acting cholinergic drugs, hypotension and hypoxia together with postoperative pain and sleep deprivation should be avoided.

[Long-term treatment with intrathecal morphine in severe painful cancer]. / Langtidsbehandling med morfin intratekalt ved svaere cancersmertetilstande.

Intrathecal treatment with morphine was instituted in seven cancer patients with severe pain. All of the patients had already received treatment with epidural morphine and the reason for the change in treatment was insufficient effect, side effects and/or pain connected with the injections in the epidural form of therapy. The duration of treatment was 5-136 days (median 40 days). The daily intrathecal dosage of morphine which was administered by 1-4 daily injections was initially 2.4-16.0 mg (median 3.6 mg) and had to be increased to 3.2-112 mg (median 16 mg) at the conclusion of treatment. Five patients became free from pain and one had acceptable relief of pain on this treatment. One patient received accidentally too great a dose of morphine intrathecally as compared with the usual dose and required treatment for respiratory insufficiency. Apart from postural headache on account of leakage of cerebro-spinal fluid, which could be treated by epidural blood "patch", the method was without complications which could be attributed to the intrathecally placed catheter. Treatment of pain with opioids injected intrathecally may thus be recommended in the cases in which epidural treatment cannot be carried out on account of the reasons mentioned above.

[Treatment of postoperative pain]. / Postoperativ smertebehandling.

Intensive research during recent years concerning treatment of postoperative pain has demonstrated that the majority of operation patients can be rendered free from pain but that this is far from being the case in clinical practice. This article reviews the physiological mechanisms of acute pain and the methods available for treatment of pain related to acute physiology of pain. Postoperative treatment of pain should be aggressive with the object of preventing pain and normalizing the vital functions with the object of reducing the perioperative morbidity and mortality. A series of recommendations are given for treatment of pain after surgical intervention.

Neurological sequelae after intoxication with sodium valproate.

A case of valproic acid poisoning with coma and neurological sequelae is presented. The course of the intoxication was severe with affection of the brain, heart and liver. The patient remained in coma for thirteen days. After this he recovered slowly although reduction in vision still persisted after two months. The toxicity of valproate is discussed.

Disruption of colonic anastomosis during continuous epidural analgesia. An early postoperative complication.

The clinical presentation is described of partial rupture of a colonic anastomosis two hours after surgery during epidural analgesia. The unusually early presentation of this complication is possibly due to removal of normal intestinal sympathetic activity by epidural analgesia resulting in normal or increased colonic motility. It is not known whether epidural analgesia may precipitate anastomotic breakdown due to increased contractions and strain on the anastomosis, or lead to an earlier presentation of a disruption caused by failure of surgical technique or other factors.

Comparison of the effects of continuous intrapleural vs epidural administration of 0.5% bupivacaine on pain, metabolic response and pulmonary function following cholecystectomy.

Twenty patients undergoing elective cholecystectomy were prospectively randomised to receive either intrapleural (bolus 20 ml followed by 10 ml/h) or thoracic epidural (bolus 9 ml followed by 5 ml/h) bupivacaine 0.5% for 8 h postoperatively to assess the effect of these two techniques on pain, pulmonary function and the surgical stress response. As assessed by the visual analogue scale (VAS), both groups received good but not total pain relief. Both groups had a 50% reduction in forced expiratory volume (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) after operation, and there was no observed effect on the stress response as measured by plasma glucose and cortisol. It is concluded that while both techniques provide good analgesia, the degree and extent of nerve blockade are not sufficient to affect the afferent neurogenic stimuli responsible for the observed effects on pulmonary function and the stress response.

Variation in spread of analgesia and loss of temperature discrimination during intermittent postoperative epidural bupivacaine administration.

The proximal-distal and bilateral extent of analgesia and loss of temperature discrimination were assessed during the initial 34.5 h after major abdominal surgery in ten patients receiving intermittent epidural bupivacaine injections according to a fixed dose regimen. Segmental spread of loss of temperature discrimination was invariably larger than analgesia at all times. During the later postoperative period (24-34 h) a pronounced intra-individual variation in both proximal-distal and bilateral spread of analgesia was observed despite identical epidural injections of bupivacaine. This variation in extent of analgesia was observed during injections of both 0.5% and 0.25% bupivacaine. The explanation of this observation is unknown but it may be shifts in catheter position, a variable disposition of the local anaesthetic agent or changes in the epidural space rather than tachyphylaxis.