Effect of omega-3-acid ethyl esters on steady-state plasma pharmacokinetics of atorvastatin in healthy adults.

BACKGROUND: Prescription omega-3-acid ethyl esters (P-OM3) have been used as adjunctive therapy to statin drugs in patients with mixed hyperlipidemia. OBJECTIVE: To assess the effect of concomitant administration of 4 g P-OM3 on the steady-state pharmacokinetics of the maximum recommended daily dose of atorvastatin (80 mg) in healthy volunteers. METHODS: This was a randomized, open-label, repeated-dose, two-way crossover, drug interaction study of two treatments: 4 g of P-OM3 with 80 mg atorvastatin daily or 80 mg atorvastatin daily, each administered for 14 days under fasting conditions to 50 healthy adults. MAIN OUTCOME MEASURES: The primary determinants of drug interaction were the ln-transformed area under the plasma concentration versus time curve (AUCtau) and maximum measured steady-state plasma concentration (C(max,ss)) over the final 24 h dosing interval (day 14) for atorvastatin and 2-hydroxyatorvastatin. Safety assessment included clinical laboratory evaluations and adverse event reporting. RESULTS: The extent and rate of exposure (AUCtau, C(max,ss)) to atorvastatin and its active metabolites following daily administration of P-OM3 with atorvastatin (80 mg) were similar to those following the administration of atorvastatin (80 mg) alone. Both treatments were well tolerated. CONCLUSIONS: After 14 days of dosing, the rate and extent of exposure (AUCtau, C(max,ss)) to atorvastatin and its active metabolites were similar with both treatments, indicating that administration of P-OM3 did not affect the steady-state bioavailability of orally administered atorvastatin.

Use of confocal linescan to document ciliary beat frequency.

We present a method to document ciliary beat frequency with the linescan function of a scanning confocal microscope, using ciliated tracheal cells and free-swimming rotifers as examples. Depending on the clarity of the original data, the ciliary beat frequency can be determined from the confocal linescan directly or from an intensity linescan analysis of the original data. Fast Fourier transform treatment of the data can be used to verify the derived ciliary beat frequency. The linescan approach allows analysis of simple ciliary movements displayed by the ciliated tracheal cells, as well as complex movements performed by free-swimming rotifers while feeding.

Extraction of near-field fluorescence from composite signals to provide high resolution images of glial cells.

The subdiffraction optical resolution that can be achieved using near-field optical microscopy has the potential to permit new approaches and insights into subcellular function and molecular dynamics. Despite the potential of this technology, it has been difficult to apply to cellular samples. One significant problem is that sample thickness causes the optical information to be comprised of a composite signal containing both near- and far-field fluorescence. To overcome this issue we have developed an approach in which a near-field optical fiber is translated toward the cell surface. The increase in fluorescence intensity during z-translation contains two components: a far-field fluorescence signal when the tip of the fiber is distant from the labeled cell, and combined near- and far-field fluorescence when the tip interacts with the cell surface. By fitting a regression curve to the far-field fluorescence intensity as the illumination aperture approaches the cell, it is possible to isolate near-field from far-field fluorescent signals. We demonstrate the ability to resolve actin filaments in chemically fixed, hydrated glial cells. A comparison of composite fluorescence signals with extracted near-field fluorescence demonstrates that this approach significantly increases the ability to detect subcellular structures at subdiffraction resolution.

Dose-response effect of combination hydrocodone with ibuprofen in patients with moderate to severe postoperative pain.

OBJECTIVE: The objective of this study was to demonstrate a dose-response effect with 1- and 2-tablet doses of combination hydrocodone 7.5 mg with ibuprofen 200 mg and placebo in patients with moderate to severe postoperative abdominal or gynecologic pain. BACKGROUND: Hydrocodone 7.5 mg with ibuprofen 200 mg is the only approved fixed-dose combination analgesic containing an opioid and ibuprofen. Previous studies with this combination have demonstrated that the components have an additive analgesic effect as well as efficacy compared with other fixed-dose combination analgesics. METHODS: This randomized, parallel-group, double-blind, single-dose, placebo-controlled study compared 1 tablet of hydrocodone 7.5 mg with ibuprofen 200 mg (n = 60), 2 tablets of hydrocodone 7.5 mg with ibuprofen 200 mg (n = 60), and placebo (n = 60) in patients with moderate or severe pain after abdominal or gynecologic surgery. Analgesia was evaluated over 8 hours. RESULTS: Mean pain relief (PR) scores were significantly greater for the 2-tablet dose than for the 1-tablet dose at 80 (P = 0.027) and 100 (P = 0.017) minutes and at 2 (P = 0.013), 2.5 (P = 0.012), 3 (P = 0.006), 4 (P = 0.029), 5 (P = 0.002), 6 (P = 0.032), 7 (P = 0.036), and 8 (P = 0.01) hours. Mean pain intensity difference scores were significantly greater for the 2-tablet dose than for the 1-tablet dose at 80 (P = 0.013) and 100 (P = 0.007) minutes and at 2 (P = 0.003), 2.5 (P = 0.002), 3 (P = 0.002), 4 (P = 0.009), 5 (P < 0.001), 6 (P = 0.004), 7 (P = 0.009), and 8 (P = 0.001) hours. Mean total PR scores were significantly greater for the 2-tablet dose than for the 1-tablet dose for all measured time intervals (0 to 3 hours, P = 0.01; 0 to 4 hours, P = 0.006; 0 to 6 hours, P = 0.003; 0 to 8 hours, P = 0.003). Mean sum of pain intensity differences was significantly greater for the 2-tablet dose than for the 1-tablet dose for all measured time intervals (0 to 3 hours, P = 0.004; 0 to 4 hours, P < 0.001; 0 to 6 hours, P < 0.001; 0 to 8 hours, P < 0.001). Mean peak PR score and median time-to-remedication were significantly greater for the 2-tablet dose than for the 1-tablet dose (P < 0.029 and P = 0.017, respectively). Both doses were superior to placebo. There were no significant differences in the number of patients experiencing adverse events between the 2-tablet dose (n = 6 [10.0%]), the 1-tablet dose (n = 4 [6.7%]), and placebo (n = 1 11.7%]). Adverse events were not serious, and none of the patients discontinued therapy because of side effects. CONCLUSIONS: This study demonstrated that a 2-tablet dose of hydrocodone with ibuprofen provided significantly more analgesia than a 1-tablet dose (a positive dose-response effect) and that both doses were superior to placebo.

Combination hydrocodone and ibuprofen versus combination codeine and acetaminophen for the treatment of chronic pain.

OBJECTIVE: The objective of this study was to compare the effectiveness of combination hydrocodone 7.5 mg and ibuprofen 200 mg with that of combination codeine 30 mg and acetaminophen 300 mg for the treatment of chronic pain. BACKGROUND: Hydrocodone 7.5 mg with ibuprofen 200 mg is the only approved fixed-dose combination analgesic containing an opioid and ibuprofen. METHODS: In this randomized, parallel-group, double-blind, repeated-dose, active-comparator, 4-week, multicenter study, 469 patients were randomly assigned to receive a 1-tablet (n = 156) or 2-tablet (n = 153) dose of combination hydrocodone 7.5 mg and ibuprofen 200 mg (HI1 and HI2, respectively) or a 2-tablet dose of combination codeine 30 mg and acetaminophen 300 mg (CA, n = 160), the active comparator, every 6 to 8 hours as needed for pain. Efficacy was measured through pain relief scores, number of daily doses of study medication, number of daily doses of supplemental analgesics, number of patients who discontinued therapy due to an unsatisfactory analgesic response, and global assessment scores. RESULTS: Of the 469 patients, 255 (54.4%) were female and 214 (45.6%) were male. The mean age was 51.1 years. Types of chronic pain included back (214; 45.6%), arthritic (145; 30.9%), other musculoskeletal (65; 13.9%), cancer (6; 1.3%), diabetic neuropathic (3; 0.6%), postherpetic neuralgic (5; 1.1%), other neurologic (21; 4.5%), and other unclassified chronic pain (10; 2.1%). During the 48 hours prior to the study, 351 (74.8%) patients had been treated with opioid or opioid-nonopioid combination analgesics. The overall mean daily pain relief score was significantly greater in the HI2 group (2.25+/-0.89) than in the HI1 group (1.98+/-0.87) (P = 0.003) or the CA group (1.85+/-0.96) (P < 0.001). The overall mean number of daily doses of study medication was significantly less in the HI2 group (2.94+/-0.99) than in the HI1 group (3.23+/-0.76) (P = 0.036) or the CA group (3.26+/-0.75) (P = 0.014). The overall mean number of daily doses of supplemental analgesics was significantly less in the HI2 group (0.24+/-0.49) than in the HI1 group (0.34+/-0.58) (P = 0.021) or CA group (0.49+/-0.85) (P = 0.010). The number of patients who discontinued treatment due to an unsatisfactory analgesic response was significantly less in the HI2 group (2; 1.3%) than in the CA group (12; 7.5%) (P = 0.008). HI2 was more effective than HI1 and CA as measured by pain relief scores for week 1 (P < 0.001 vs HI1 and CA), week 2 (P < 0.001 vs HI1 and CA), and week 3 (P = 0.008 vs HI1 and P < 0.001 vs CA); daily doses of study medication for week 1 (P = 0.019 vs HI1 and P = 0.011 vs CA); daily doses of supplemental analgesics for week 1 (P = 0.010 vs HI1 and CA); and global assessment scores for week 1 (P = 0.018 vs HI1 and P < 0.001 vs CA), week 2 (P = 0.005 vs HI1 and P < 0.001 vs CA), and week 4 (P = 0.013 vs HI1 and P = 0.023 vs CA). There were no significant differences between HI1 and CA in any efficacy variable. There were no significant differences in the number of patients experiencing adverse events in the HI2 (127; 83%), HI1 (124; 79.5%), and CA (129; 80.6%) groups. However, the mean number of patients who discontinued treatment due to adverse events was significantly greater in the HI2 group (40; 26.1%) than in the HI1 group (23; 14.7%) (P = 0.013). CONCLUSIONS: The results of this study suggest that 2-tablet doses of combination hydrocodone 7.5 mg and ibuprofen 200 mg may be more effective than either 1-tablet doses of this combination or 2-tablet doses of combination codeine 30 mg and acetaminophen 300 mg. Moreover, 1-tablet doses of combination hydrocodone 7.5 mg and ibuprofen 200 mg may be as effective as 2-tablet doses of combination codeine 30 mg and acetaminophen 300 mg.

Combination hydrocodone and ibuprofen versus combination oxycodone and acetaminophen in the treatment of postoperative obstetric or gynecologic pain.

OBJECTIVE: The objective of this study was to compare the effectiveness of combination hydrocodone and ibuprofen with that of combination oxycodone and acetaminophen in the treatment of moderate to severe postoperative obstetric or gynecologic pain. BACKGROUND: Hydrocodone 7.5 mg with ibuprofen 200 mg is the only approved fixed-dose combination analgesic containing an opioid and ibuprofen. METHODS: This randomized, double-blind, parallel-group, single-dose, active-comparator, placebo-controlled study compared the effects of a 2-tablet dose of hydrocodone 7.5 mg and ibuprofen 200 mg with those of a 2-tablet dose of oxycodone 5 mg and acetaminophen 325 mg and placebo. Analgesia was assessed over 8 hours. RESULTS: Mean pain relief (PR) scores were similar for the hydrocodone with ibuprofen and oxycodone with acetaminophen groups (n = 61 and 59, respectively) at 0.5, 1, 1.5, 2, 2.5, 3, 4, and 7 hours and significantly greater for the hydrocodone with ibuprofen group at 5, 6, and 8 hours (P < or = 0.05). Mean pain intensity difference (PID) scores were similar for hydrocodone with ibuprofen and oxycodone with acetaminophen at 0.5, 1, 1.5, 2, 2.5, 3, and 4 hours and significantly greater for hydrocodone with ibuprofen at 5, 6, 7, and 8 hours (P < or = 0.05). Total PR scores were similar for hydrocodone with ibuprofen and oxycodone with acetaminophen for the 0- to 3- and 0- to 4-hour intervals and significantly greater for hydrocodone with ibuprofen for the 0- to 6- and 0- to 8-hour intervals (P < 0.05). The sum of the PID scores was similar for hydrocodone with ibuprofen and oxycodone with acetaminophen for the 0- to 3-, 0- to 4-, 0- to 6-, and 0- to 8-hour intervals. The median estimated time to onset of analgesia, mean peak PR score, median time to remedication, and mean global assessment score were similar for hydrocodone with ibuprofen and oxycodone with acetaminophen. Assay sensitivity was demonstrated by the presence of statistically significant differences between both active treatments and placebo (n = 60). The number of patients experiencing adverse events was similar for each of the 3 groups (11 [18.0%], hydrocodone with ibuprofen; 7 [11.9%], oxycodone with acetaminophen; and 6 [10.0%], placebo). CONCLUSIONS: In this study, a 2-tablet dose of combination hydrocodone 7.5 mg and ibuprofen 200 mg was as effective as a 2-tablet dose of combination oxycodone 5 mg and acetaminophen 325 mg in the treatment of moderate to severe postoperative obstetric or gynecologic pain. Both treatments were superior to placebo. The results of this study suggest that the combination of hydrocodone 7.5 mg and ibuprofen 200 mg may offer prescribers an additional option in combination pain therapy.

SNARE protein-dependent glutamate release from astrocytes.

We investigated the cellular mechanisms underlying the Ca(2+)-dependent release of glutamate from cultured astrocytes isolated from rat hippocampus. Using Ca(2+) imaging and electrophysiological techniques, we analyzed the effects of disrupting astrocytic vesicle proteins on the ability of astrocytes to release glutamate and to cause neuronal electrophysiological responses, i.e., a slow inward current (SIC) and/or an increase in the frequency of miniature synaptic currents. We found that the Ca(2+)-dependent glutamate release from astrocytes is not caused by the reverse operation of glutamate transporters, because the astrocyte-induced glutamate-mediated responses in neurons were affected neither by inhibitors of glutamate transporters (beta-threo-hydroxyaspartate, dihydrokainate, and L-trans-pyrrolidine-2,4-dicarboxylate) nor by replacement of extracellular sodium with lithium. We show that Ca(2+)-dependent glutamate release from astrocytes requires an electrochemical gradient necessary for glutamate uptake in vesicles, because bafilomycin A(1), a vacuolar-type H(+)-ATPase inhibitor, reduced glutamate release from astrocytes. Injection of astrocytes with the light chain of the neurotoxin Botulinum B that selectively cleaves the vesicle-associated SNARE protein synaptobrevin inhibited the astrocyte-induced glutamate response in neurons. Therefore, the Ca(2+)-dependent glutamate release from astrocytes is a SNARE protein-dependent process that requires the presence of functional vesicle-associated proteins, suggesting that astrocytes store glutamate in vesicles and that it is released through an exocytotic pathway.

Subcellular distributions and excited-state processes of hypericin in neurons.

The photodynamic drug, hypericin, is studied in fetal rat neurons using fluorescence microscopy. Hypericin has an extremely high affinity for the cell membrane and is found to a smaller extent in the nucleus. Fluorescent excitation of hypericin is shown to cause irreversible damage to the cell membranes of living neurons. Fixed cells were used to make ultrafast time-resolved measurements to avoid the deleterious effects of long-term exposure to intense light and room temperatures. To our knowledge, these are the first ultrafast time-resolved measurements of the fluorescence lifetime of hypericin in a subcellular environment. Nonexponential fluorescence decay is observed in hypericin in the neurons. This nonexponential decay is discussed in terms of other examples where nonexponential decay is induced in hypericin upon its binding to biomolecules. The nonradiative processes giving rise to the nonexponential hypericin decay are attributed to excited-state electron transfer, excited-state proton transfer or both.

Analgesic efficacy of a combination of hydrocodone with ibuprofen in postoperative pain.

Two randomized, double-blind, parallel-group single-dose 2 x 2 factorial analgesic studies compared a single-dose or a 2-tablet dose of a combination of 7.5 mg hydrocodone bitartrate with 200 mg ibuprofen with each constituent alone and with a placebo in women with moderate or severe postoperative pain from abdominal or gynecologic surgery. A nurse-observer recorded patient reports of pain intensity and pain relief periodically for 8 hours. In both studies, the combination was significantly superior to placebo for sum of the pain intensity differences (SPID), total pain relief (TOTPAR), peak pain intensity difference (PID) and pain relief, global evaluation, and time to remedication. The combination was likewise significantly superior to both hydrocodone and ibuprofen for most of these summary measures of analgesia. In a factorial analysis, both the hydrocodone and ibuprofen effects were significant for most summary measures of analgesia, whereas results of the interaction contrast were consistent with the concept that the analgesic effect of the combination represents the additive analgesia of its 2 constituents.

Contact-dependent regulation of N-type calcium channel subunits during synaptogenesis.

The developmental regulation of the N-type calcium channel during synaptogenesis was studied using cultured rat hippocampal neurons to elucidate the roles of extrinsic versus intrinsic cues in the expression and distribution of this channel. Prior to synapse formation, alpha1B and beta3 subunits of the N-type calcium channel were distributed diffusely throughout neurites, growth cones, and somata. As synaptogenesis proceeded, the subunit distributions became punctate and colocalized with the synaptic vesicle protein synaptotagmin. Isolated neurons were also examined to test for the requirement of extrinsic cues that control N-type calcium channel expression and distribution. These neurons expressed N-type calcium channel subunits, but their distributions remained diffuse. Functional omega-conotoxin GVIA-sensitive channels were expressed in isolated neurons, although the distribution of alpha1B subunits was diffuse. The distribution of the alpha1B subunit and synaptotagmin only became punctate when neuron-neuron contact was allowed. Thus, the expression of functional N-type calcium channels is the result of an intrinsic program while extrinsic regulatory cues mediated by neuron-neuron contact are required to control their distribution during synaptogenesis.

Calcium-independent activation of the secretory apparatus by ruthenium red in hippocampal neurons: a new tool to assess modulation of presynaptic function.

The functional plasticity of the nervous system may result in part from the direct modulation of the effectiveness of the release machinery of synaptic terminals. To date, direct modulation of secretion in neurons has proven difficult to study because of the lack of a suitable tool to probe the release machinery independently of calcium influx. We report that the polyvalent cation ruthenium red (RR) directly evokes rapid and reversible calcium-independent quantal secretion in hippocampal neurons by binding to external sites on the presynaptic terminal membrane. This binding can be displaced by heparin and is not associated with ultrastructural damage to the synaptic terminals. The use of RR-evoked release as a tool has allowed us to detect a direct modulation of the secretory apparatus after activation of A1 adenosine receptors on hippocampal neurons.

Dynamic imaging of purified individual synaptic vesicles.

The atomic force microscope (AFM) was used to directly image purified synaptic vesicles. Individual secretory vesicles (approximately 50 nm diameter) were resolved with the AFM when imaged either dry or in solution. Vesicles were observed repeatedly for periods of greater than 2 h. To ask whether the AFM can detect structural change of vesicles the osmolarity of the bathing medium was reduced from 330 to 110 mOsm. Hypo-osmotic treatment caused an expansion and flattening of the vesicles. Thus, using the AFM it is possible to resolve individual vesicles and follow changes in vesicular structure. This opens the possibility that the secretory event can be reconstituted and visualized in vitro in order to elucidate the roles of synaptic proteins in synaptic transmission.

FMRFamide modulation of secretory machinery underlying presynaptic inhibition of synaptic transmission requires a pertussis toxin-sensitive G-protein.

The neuropeptide FMRFamide modulates synaptic transmission between identified neurons of the pond snail Helisoma trivolvis. FMRFamide causes a presynaptic inhibition of transmitter release by actions on ion channels and secretory machinery (Man-Son-Hing et al., 1989). The actions of FMRFamide on secretory machinery were studied using giant synapses that form between somata in culture. Using the calcium cage DM-nitrophen, synchronized, calcium-clamped release of neurotransmitter was promoted by UV photolysis. A series of UV flashes (15 msec duration) repeatedly promoted the transient synchronized release of neurotransmitter. Addition of FMRFamide reduced the magnitude of these flash-evoked inhibitory postsynaptic currents. Under conditions of synchronized transmitter release, FMRFamide modulates the secretory responsiveness to internal calcium. The release of neurotransmitter at somasoma synapses was determined to be quantal in nature. To test for the involvement of G-proteins in mediating the effects of FMRFamide on secretory machinery, the modulation of the frequency of miniature inhibitory postsynaptic currents (MIPSCs) was examined. Addition of FMRFamide reduced the frequency of MIPSCs without affecting intracellular free calcium measured with fura-2. Injection of a nonhydrolyzable analog of GTP, GTP gamma S, mimicked the effect of FMRFamide and reduced MIPSC frequency. Preinjection of the presynaptic soma with the A-protomer of pertussis toxin (PTX) prevented FMRFamide from reducing MIPSC frequency. Thus, a PTX-sensitive G-protein mediates the action of FMRFamide on secretory machinery. Similarly, preinjection of the presynaptic soma with PTX prevented FMRFamide from reducing the magnitude of action potential-evoked IPSC. Dose-response curves for the actions of FMRFamide on secretory machinery and calcium current were constructed and demonstrated that secretory machinery can be modulated at concentrations of FMRFamide (less than or equal to 10(-7) M) that do not affect calcium current magnitude. At a concentration of 10(-7) M FMRFamide, action potential-evoked synaptic transmission was reduced. Thus, synaptic transmission can be regulated by the modulation of secretory machinery, without a requirement for the modulation of ion channels.

Target contact regulates the calcium responsiveness of the secretory machinery during synaptogenesis.

Neuron B19 of Helisoma is selective in synaptogenesis. Presynaptic mechanisms underlying this selectivity were tested. Acetylcholine-sensitive assay cells were micromanipulated into contact with B19 somata to assess its secretory state. Prior to appropriate muscle target contact, spontaneous synaptic currents were detected; however, action potential-evoked release of neurotransmitter was detected only following hours of muscle contact. Photolysis of a calcium cage, DM-nitrophen, accelerated the frequency of synaptic currents in muscle-contacted, but not novel neuron-contacted, B19 somata. These studies demonstrate that contact with appropriate target muscle enhances the responsiveness of this neuron's secretory machinery to internal calcium levels, thereby imparting the presynaptic cell with the ability to couple action potentials with neurotransmitter release.

Target-dependent induction of secretory capabilities in an identified motoneuron during synaptogenesis.

Cholinergic neurons isolated from the buccal ganglia of Helisoma were plated into cell culture with a variety of defined target cells to study the specificity of synaptogenesis. Motoneuron B19 selectively formed chemical connections with single dissociated muscle fibers derived from its appropriate target, the supralateral radular tensor (SLT) muscle. B19 did not form such connections with novel neuronal targets. In contrast to neuron B19, cholinergic neuron B5 nonselectively formed chemical connections with novel muscle and neuronal targets. Target cells were micromanipulated into contact with presynaptic neurons to examine the latent period until the onset of functional synaptic transmission. Neuron B5 formed chemical connections within the first minutes of contact with ACh-sensitive neurons and muscle while B19 required sustained periods of muscle-specific contact to induce the acquisition of a functional excitation-secretion coupling mechanism. These different latent periods from the onset of target contact suggest that neuron B5 acquires presynaptic secretory function before target contact, while B19 must receive a specific signal(s) from its appropriate target to induce the transformation of its terminal into a secretory state.

A relation between synaptic specificity and the acquisition of presynaptic properties.

1. The specificity of synaptogenesis of identified adult neurons of Helisoma was determined in cell culture. Cholinergic neuron B5 indiscriminately forms the presynaptic element of chemical connections with novel cholinoceptive target neurons and muscle. By contrast, cholinergic neuron B19 is selective and discriminates between novel and appropriate target cells. Neuron B19 forms chemical connections with appropriate muscle targets only. 2. The acquisition of presynaptic properties independent of target contact was studied for both identified neurons. Functional connections form between neuron B5 and novel targets within seconds of contact, indicating that this cell has synthesized the presynaptic apparatus before target contact. In contrast, neuron B19 showed no evidence of possessing the ability to release neurotransmitter. 3. To further study the development of presynaptic properties, a model system of giant synaptic terminals was developed. The soma of neuron B5, acutely isolated from the nervous system is non-secretory. In conditions that prevent the extension of neurites, somata gain the ability to release neurotransmitter. This experimentally tractable system was used to study the calcium currents of presynaptic neuron B5. Acutely-isolated non-secretory somata contain two types of calcium currents: low-voltage-activated (LVA) and high-voltage-activated (HVA). The types of calcium currents in the soma change when B5 gains its secretory capacity. Secretory somata contain HVA calcium current only. 4. Neuron B5 was also plated in conditions which permit the extension of neurites. LVA and HVA calcium currents were maintained in its soma (non-secretory) but HVA calcium current only was maintained in its growth cones (secretory). Thus, B5 differentially regulates the presence of specific calcium currents in its membrane in relation to local secretory capacity without target-derived cues. 5. These data suggest that neuron B5 has an intrinsic program which generates presynaptic calcium channels and secretory apparatus prior to target contact. This autonomy of initial presynaptic development may underlie the lack of target cell discrimination exhibited by B5 in synaptogenesis.

Clinical evaluation and prerelease management of American river otters in the second year of a reintroduction study.

In the first year (1984) of a reintroduction study, 10 American river otters (Lutra canadensis) from Louisiana were transported to Oklahoma, held for 5 days for clinical evaluation, surgical implantation with intra-abdominal radiotelemetry devices, and then released in Oklahoma. Four of 10 otters released died within 32 days. Clinical evaluation indicated that respiratory tract disease, bacterial and parasitic infections, and inanition may have contributed to the death of these otters. In the second year (1985) of the study, an exotic feline diet was fed, and the holding period for 10 otters was increased to provide time for evaluation and treatment before surgery, postsurgical acclimation to Oklahoma, and reevaluation before release. Although the initial clinical findings on otters in the second year were similar to those found in the first year, otter body weights increased, and the prevalence and severity of clinical abnormalities decreased with treatment during the second-year holding period. Three of 10 second-year otters died during the holding period, and contributing causes of death were determined to be: trauma (hepatic hematoma), inanition, renal disease, pneumonia, salmonellosis (Salmonella anatum), and a retropharyngeal abscess (Klebsiella pneumoniae). Seven healthy otters were reintroduced into Oklahoma in 1985, and postrelease deaths were not experienced.